Cisco UBR924 Router Software Configuration Guide Systems Network Scg924bk

User Manual: Cisco Systems Network Router UBR924

Open the PDF directly: View PDF .
Page Count: 134

Download
Open PDF In Browser	View PDF

Cisco uBR924 Cable Access Router
Software Configuration Guide
12.2(8)
August 2002

Corporate Headquarters
Cisco Systems, Inc.
170 West Tasman Drive
San Jose, CA 95134-1706
USA
http://www.cisco.com
Tel: 408 526-4000
800 553-NETS (6387)
Fax: 408 526-4100

Text Part Number: OL-0337-05

THE SPECIFICATIONS AND INFORMATION REGARDING THE PRODUCTS IN THIS MANUAL ARE SUBJECT TO CHANGE WITHOUT NOTICE. ALL
STATEMENTS, INFORMATION, AND RECOMMENDATIONS IN THIS MANUAL ARE BELIEVED TO BE ACCURATE BUT ARE PRESENTED WITHOUT
WARRANTY OF ANY KIND, EXPRESS OR IMPLIED. USERS MUST TAKE FULL RESPONSIBILITY FOR THEIR APPLICATION OF ANY PRODUCTS.
THE SOFTWARE LICENSE AND LIMITED WARRANTY FOR THE ACCOMPANYING PRODUCT ARE SET FORTH IN THE INFORMATION PACKET THAT
SHIPPED WITH THE PRODUCT AND ARE INCORPORATED HEREIN BY THIS REFERENCE. IF YOU ARE UNABLE TO LOCATE THE SOFTWARE LICENSE
OR LIMITED WARRANTY, CONTACT YOUR CISCO REPRESENTATIVE FOR A COPY.
The Cisco implementation of TCP header compression is an adaptation of a program developed by the University of California, Berkeley (UCB) as part of UCB’s public
domain version of the UNIX operating system. All rights reserved. Copyright © 1981, Regents of the University of California.
NOTWITHSTANDING ANY OTHER WARRANTY HEREIN, ALL DOCUMENT FILES AND SOFTWARE OF THESE SUPPLIERS ARE PROVIDED “AS IS” WITH
ALL FAULTS. CISCO AND THE ABOVE-NAMED SUPPLIERS DISCLAIM ALL WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING, WITHOUT
LIMITATION, THOSE OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OR ARISING FROM A COURSE OF
DEALING, USAGE, OR TRADE PRACTICE.
IN NO EVENT SHALL CISCO OR ITS SUPPLIERS BE LIABLE FOR ANY INDIRECT, SPECIAL, CONSEQUENTIAL, OR INCIDENTAL DAMAGES, INCLUDING,
WITHOUT LIMITATION, LOST PROFITS OR LOSS OR DAMAGE TO DATA ARISING OUT OF THE USE OR INABILITY TO USE THIS MANUAL, EVEN IF CISCO
OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
CCIP, the Cisco Arrow logo, the Cisco Powered Network mark, the Cisco Systems Verified logo, Cisco Unity, Follow Me Browsing, FormShare, Internet Quotient, iQ
Breakthrough, iQ Expertise, iQ FastTrack, the iQ Logo, iQ Net Readiness Scorecard, Networking Academy, ScriptShare, SMARTnet, TransPath, and Voice LAN are
trademarks of Cisco Systems, Inc.; Changing the Way We Work, Live, Play, and Learn, Discover All That’s Possible, The Fastest Way to Increase Your Internet Quotient,
and iQuick Study are service marks of Cisco Systems, Inc.; and Aironet, ASIST, BPX, Catalyst, CCDA, CCDP, CCIE, CCNA, CCNP, Cisco, the Cisco Certified Internetwork
Expert logo, Cisco IOS, the Cisco IOS logo, Cisco Press, Cisco Systems, Cisco Systems Capital, the Cisco Systems logo, Empowering the Internet Generation,
Enterprise/Solver, EtherChannel, EtherSwitch, Fast Step, GigaStack, IOS, IP/TV, LightStream, MGX, MICA, the Networkers logo, Network Registrar, Packet, PIX,
Post-Routing, Pre-Routing, RateMUX, Registrar, SlideCast, StrataView Plus, Stratm, SwitchProbe, TeleRouter, and VCO are registered trademarks of Cisco Systems, Inc.
and/or its affiliates in the U.S. and certain other countries.
All other trademarks mentioned in this document or Web site are the property of their respective owners. The use of the word partner does not imply a partnership relationship
between Cisco and any other company. (0206R)
Cisco uBR924 Cable Access Router
Software Configuration Guide
OL-0337-05
Copyright © 2000-2002, Cisco Systems, Inc.
All rights reserved.

C O N T E N T S
Preface

vii

Audience
Purpose

vii
viii

Organization

viii

Document Conventions
Acronyms and Terms

viii
xi

Related Documentation xii
Cisco uBR924 Cable Access Router xii
CMTS Hardware Installation Publications xiii
Cisco IOS Publications xiii
Configuration Editor and Network Management Publications
Subscriber Publications xiii

xiii

Obtaining Documentation xiv
World Wide Web xiv
Documentation CD-ROM xiv
Ordering Documentation xiv
Obtaining Technical Assistance xiv
Cisco Connection Online xiv
Technical Assistance Center xv
Documentation Feedback xv

CHAPTER

Overview

1-1

Cisco IOS Software Release Feature Sets 1-1
Base IP DOCSIS-Compliant Bridging 1-2
Home Office (Easy IP) 1-3
Value Telecommuter 1-4
Performance Telecommuter 1-4
Value Small and Branch Office 1-4
Performance Small and Branch Office 1-5
Feature Descriptions 1-5
Cable Monitor Web Diagnostics Tool 1-5
Cisco Cable Clock Card Support 1-5
Cisco IOS Firewall 1-5
DOCSIS-Compliant Bridging 1-6
Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

iii

Contents

DOCSIS Baseline Privacy Interface 1-6
Dynamic Host Configuration Protocol Server 1-6
Dynamic Host Configuration Protocol Proxy Support 1-7
Enhanced IP Bridging 1-7
Ecosystem Gatekeeper Interoperability Enhancements 1-7
Fax over IP 1-8
H.323v2 (Gateway/Gatekeeper) 1-8
IP Address Negotiation 1-9
IPsec Network Security 1-9
Layer 2 Tunneling Protocol 1-9
Media Gateway Control Protocol V12.1.3T 1-10
NetRanger Support—Cisco IOS Intrusion Detection 1-10
Network Address Translation and Port Address Translation 1-10
Network Address Translation Support for NetMeeting Directory (Internet Locator Service)
Quality of Service 1-11
Quality of Service—DOCSIS 1.0+ Extensions 1-11
Routing Information Protocol Version 2 1-12
Secure Shell Version 1 1-12
Simple Gateway Control Protocol 1-12
Triple Data Encryption Standard 1-13
VPN IPsec Enhancement—Dynamic Crypto Map 1-13
Initial Provisioning

1-10

1-14

Supporting Multiple Classes of Service 1-15
DOCSIS 1.0 Static Profiles 1-15
DOCSIS 1.0+ and 1.1 Dynamic Profiles 1-15
Creating Multiple Profiles 1-16
User Registrar 1-16
Modem Registrar 1-17
Cisco Network Registrar 1-17
Access Registrar 1-17

CHAPTER

DOCSIS-Bridging Configuration
DHCP Server Configuration

2-1

2-2

DOCSIS Configuration File

2-3

Cisco IOS Software Image

2-6

Cisco IOS Configuration File 2-7
Using the Vendor-Specific Information Field 2-7
Sample Configuration for DOCSIS-Compliant Bridging
Configuring the Attached CPE Devices

2-8

2-9

Cisco uBR924 Software Configuration Guide

OL-0337-05 (8/2002)

Contents

Reconfiguring DOCSIS-Compliant Bridging

CHAPTER

Advanced Data-Only Configurations
Data-Only Routing

2-9

3-1

3-2

Routing with DHCP Server
NAT/PAT Configuration

3-4
3-6

NAT/PAT Configuration with DHCP Proxy 3-8
Using NAT and DHCP Proxy and Copying Configuration Files

3-10

IPSec (56-bit) Example 3-11
Sample Configuration 3-13
Additional Documentation 3-15
IPSec (3DES) Example
L2TP Example

CHAPTER

3-16

3-17

Voice over IP Configurations

4-1

Overview 4-1
Introduction 4-2
Voice Handling 4-4
Quality of Service Support 4-4
H.323v2 Protocol 4-5
SGCP and MGCP Protocol Stack

4-6

H.323v2 Static Bridging Configuration

4-7

H.323v2 Static Routing Configuration

4-10

H.323v2 Dynamic Mapping Configuration
SGCP Configuration
MGCP Configuration

APPENDIX

4-11

4-15
4-18

Using Cisco IOS Software

A-1

Accessing the Router’s Command-Line Interface
Connecting Using Telnet A-2
Connecting to the Console Port A-2

A-1

Understanding the Command-Line Interface A-3
Command Modes A-3
User EXEC Mode A-4
Privileged EXEC Mode A-4
Global Configuration Mode A-5
Interface Configuration Mode A-5
Context-Sensitive Help A-6
Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

Contents

Command History Features A-7
Displaying the Command History A-7
Editing Previous Commands A-7
Command History Buffer Size A-8
Using Output Modifiers A-8
Understanding Cisco IOS Configuration Files A-9
Downloading the Configuration File A-9
Startup and Run-Time Configuration Files A-10
Displaying the Configuration Files A-10
File Format A-11
Useful Commands

APPENDIX

A-11

Using the Cable Monitor Tool

B-1

Enabling the Cable Monitor B-2
Configuration Modes B-2
Security Considerations B-3
Disabling the Cable Monitor

B-3

Accessing the Cable Monitor B-4
Through the Cable Interface when the Cable Interface is Operational B-4
Through the Ethernet Interface when the Cable Interface is Not Operational

B-5

Sample Pages B-6
Home Page B-8
Initialization Information B-10
Voice Ports Information B-13
CPE State Information B-15
Cable Interface Information B-17
Performance Information B-19
Debug Information Page B-21

APPENDIX

Using the ROM Monitor

C-1

Entering the ROM Monitor
Command Conventions
Commands

APPENDIX

C-1

C-2

New and Changed Commands Reference
Commands Reserved for DOCSIS Use

D-1

INDEX

Cisco uBR924 Software Configuration Guide

OL-0337-05 (8/2002)

Preface
This document is the Cisco uBR924 Cable Access Router Software Configuration Guide and describes
the configuration of the Cisco uBR924 cable access router. This section describes the following topics:
•

Audience

•

Purpose

•

Organization

•

Document Conventions

•

Acronyms and Terms

•

Related Documentation

•

Obtaining Documentation

•

Obtaining Technical Assistance

Audience
This configuration guide is designed for system administrators who have some experience downloading
software from the World Wide Web and configuring cable modem/router systems. This guide is also
directed to the network administrators who are responsible for administering the customer’s local area
network.
All users should have some experience with configuring Cisco routers and using the Cisco IOS
command-line interface (CLI). A basic familiarity with DOCSIS 1.0, DOCSIS 1.0+ quality of service
(QoS) principles, H.323, and SGCP/MGCP is helpful.
Cable system installers and technicians should be familiar with their cable plant’s base operating
parameters and subscriber service offerings. Cable system support engineers and administrators should
be acquainted with cable data networks and WAN communications protocols. Network administrators
should be familiar with the principles of IP routing and subnetting; some of the advanced configurations
also require a thorough understanding of access lists and how to use them.

Note

This document contains instructions to install or configure the Cisco uBR924 cable access router using
procedures that only qualified personnel should perform. This document is not intended for subscribers.
Refer to the “Subscriber Publications” section of this preface for a list of documents available for
subscribers.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

vii

Preface
Purpose

Purpose
This configuration guide explains the initial and basic software configuration procedures for the
Cisco uBR924 cable access router. This guide contains procedures for configuring the
Cisco uBR924 router for both data only operation, as well as for voice and data operation. This guide
also describes how to set up basic security, the headend interface (CMTS-to-CM), and how to use ROM
monitor.

Organization
This guide is organized into the chapters and appendixes shown in Table 1, which also shows the changes
from the previous version of this guide:
Table 1

Organization

Chapter

Title

Description

Changes from the Previous
Release

Chapter 1

Overview

Provides an overview of the Cisco uBR924 cable
access router and its possible configurations.

Includes features added in
Cisco IOS Release 12.1(5)T.

Chapter 2

DOCSIS-Bridging
Configuration

Describes how to configure the router for its
None.
default of DOCSIS-compliant bridging operation.

Chapter 3

Advanced Data-Only
Configurations

Describes how to configure the router for various None.
data-only configurations such as routing operation
and IPSec encryption.

Chapter 4

Voice over IP
Configurations

Describes how to configure the router for Voice
None.
over IP (VoIP) traffic using either the H.323v2 or
SGCP/MGCP call control protocols.

Appendix A Using Cisco IOS
Software

Describes the basics of using the Cisco IOS
command line interface (CLI).

None.

Appendix B Using the Cable
Monitor Tool

Describes how to display diagnostic information None.
about the Cisco uBR924 cable access router using
any web browser.

Appendix C Using the ROM Monitor Describes how to use the Cisco IOS ROM
monitor.

Minor changes on entering
ROMMON mode and returning
to normal mode.

Appendix D New and Changed
Commands Reference

Includes commands added in
Cisco IOS Release 12.1(5)T.

Note

Lists the commands that are new to the
Cisco IOS 12.1 T software releases.

For a complete list of changes in each Cisco IOS release, see the Release Notes that accompany that
release.

Document Conventions
This publication uses the following conventions:

Cisco uBR924 Software Configuration Guide

viii

OL-0337-05 (8/2002)

Preface
Document Conventions

Convention

Meaning

Comments

Boldface

Commands and keywords you enter offset-list
literally as shown

Italics

Variables for which you supply
values

command type interface
You replace the variable with the type of
interface.
In contexts that do not allow italics, such
as online help, arguments are enclosed in
angle brackets (< >).

Square brackets ([ ])

Optional elements

command [abc]
abc is optional (not required), but you can
choose it.

Vertical bars ( | )

Separated alternative elements

command [ abc | def ]
You can choose either abc or def, or
neither, but not both.

Braces ({ })

Required choices

command { abc | def }
You must use either abc or def, but not
both.

Braces and vertical bars within square
brackets ([ { | } ])

A required choice within an
optional element

command [ abc { def | ghi } ]
You have three options:
•

Nothing

•

abc def

•

abc ghi

Caret character (^)

Control key

The key combinations ^D and Ctrl-D are
equivalent: Both mean hold down the
Control key while you press the D key.
Keys are indicated in capital letters, but
are not case sensitive.

A string

A non-quoted set of characters

For example, when setting an SNMP
community string to public, do not use
quotation marks around the string;
otherwise, the string will include the
quotation marks.

System prompts

Denotes interactive sessions,
indicates that the user enters
commands at the prompt

The system prompt indicates the current
command mode. For example, the prompt
Router (config) # indicates global
configuration mode.

Screen

font

Angle brackets (< >)

Terminal sessions and information
the system displays
Non-printing characters such as
passwords

Exclamation points (!) at the beginning of A comment line
a line

Comments are sometimes displayed by the
Cisco IOS software.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

Preface
Document Conventions

Caution

Note

Timesaver

Means reader be careful. You are capable of doing something that might result in equipment damage or
loss of data.

Means reader take note. Notes contain helpful suggestions or references to materials not contained in
this guide.

Means the described action saves time. You can save time by performing the action described in the
paragraph.

Warning

This warning symbol means danger. You are in a situation that could cause bodily injury. Before you
work on any equipment, be aware of the hazards involved with electrical circuitry and be familiar
with standard practices for preventing accidents. (To see translations of the warnings that appear
in this publication, refer to the appendix, “Translated Safety Warnings,” in the installation guide
that accompanied this device.)

Waarschuwing

Dit waarschuwingssymbool betekent gevaar. U verkeert in een situatie die lichamelijk letsel kan
veroorzaken. Voordat u aan enige apparatuur gaat werken, dient u zich bewust te zijn van de bij
elektrische schakelingen betrokken risico’s en dient u op de hoogte te zijn van standaard
maatregelen om ongelukken te voorkomen. (Voor vertalingen van de waarschuwingen die in deze
publicatie verschijnen, kunt u het aanhangsel “Translated Safety Warnings” (Vertalingen van
veiligheidsvoorschriften) in de installatiegids die bij dit toestel is ingesloten, raadplegen.

Varoitus

Tämä varoitusmerkki merkitsee vaaraa. Olet tilanteessa, joka voi johtaa ruumiinvammaan. Ennen
kuin työskentelet minkään laitteiston parissa, ota selvää sähkökytkentöihin liittyvistä vaaroista ja
tavanomaisista onnettomuuksien ehkäisykeinoista. (Tässä julkaisussa esiintyvien varoitusten
käännökset löydät tämän laitteen mukana olevan asennusoppaan liitteestä “Translated Safety
Warnings” (käännetyt turvallisuutta koskevat varoitukset).)

Attention

Ce symbole d’avertissement indique un danger. Vous vous trouvez dans une situation pouvant
entraîner des blessures. Avant d’accéder à cet équipement, soyez conscient des dangers posés par
les circuits électriques et familiarisez-vous avec les procédures courantes de prévention des
accidents. Pour obtenir les traductions des mises en garde figurant dans cette publication, veuillez
consulter l’annexe intitulée « Translated Safety Warnings » (Traduction des avis de sécurité) dans
le guide d’installation qui accompagne cet appareil.

Warnung

Dieses Warnsymbol bedeutet Gefahr. Sie befinden sich in einer Situation, die zu einer
Körperverletzung führen könnte. Bevor Sie mit der Arbeit an irgendeinem Gerät beginnen, seien Sie
sich der mit elektrischen Stromkreisen verbundenen Gefahren und der Standardpraktiken zur
Vermeidung von Unfällen bewußt. (Übersetzungen der in dieser Veröffentlichung enthaltenen
Warnhinweise finden Sie im Anhang mit dem Titel “Translated Safety Warnings” (Übersetzung der
Warnhinweise) in der diesem Gerät beiliegenden Installationsanleitung.)

Cisco uBR924 Software Configuration Guide

OL-0337-05 (8/2002)

Preface
Acronyms and Terms

Avvertenza

Questo simbolo di avvertenza indica un pericolo. Si è in una situazione che può causare infortuni.
Prima di lavorare su qualsiasi apparecchiatura, occorre conoscere i pericoli relativi ai circuiti
elettrici ed essere al corrente delle pratiche standard per la prevenzione di incidenti. La traduzione
delle avvertenze riportate in questa pubblicazione si trova nell’appendice, “Translated Safety
Warnings” (Traduzione delle avvertenze di sicurezza), del manuale d’installazione che
accompagna questo dispositivo.

Advarsel

Dette varselsymbolet betyr fare. Du befinner deg i en situasjon som kan føre til personskade. Før du
utfører arbeid på utstyr, må du være oppmerksom på de faremomentene som elektriske kretser
innebærer, samt gjøre deg kjent med vanlig praksis når det gjelder å unngå ulykker. (Hvis du vil se
oversettelser av de advarslene som finnes i denne publikasjonen, kan du se i vedlegget “Translated
Safety Warnings” [Oversatte sikkerhetsadvarsler] i installasjonsveiledningen som ble levert med
denne enheten.)

Aviso

Este símbolo de aviso indica perigo. Encontra-se numa situação que lhe poderá causar danos
fisicos. Antes de começar a trabalhar com qualquer equipamento, familiarize-se com os perigos
relacionados com circuitos eléctricos, e com quaisquer práticas comuns que possam prevenir
possíveis acidentes. (Para ver as traduções dos avisos que constam desta publicação, consulte o
apêndice “Translated Safety Warnings” - “Traduções dos Avisos de Segurança”, no guia de
instalação que acompanha este dispositivo).

Advertencia

Este símbolo de aviso significa peligro. Existe riesgo para su integridad física. Antes de manipular
cualquier equipo, considerar los riesgos que entraña la corriente eléctrica y familiarizarse con los
procedimientos estándar de prevención de accidentes. (Para ver traducciones de las advertencias
que aparecen en esta publicación, consultar el apéndice titulado “Translated Safety Warnings,” en
la guía de instalación que se acompaña con este dispositivo.)

Varning!

Denna varningssymbol signalerar fara. Du befinner dig i en situation som kan leda till personskada.
Innan du utför arbete på någon utrustning måste du vara medveten om farorna med elkretsar och
känna till vanligt förfarande för att förebygga skador. (Se förklaringar av de varningar som
förekommer i denna publikation i appendix “Translated Safety Warnings” [Översatta
säkerhetsvarningar] i den installationshandbok som medföljer denna anordning.)

Acronyms and Terms
To fully understand the content of this guide, you should be familiar with the acronyms and terms listed
in this section. These terms are specific to the operation of a data cable network; more general
networking acronyms and terms can be found in Internetworking Terms and Acronyms, available on CCO
and the Documentation CD-ROM.
•

3DES—Triple Data Encryption Standard.

•

ASIC—Application Specific Integrated Circuit.

•

BPI—Baseline Privacy Interface.

•

BPI+ —Extension to the initial BPI standard with improved authentication and encryption.

•

CM—Cable modem.

•

CMTS—Cable Modem Termination System (headend).

•

CoS—Class of service.

•

CPE—Customer Premises Equipment.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

Preface
Related Documentation

•

DES—Data Encryption Standard.

•

DOCSIS 1.0—Data Over Cable Service Interface Specification.

•

DOCSIS 1.0+—Extension of the DOCSIS 1.0 standard with features that support quality of service
(QoS) options to offer better than best effort, low latency, and low jitter services.

•

Downstream—Transmission of traffic from the CMTS (headend) to the CM (cable modem).

•

IPSec—IP network security.

•

Kbps—Kilobits per second.

•

MAC—Media Access Control.

•

Mbps—Megabits per second.

•

MODEM—modulator/demodulator.

•

MSO—Multiple Systems Operator.

•

NIU/STB—Network Interface Unit/Set-Top Box.

•

PPS—Packets per second.

•

QAM—Quadrature Amplitude Modulation.

•

QoS—Quality of service.

•

QPSK—Quadrature Phase Shift Keying.

•

RF—Radio frequency.

•

SID—Service Identifier (DOCSIS MAC-level service flow identifier)

•

SM—Subscriber Modem or Spectrum Manager.

•

uBR—Universal broadband router.

•

Upstream—Transmission of traffic from CM (cable modem) to the CMTS (headend).

•

VoIP—Voice over IP.

Related Documentation
Refer to the following Cisco documents for related information. The documents can be found online at
Cisco Connection Online (CCO) or on the Documentation CD-ROM. You can also order printed copies
of most current documents.

Note

The list that follows is not all-inclusive. New documents and revisions occur frequently.

Cisco uBR924 Cable Access Router
•

Cisco uBR924 Cable Access Router Software Configuration Guide (this manual)

•

Cisco uBR924 Cable Access Router Hardware Installation Guide

•

Cisco uBR924 Cable Access Router Quick Start Guide

•

DOCSIS CPE Configurator Help

•

Release Notes for each release of Cisco IOS software for the Cisco uBR924 cable access router

Cisco uBR924 Software Configuration Guide

xii

OL-0337-05 (8/2002)

Preface
Related Documentation

Note

The Cisco uBR924 Cable Access Router Installation and Configuration Guide is still available
on CCO but has been superseded by the hardware and software guides listed above.

CMTS Hardware Installation Publications
•

Cisco uBR7200 Series Universal Broadband Router Hardware Installation Guide

•

Cisco uBR7200 Series Universal Broadband Router Software Configuration Guide

•

Cisco uBR7200 Series Universal Broadband Router Cable Modem Card Installation and
Configuration

•

Cisco uBR7200 Series Universal Broadband Router Port Adapter Installation and Configuration

•

Cisco uBR7200 Series Universal Broadband Router 550-Watt DC-Input Power Supply Replacement
Instructions

•

Cisco uBR7200 Series Universal Broadband Router Subchassis and Midplane Replacement
Instructions

•

Cisco uBR7200 Series Rack-Mount and Cable-Management Kit Installation Instructions

•

Cisco uBR7200 Series Universal Broadband Router Fan Tray Replacement Instructions

•

Cisco uBR7200 Series Universal Broadband Router Feature Enhancements

Cisco IOS Publications

Note

•

Cisco IOS Release 12.1 New Feature Documentation for feature module descriptions on Cisco IOS
Release 12.1-based releases

•

Cisco IOS Release 12.1 Configuration Guides and Command References for task and command
descriptions on Cisco IOS Release 12.1-based releases

Use the Cisco IOS Command Reference Master Index(es) to obtain document pointers for specific
software release feature sets and commands.

Configuration Editor and Network Management Publications
•

Cisco Cable Configuration Guide for information on the Cisco Network Registrar (CNR) product

•

CiscoView: Internetworking Device Monitoring and Management

•

CiscoView Incremental Installation Quick Reference Guide

•

CiscoWorks documentation for networks that use the Simple Network Management Protocol
(SNMP) to monitor Cisco uBR924 router

Subscriber Publications
•

Quick Start, Cisco uBR924 Cable Access Router Subscriber Setup

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

xiii

Preface
Obtaining Documentation

Note

Service provider and subscriber publications for other models of Cisco uBR900 Series cable access
routers are also available on CCO.

Obtaining Documentation
World Wide Web
You can access the most current Cisco documentation on the World Wide Web at http://www.cisco.com,
http://www-china.cisco.com, or http://www-europe.cisco.com.

Documentation CD-ROM
Cisco documentation and additional literature are available in a CD-ROM package, which ships with
your product. The Documentation CD-ROM is updated monthly. Therefore, it is probably more current
than printed documentation. The CD-ROM package is available as a single unit or as an annual
subscription.

Ordering Documentation
Registered CCO users can order the Documentation CD-ROM and other Cisco Product documentation
through our online Subscription Services at http://www.cisco.com/cgi-bin/subcat/kaojump.cgi.
Nonregistered CCO users can order documentation through a local account representative by calling
Cisco’s corporate headquarters (California, USA) at 408 526-4000 or, in North America, call
800 553-NETS (6387).

Obtaining Technical Assistance
Cisco provides Cisco Connection Online (CCO) as a starting point for all technical assistance. Warranty
or maintenance contract customers can use the Technical Assistance Center. All customers can submit
technical feedback on Cisco documentation using the web, e-mail, a self-addressed stamped response
card included in many printed documents, or by sending mail to Cisco.

Cisco Connection Online
Cisco continues to revolutionize how business is done on the Internet. Cisco Connection Online is the
foundation of a suite of interactive, networked services that provides immediate, open access to Cisco
information and resources at anytime, from anywhere in the world. This highly integrated Internet
application is a powerful, easy-to-use tool for doing business with Cisco.

Cisco uBR924 Software Configuration Guide

xiv

OL-0337-05 (8/2002)

Preface
Obtaining Technical Assistance

CCO’s broad range of features and services helps customers and partners to streamline business
processes and improve productivity. Through CCO, you will find information about Cisco and our
networking solutions, services, and programs. In addition, you can resolve technical issues with online
support services, download and test software packages, and order Cisco learning materials and
merchandise. Valuable online skill assessment, training, and certification programs are also available.
Customers and partners can self-register on CCO to obtain additional personalized information and
services. Registered users may order products, check on the status of an order and view benefits specific
to their relationships with Cisco.
You can access CCO in the following ways:
•

WWW: www.cisco.com

•

Telnet: cco.cisco.com

•

Modem using standard connection rates and the following terminal settings: VT100 emulation;
8 data bits; no parity; and 1 stop bit.
– From North America, call 408 526-8070
– From Europe, call 33 1 64 46 40 82

You can e-mail questions about using CCO to cco-team@cisco.com.

Technical Assistance Center
The Cisco Technical Assistance Center (TAC) is available to warranty or maintenance contract
customers who need technical assistance with a Cisco product that is under warranty or covered by a
maintenance contract.
To display the TAC web site that includes links to technical support information and software upgrades
and for requesting TAC support, use www.cisco.com/techsupport.
To contact by e-mail, use one of the following:
Language

E-mail Address

English

tac@cisco.com

Hanzi (Chinese)

chinese-tac@cisco.com

Kanji (Japanese)

japan-tac@cisco.com

Hangul (Korean)

korea-tac@cisco.com

Spanish

tac@cisco.com

Thai

thai-tac@cisco.com

In North America, TAC can be reached at 800 553-2447 or 408 526-7209. For other telephone numbers
and TAC e-mail addresses worldwide, consult the following web site:
http://www.cisco.com/warp/public/687/Directory/DirTAC.shtml.

Documentation Feedback
If you are reading Cisco product documentation on the World Wide Web, you can submit technical
comments electronically. Click Feedback in the toolbar and select Documentation. After you complete
the form, click Submit to send it to Cisco.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

Preface
Obtaining Technical Assistance

You can e-mail your comments to bug-doc@cisco.com.
To submit your comments by mail, for your convenience many documents contain a response card
behind the front cover. Otherwise, you can mail your comments to the following address:
Cisco Systems, Inc.
Document Resource Connection
170 West Tasman Drive
San Jose, CA 95134-9883
We appreciate and value your comments.

Cisco uBR924 Software Configuration Guide

xvi

OL-0337-05 (8/2002)

C H A P T E R

Overview
This chapter provides a basic understanding of the Cisco uBR924 cable access router’s software feature
sets, as well as the processes used for provisioning the router within a cable network and configuring it
for different services. This chapter contains the following sections:

Note

•

Cisco IOS Software Release Feature Sets

•

Initial Provisioning

•

Supporting Multiple Classes of Service

This manual describes the Cisco uBR924 cable access router and feature sets as they exist in Cisco IOS
Release 12.1(5)T.

Cisco IOS Software Release Feature Sets
The Cisco uBR924 cable access router supports a number of feature sets. Each feature set contains
features that provide a specific functionality, such as firewall or advanced encryption. All feature sets,
however, support base IP bridging as required by the Data Over Cable Service Interface Specification
(DOCSIS). This allows the Cisco uBR924 cable access router to transmit data traffic over the HFC cable
network.
In addition to data traffic, the images for the Cisco uBR924 cable access router enable the voice ports,
allowing the router to transmit Voice over IP (VoIP) and fax traffic over the cable network and Internet.
Voice and data traffic can be transmitted simultaneously, but real-time traffic such as voice calls requires
different handling than data traffic—data traffic can be sent on a “best-effort” basis because it can accept
some loss or delay in the transmission of packets, but such losses and delays are unacceptable for voice
calls.
For this reason, the Cisco uBR924 cable access router supports the DOCSIS Quality of Service (QoS)
enhancements that give higher priority to IP packets containing voice traffic. This ensures that real-time
traffic is delivered more reliably than “best-effort” data traffic.
The telephones and fax machines connected to the Cisco uBR924 router can route their calls over the
Internet using either the H.323v2 (Gateway/Gatekeeper) or Simple Gateway Control Protocol (SGCP)
voice control protocols. Depending on the protocol used and the level of support provided by the service
provider, these calls can be made either to other VoIP devices or to phones connected on the regular telco
network.
The following Cisco IOS Release 12.1 images support both data and voice traffic, in addition to the other
feature sets that are listed:

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

1-1

Chapter 1

Overview

Cisco IOS Software Release Feature Sets

Note

•

Base IP DOCSIS-Compliant Bridging—Provides full DOCSIS 1.0-compliant cable modem
support for customers who want a basic high-speed connection to the Internet. This is the default
software image for the Cisco uBR924 cable access router in Cisco IOS Release 12.0; in Cisco IOS
Release 12.1 and later, this image is superseded by the Home Office (Easy IP) image.

•

Home Office (Easy IP)—Provides a high-speed DOCSIS connection to the Internet, along with
server functions that simplify the administration of IP addresses. In addition to simplifying network
management, this allows the Cisco uBR924 router to connect multiple computers to the Internet
through the cable interface. This is the default software image for the Cisco uBR924 cable access
router in Cisco IOS Release 12.1.

•

Value Telecommuter —Adds IPsec encryption and layer 2 tunneling support to the functions
provided by the Home Office (Easy IP) image. This allows businesses to establish secure high-speed
Internet connections between employees’ homes and the office local area network (LAN). This gives
the employees’ computers the same connectivity they would have if they were directly connected to
the office network.

•

Performance Telecommuter —Adds advanced IPsec encryption to the functions provided by the
Value Telecommuter image, enabling high-speed and high-security Internet connections between
employees’ homes and the office LAN.

•

Value Small and Branch Office—Adds IPsec encryption and the Cisco Secure Integrated Software
(firewall) feature set to the functions provided by the Home Office image. This allows customers to
establish secure connections across the Internet; this feature set also protects the office network from
intrusion and interference while preserving the permanent high-speed access to the Internet.

•

Performance Small and Branch Office—Adds advanced IPsec encryption to the functions
provided by the Value Small and Branch Office image. This allows customers to establish
high-security connections across the Internet; this feature set also protects the office network from
intrusion and interference while preserving the permanent high-speed access to the Internet.

Starting with Cisco IOS Release 12.1(1), the Cisco uBR924 cable access router supports fewer software
images than previous releases (which supported 14 separate images). The new simplified set of software
images are a superset of the images supported in the previous releases, allowing for an easy upgrade path
from Release 12.0 to Release 12.1.
The following sections describe the feature sets in each of these categories. Descriptions of the features
themselves are in the section “Feature Descriptions” section on page 1-5.

Note

Not all Cisco IOS software releases and images support all features. In particular, early deployment (ED)
releases might contain a limited number of images that support a subset of feature sets and images. ED
releases might also support images and feature sets that are not listed here—see the Release notes for
each Release for complete details on images and feature support.

Base IP DOCSIS-Compliant Bridging
The Base IP Bridging feature set includes DOCSIS-compliant bridging and DOCSIS Baseline Privacy
Interface (BPI) encryption. This is the default feature set for the Cisco uBR924 cable access router in
Cisco IOS Release 12.0 and allows the router to function as a DOCSIS 1.0 cable modem that can
interoperate with any DOCSIS-qualified Cable Modem Termination System (CMTS). It provides basic
high-speed Internet connectivity for customers who want to connect a small number of computers to the
cable network.

Cisco uBR924 Software Configuration Guide

1-2

OL-0337-05 (8/2002)

Chapter 1

Overview
Cisco IOS Software Release Feature Sets

DOCSIS-compliant bridging (also referred to as “plug-and-play” bridging) is the default configuration
for the Cisco uBR924 router. In this mode, the router automatically does the following at power-on and
system reset:

Note

•

Acquires temporary downstream and upstream channels

•

Finds the appropriate Time of Day (ToD), Trivial File Transfer Protocol (TFTP), and Dynamic Host
Configuration Protocol Server (DHCP) servers

•

Gets the current time of day from the ToD server

•

Obtains an IP address from the DHCP server

•

Downloads a DOCSIS configuration file from the TFTP server

•

Configures itself for its permanent downstream and upstream channels

•

Obtains other DHCP parameters to work in bridging mode

•

Optionally downloads a Cisco IOS image and Cisco IOS configuration file if specified in the
DOCSIS configuration file

•

Establishes a BPI session (if enabled on both the router and CMTS)

The Base IP Bridging feature set is the default image for the Cisco uBR924 cable access router in
Cisco IOS Release 12.0. It is not available as a separate image in Cisco IOS Release 12.1 because is
incorporated in all other available images.
In DOCSIS-compliant bridging mode, the Cisco uBR924 cable access router acts as a transparent bridge
for one or more customer premises equipment (CPE) devices. The maximum number of CPE devices
depends on the Cisco IOS Release being used:

Note

•

3 CPE devices using Cisco IOS Release 12.0(4) XI1

•

254 CPE devices using Cisco IOS Release 12.0(5)T or later images

The maximum number of CPE devices also depends on the value of the “MAX CPE” field in the
DOCSIS configuration file. The MAX CPE field defaults to one CPE device unless set otherwise. In this
situation, the Cisco uBR924 router can connect only one computer to the cable network, regardless of
the Cisco IOS Release being used.

Home Office (Easy IP)
The Home Office feature set provides high-speed Internet connectivity for customers who have a small
home network. In addition to full DOCSIS 1.0 support (see Base IP DOCSIS-Compliant Bridging), the
Home Office feature set provides the Easy IP set of features that simplifies the administration of IP
addresses in a cable network.
This feature set supports intelligent Dynamic Host Configuration Protocol Server (DHCP) functions,
such as DHCP Relay Agent and DHCP Client functionality. It also supports Network Address
Translation and Port Address Translation (NAT/PAT).
The DHCP features provide intelligence and flexibility in the handling and distribution of IP addresses
for the PCs and other CPE devices being connected to the cable network. The NAT/PAT features allow
the customer to use private IP addresses on the local network, while still maintaining connectivity to the
Internet.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

1-3

Chapter 1

Overview

Cisco IOS Software Release Feature Sets

Value Telecommuter
In addition to full DOCSIS 1.0 support and the Home Office (Easy IP) feature set, the Value
Telecommuter feature set supports 56-bit IPsec encryption and the Layer 2 Tunneling Protocol (L2TP).
These additional features allow employees to establish secure high-speed Internet connections between
the employees’ homes and the business’ local area network (LAN).
IPsec encryption provides robust authentication and encryption of IP packets so that sensitive
information can be securely transmitted over unprotected networks such as the Internet. The standard
56-bit Data Encryption Standard (DES) encryption provides sufficient security for most applications.

Note

IPsec encryption is in addition to BPI encryption. BPI encryption is done only on the traffic between the
Cisco uBR924 router and the CMTS, not on traffic sent over the Internet. IPsec encryption, however, is
end-to-end encryption, protecting traffic sent across the Internet from one host to another.
L2TP is an extension of the Point-to-Point Protocol (PPP) that allows computers on different physical
networks to interoperate as if they were on the same local network. L2TP and IPsec encryption are often
used to create virtual private networks (VPNs).

Note

The Cisco uBR924 cable access router does not support the L2TP feature in Cisco IOS Release 12.1(3)T
and later releases.

Performance Telecommuter
The Performance Telecommuter feature set includes all of the features found in the Value Telecommuter
image, but adds 168-bit IPsec Triple Data Encryption Standard (3DES) encryption. The advanced IPsec
encryption provides a higher-level of security to protect very sensitive information, such as medical and
banking records.

Value Small and Branch Office
The Value Small and Branch Office feature set adds the Cisco Secure Integrated Software firewall
feature to the DOCSIS 1.0 support, Home Office (Easy IP), and 56-bit IPsec encryption feature sets,
providing a wide range of security features for the Cisco uBR924 router. The Cisco uBR924 router uses
the firewall capability to protect the computers in the local office network from threats such as denial of
service attacks and destructive Java applets. The router can also provide real-time alerts of such attacks.
IPsec encryption provides robust authentication and encryption of IP packets so that sensitive
information can be securely transmitted over unprotected networks such as the Internet. The standard
56-bit Data Encryption Standard (DES) encryption provides sufficient security for most applications.

Note

The Cisco uBR924 cable access router does not support the L2TP feature in Cisco IOS Release 12.1(3)T
and later releases.

Cisco uBR924 Software Configuration Guide

1-4

OL-0337-05 (8/2002)

Chapter 1

Overview
Cisco IOS Software Release Feature Sets

Performance Small and Branch Office
The Performance Small and Branch Office feature set includes all of the features found in the Value
Small and Branch Office image, but adds 168-bit IPsec Triple Data Encryption Standard (3DES)
encryption. The advanced IPsec encryption provides a higher-level of security to protect very sensitive
information, such as medical and banking records.

Feature Descriptions
This section describes the particular features that are contained in the feature sets supported by the
Cisco uBR924 cable access router. See the Release Notes for any particular release for information on
which features are contained in a particular Cisco IOS image.

Cable Monitor Web Diagnostics Tool
The Cable Monitor is a web-based diagnostic tool to display the current status and configuration of the
Cisco uBR924 router. The Cable Monitor can also be used when the cable network is down, providing
an easy way for subscribers to provide necessary information to service technicians and troubleshooters.
The Cable Monitor is introduced in Cisco IOS Release 12.1(1)T and is described in detail in
Appendix B, “Using the Cable Monitor Tool.”

Cisco Cable Clock Card Support
The Cisco uBR924 router automatically supports the use of the Cisco Cable Clock Card on the
Cisco uBR7246 VXR universal broadband router. The National Clock Card enables the Cisco uBR7246
VXR router to use a primary and secondary external clock derived from a Stratum 1 source. This
provides a high quality clocking signal that minimizes jitter and other timing problems that can interfere
with real-time traffic such as VoIP calls.
This feature is introduced in Cisco IOS Release 12.1(1)T.

Cisco IOS Firewall
The Cisco IOS Firewall feature set provides firewall-specific security features to the
Cisco uBR924 router. When this feature is enabled, the Cisco uBR924 router acts as a buffer between
the Internet and other public networks and the private network that is connected to the Cisco uBR924
router. Security is provided by access lists, as well as by examining incoming traffic for suspicious
activity.
The security features include the following:
•

Authentication proxy services to intelligently apply specific security policies on a per-user basis
without impacting performance.

•

Checking packet headers and dropping suspicious packets to detect and prevent denial of service
attacks, such as ICMP and UDP echo packet flooding, SYN packet flooding, half-open or other
unusual TCP connections, and deliberate mis-fragmentation of IP packets.

•

Context-Based Access Control (CBAC) which gives internal-to-the-firewall users secure,
per-application-based traffic control across the Internet/Intranet. This includes protection against
Simple Mail Transfer Protocol (SMTP) attacks, one of the most common attacks against computers
connected to the Internet.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

1-5

Chapter 1

Overview

Cisco IOS Software Release Feature Sets

•

Dynamic port mapping to allow network applications with well-known port assignments to use
customized port numbers. This can be done on a host-by-host basis or for an entire subnet, providing
a large degree of control over which users can access different applications.

•

Intrusion Detection System (IDS) that recognizes the signatures of 59 common attack profiles.
When an intrusion is detected, IDS can perform a number of actions: send an alarm to a syslog server
or to NetRanger Director, drop the packet, or reset the TCP connection.

•

Java blocking to protect against destructive Java applets. Applets can be allowed from only known
and trusted sources or blocked completely.

•

Real time and configurable alerts and audit trail capabilities to record and timestamp source and
destination hosts.

•

Support for a broad range of commonly used protocols, including H.323 and NetMeeting, FTP,
HTTP, MS Netshow, RPC, SMTP, SQL*Net, and TFTP.

•

User-configurable audit rules, real-time alerts, and audit-trail logs.

This feature is introduced in Cisco IOS Release 12.0(5)T and is enhanced with additional capabilities in
12.0(7)T.

Note

For general information about these features, see the description of the Cisco IOS Firewall Feature Set
in the Cisco Product Catalog. For detailed information, see the Cisco IOS Firewall Feature Set
documentation set, as well as the sections on Traffic Filtering and Firewalls in the Security Configuration
Guide and Security Command Reference (available on the Documentation CD-ROM and CCO).

DOCSIS-Compliant Bridging
DOCSIS-compliant bridging allows the Cisco uBR924 cable access router to operate as a DOCSIS 1.0
cable modem, so that it can interoperate with any DOCSIS-qualified CMTS. This is the default mode of
operation for the Cisco uBR924 router.
This feature is introduced in Cisco IOS Software Release 12.0(4)XI1.

DOCSIS Baseline Privacy Interface
The DOCSIS Baseline Privacy Interface (BPI) feature is based on the DOCSIS BPI Specification
(SP-BPI-I02-990319 or later revision). It provides data privacy across the Hybrid Fiber-Coaxial (HFC)
network by encrypting traffic flows between the Cisco uBR924 router and the cable operator’s CMTS.
This feature is introduced in Cisco IOS Software Release 12.0(5)T.

Dynamic Host Configuration Protocol Server
The DHCP server on the Cisco uBR924 router includes both Intelligent DHCP Relay and DHCP Client
functionality. A DHCP Relay Agent is any host that forwards DHCP packets between clients and
servers—this enables the client and server to reside on separate subnets. If the Cisco IOS DHCP server
cannot satisfy a DHCP request from its own database, it can forward the DHCP request to one or more
secondary DHCP servers defined by the network administrator.
This feature is introduced in Cisco IOS Release 12.0(4)XI.

Cisco uBR924 Software Configuration Guide

1-6

OL-0337-05 (8/2002)

Chapter 1

Overview
Cisco IOS Software Release Feature Sets

Dynamic Host Configuration Protocol Proxy Support
The DHCP Proxy Support feature is useful in two situations:
•

When the Cisco uBR924 cable access router is configured for routing mode, an IP address must be
assigned to its Ethernet interface. The DHCP Proxy Support feature allows an external DHCP server
to assign an IP address to the Ethernet interface, as opposed to having to assign it manually with the
appropriate CLI commands.

•

When network address translation (NAT) is used, an inside global address pool must be created on
the Ethernet interface. The DHCP Proxy Support feature allows a DHCP server to assign an IP
address that automatically creates the NAT address pool, as opposed to manually specifying a static
IP address with the appropriate CLI commands.

When configured for DHCP Proxy Support, during startup the Cisco uBR924 cable access router sends
a proxy DHCP request to the DHCP server using the Ethernet interface’s MAC address. The DHCP
server replies with a second IP address that the router assigns to either the Ethernet interface or to the
NAT pool, depending on which option was specified.
This feature is introduced in Cisco IOS Release 12.1(1)T and is described in detail in Appendix D, “New
and Changed Commands Reference.”

Enhanced IP Bridging
The Cisco uBR924 cable access router can transparently bridge traffic between its cable interface and
its four RJ-45 hub ports with 10BaseT Ethernet connectivity. Up to four computers can be directly
connected to these hub ports. Additional computers can be connected to the Cisco uBR924 router by
connecting an Ethernet hub to one of the router’s four ports; the hub, in turn, can be connected to
additional computers or devices at the site.
A maximum of 3 devices can be bridged using Cisco IOS Release 12.0(4)XI images. A maximum of 254
devices can be bridged using Cisco IOS Release 12.0(5)T or higher images. (No limit exists when the
Cisco uBR924 cable access router is operating in routing mode.)
This feature is introduced in Cisco IOS Release 12.0(5)T.

Note

Ecosystem Gatekeeper Interoperability Enhancements
The Ecosystem Gatekeeper Interoperability Enhancements feature improves the ability of voice
gateways to move between gatekeepers upon a failure or an outage. Currently, gateways can be
configured to switch from their primary gatekeeper to an alternate gatekeeper if a failure or outage
occurs.
However, moving gateways from one gatekeeper to another can create an imbalance in the number of
gateways registered to each gatekeeper. The Ecosystem Gatekeeper Interoperability Enhancements
feature helps to restore the balance by moving some of the gateways back to their proper gatekeepers
after the outage has been corrected.
The Cisco uBR924 cable access router automatically supports this feature when acting as an H.323v2
voice gateway. This feature has been implemented in two phases:

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

1-7

Chapter 1

Overview

Cisco IOS Software Release Feature Sets

•

Phase 1—Adds support for the alternate gatekeeper field (altGKInfo) to the gatekeeper rejection
(GRJ) and registration rejection (RRJ) messages. This allows a gateway to move between
gatekeepers during the gatekeeper request (GRQ) and registration request (RRQ) phases.

•

Phase 2—Adds support for the alternate gatekeeper field (altGKInfo) to the admission rejection
(ARJ) message. This allows a gateway to move between gatekeepers during the admission request
(ARQ) phase.

Phase 1 of this feature is introduced in Cisco IOS Release 12.1(1)T. Phase 2 is introduced in Cisco IOS
Release 12.1(2)T.

Note

For more information on this feature, see the Ecosystem Gatekeeper Interoperability Enhancements,
Phase 2 feature module, available on CCO and the Documentation CD-ROM.

Fax over IP
Fax over IP is a form of VoIP support that supports the unique characteristics of fax transmissions. When
using a voice-enabled image, the two voice ports on the Cisco uBR924 router can be connected to either
fax machines or voice telephones, allowing fax traffic to be sent as VoIP traffic.
This feature is introduced in Cisco IOS Software Release 12.0(5)T.

H.323v2 (Gateway/Gatekeeper)
The Cisco uBR924 cable access router can support VoIP traffic as an H.323v2 gateway. The H.323v2
protocol maps an IP address to an E.164 telephone number, allowing VoIP calls to terminate either on
other VoIP devices or on devices in the regular telco network. The H.323v2 protocol uses a dial plan and
mapper on a server located at the CMTS or elsewhere to perform this mapping, which can be done either
statically or dynamically, depending on the version of Cisco IOS software being used.
•

In Cisco IOS Release 12.0(4)XI1 or higher images, the service provider can configure the IP
addresses statically using the voip dial peer group command. The service provider can also
configure the telephone numbers attached to the Cisco uBR924 cable access router by configuring
the IP addresses statically using the CLI pots port command.

•

In Cisco IOS Release 12.0(5)T or higher images, the service provider can obtain IP addresses
dynamically from a Cisco gatekeeper using Registration, Admission, and Status (RAS). The service
provider can also dynamically obtain telephone IP addresses using Cisco Network Registrar (CNR).

•

Cisco IOS Release 12.1(1)T adds a number of H.323v2 features:
– Fast Connect—This H.323v2 feature allows connections for the most common types of calls to

be created without establishing a separate H.245 control channel.
– H.245 Tunneling—Supports two H.245 features during a call without having to establish an

H.245 channel:
DTMF digit relay—Dual-tone multifrequency (DTMF) tones are often used during a voice call
to convey information, such as entering an account number voicemail commands. Certain forms
of compression (such as G.729) might interfere with these tones, so they must be transmitted
“out of band,” separated from the encoded voice stream.
Hookflash relay—Many types of PBX and telephone switches give a special meaning to a
hookflash (quickly depressing and releasing the hook on your telephone). Because this creates
a voltage change that cannot be transmitted across an IP network, the H.323 protocol can send
an H.245 User Input Indication message to convey the hookflash to the remote end.

Cisco uBR924 Software Configuration Guide

1-8

OL-0337-05 (8/2002)

Chapter 1

Overview
Cisco IOS Software Release Feature Sets

For information about these features, see H.323 Version 2 Support, available on CCO at
http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120t/120t5.
•

Cisco IOS Release 12.1(2)T adds H.323 support for virtual interfaces, allowing the use of the
Ethernet interface’s IP address for outgoing H.323 traffic, which includes H.225, H.245, and RAS
messages. This enables the use of VoIP traffic over VPN solutions. See the h323-gateway voip bind
srcaddr command for more information. In addition, the value of the H.225 TCP connection
timeout timer is configurable.

Support for H.323 is introduced in Cisco IOS Release 12.0(4)XI1 and enhanced with support for
H.323v2 in Cisco IOS Release 12.0(5)T. Additional H.323v2 features are added in
Cisco IOS Release 12.1(1)T and Cisco IOS Release 12.1(2)T.

IP Address Negotiation
Cisco IOS Release 12.1(4)T for Cisco uBR900 series cable access routers adds support for the
ip address docsis command on the cable interface. Previous releases used the ip address dhcp and ip
address negotiated command for this purpose, but these commands cannot be used on cable interfaces.

IPsec Network Security
IPsec network security provides robust authentications and encryption of IP packets. IPsec is a
framework of open standards developed by the Internet Engineering Task Force (IETF) for the secure
transmission of sensitive information over unprotected networks such as the Internet. IPsec acts at the
network layer (Layer 3), protecting and authenticating IP packets between participating IPsec devices
(“peers”) such as the Cisco uBR924 cable access router.
Unlike BPI encryption, which protects traffic only on the cable interface between the cable modem and
CMTS, IPsec encryption provides end-to-end protection across open networks such as the Internet. Two
levels of encryption—56-bit and 168-bit—are available, depending on the software image being used.
This feature is introduced in Cisco IOS Release 12.0(5)T.

Note

Layer 2 Tunneling Protocol
Layer 2 Tunneling Protocol (L2TP) is an IETF standard that combines the best features of two existing
tunneling protocols: Cisco’s Layer 2 Forwarding (L2F) and Microsoft’s Point-to-Point Tunneling
Protocol (PPTP). L2TP extends the Point-to-Point Protocol (PPP) to provide a secure connection across
an open network and is an important component for virtual private networks (VPNs).
This feature is introduced in Cisco IOS Release 12.0(5)T and is supported through Cisco IOS
Release 12.1(2)T. L2TP is not supported in Cisco IOS Release 12.1(3)T or later images.

Note

Cisco IOS Release 12.1(5)T, 12.2(2), or greater is required to support GRE IP tunnels.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

1-9

Chapter 1

Overview

Cisco IOS Software Release Feature Sets

Media Gateway Control Protocol V12.1.3T
Cisco IOS Release 12.1(3)T for the Cisco uBR924 cable access router supports version 0.1 of the Media
Gateway Control Protocol (MGCP), a proposed IETF voice control protocol that is intended to
eventually supersede the existing SCGP 1.1 protocol. The MGCP 0.1 and SGCP 1.1 protocols have been
merged on the Cisco uBR924 router so that the router can respond efficiently to either protocol.
The Cisco uBR924 cable access router functions as a Residential Gateway (RGW), providing an
interface between analog FXS phone or fax systems and the Voice over IP (VoIP) network. The RGW
uses a Trunking Gateway (TGW) to contact the call agent, which in turn provides access to the public
telephone switched network (PTSN).
The Cisco uBR924 cable access router supports both call waiting and caller ID when using either MGCP
or SGCP for call control. Each of the two voice ports on the Cisco uBR924 router can be configured with
the IP address for a default call agent. SNMP management of both the MGCP and SNMP protocols is
provided by a single MIB (XGCP-MIB).

Note

This feature is described in detail in the Media Gateway Control Protocol Version 12.1.3T feature
module, available on CCO and the Documentation CD-ROM.

NetRanger Support—Cisco IOS Intrusion Detection
The Cisco uBR924 router supports NetRanger, which is an Intrusion Detection System (IDS) composed
of three parts:
•

A management console (director) that displays alarms and manages the sensors.

•

One or more sensors that monitor traffic, comparing it to a list of known signatures to detect misuse
of the network. When a signature is matched, the sensor can take certain actions, such as resetting
a session, dropping traffic, or sending alarms to the director.

•

Automated report generation of standardized and customizable reports.

This feature is introduced in Cisco IOS Release 12.0(7)T.

Network Address Translation and Port Address Translation
Network address translation (NAT) and port address translation (PAT) frees a private network from the
requirement of having a worldwide unique IP address for every computer connected to the Internet.
Instead, the Cisco uBR924 router translates the IP addresses used on the private network into a global
IP address that can be used on the Internet. One IP address can be used for multiple computers because
the Cisco uBR924 router uses a unique port address to identify individual computers on the private
network.
This feature is introduced in Cisco IOS Release 12.0(4)XI1.

Network Address Translation Support for NetMeeting Directory (Internet Locator Service)
Microsoft NetMeeting is a Windows-based application that allows users to interact and collaborate using
their PCs over the Internet or an intranet. Previously, users had to know the IP addresses of other users’
PCs to make a connection. The NetMeeting Directory (ILS) feature enables the users to connect by using
the names that are in the directory built into the NetMeeting application. Users no longer need to know
the destination IP addresses to make a connection.
This feature is introduced in Cisco IOS Release 12.1(5)T.

Cisco uBR924 Software Configuration Guide

1-10

OL-0337-05 (8/2002)

Chapter 1

Overview
Cisco IOS Software Release Feature Sets

Quality of Service
Quality of service (QoS) is a set of features that identify different types of traffic on a network so that
certain types of traffic can be given higher priority than other types of traffic that have only a “best
effort” attempt at delivery. This feature is especially important for real-time traffic, such as voice traffic,
where delays would have a serious impact on the traffic’s usefulness.
Depending on the software image used, the Cisco uBR924 cable access router supports the following
QoS features:
•

Resource Reservation Protocol (RSVP)—Layer 3 QoS signaling protocol that provides for the
reservation of resources across an IP network. Applications running on IP end systems can use
RSVP to indicate to other nodes the nature (such as bandwidth, jitter, and maximum burst) of the
packet streams they want to receive. RSVP is defined in RFC 2205.

•

Distributed Open Signaling Architecture/Session Initialization Protocol (DOSA/SIP)—Call flow
protocol that uses the AT&T VoIP over cable architecture.

•

DOSA/QoS—Quality of service mechanism used on the AT&T VoIP over cable architecture.

•

Committed Access Rate (CAR)—Specifies the minimum bandwidth that is guaranteed for a
particular type of traffic.

•

Multi-Service Identifier (SID)—Allows a service provider to offer different classes of service to its
customers, so that different types of traffic can be given different priorities of service.

•

Traffic Shaping—Process of delaying packets that would otherwise be dropped because they exceed
the rate limit on a particular cable modem’s upstream. The Cisco uBR924 router buffers the
upstream packet until bandwidth is available. This is particularly important with TCP/IP traffic
because when a TCP packet is dropped, the destination device automatically drops all other packets
it currently contains in its receive buffer and then requests the retransmission of those packets. This
retransmission of packets increases the congestion that already exists in this situation, drastically
reducing overall throughput.

These features are introduced in Cisco IOS Release 12.0(7)T and enhanced in subsequent releases.

Quality of Service—DOCSIS 1.0+ Extensions
In addition to the other QoS features, DOCSIS 1.1 supports a number of features that are required for
the delivery of high quality voice traffic. To use these features before the DOCSIS 1.1 specification is
finalized, Cisco has created the DOCSIS 1.0+ extensions that contain the most important of these
features.
•

Concatenation—DOCSIS concatenation combines multiple upstream packets into one packet to
reduce packet overhead and overall latency, as well as increase transmission efficiency. Using
concatenation, a DOCSIS cable modem makes only one bandwidth request for multiple packets, as
opposed to making a different bandwidth request for each individual packet; this technique is
especially effective for bursty real-time traffic, such as voice calls.

•

Dynamic Multi-SID Assignment—To give priority to voice traffic, the Cisco uBR924 router assigns
a different SID to each voice port. Without the DOCSIS 1.0+ extensions, the router creates these
SIDs during the provisioning process, and the SIDs remain in effect until the router is rebooted with
a different configuration. As part of this process, a minimum guaranteed bandwidth is permanently
allocated to the voice ports; this bandwidth is reserved to the voice ports even if no calls are being
made.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

1-11

Chapter 1

Overview

Cisco IOS Software Release Feature Sets

To avoid potentially wasting bandwidth in this manner, the DOCSIS 1.0+ extensions support the
dynamic creation of multiple SIDs. New MAC messages dynamically add, delete, and modify SIDs
when needed. When a phone connected to the router is taken off-hook, the Cisco uBR924 router
creates a SID that has the QoS parameters needed for that particular voice call. When the call
terminates, the router deletes the SID, releasing its bandwidth for use elsewhere.
The DOCSIS 1.0+ features are introduced in Cisco IOS Software Release 12.0(7)XR and 12.1(1)T.

Note

Both the Cisco uBR924 cable access router and the CMTS router must support the dynamic multi-SID
and concatenation features for them to be used on the cable network. If you are using the Cisco uBR7200
series universal broadband router as the CMTS, Cisco IOS Release 12.0(7)XR, Release 12.1(1)T, or
later is required on both the Cisco uBR924 and Cisco uBR7200 series routers to use these features.

Routing Information Protocol Version 2
When configured for routing mode, the Cisco uBR924 cable access router defaults to using the Routing
Information Protocol Version 2 (RIPv2). In routing mode the Cisco uBR924 router automatically
configures itself to use the headend’s IP address as its IP default gateway. This allows the
Cisco uBR924 router to send packets not intended for the Ethernet interface to the headend.
RIPv2 routing is useful for small internetworks because it optimizes Network Interface Center
(NIC)-assigned IP addresses by defining Variable-Length Subnet Masks (VLSMs) for network
addresses, and it allows Classless Interdomain Routing (CIDR) addressing schema.
This feature is introduced in Cisco IOS Release 12.0(4)XI1.

Note

The Cisco uBR924 cable access router supports only static routes and the RIPv2 routing protocol.

Secure Shell Version 1
The Cisco uBR924 router supports the Secure Shell (SSH) Version 1 protocol, which allows network
administrators to make a secure Telnet connection with the router. SSH provides for authentication and
encryption at the application layer, providing a secure connection even when BPI or IPsec authentication
and encryption are not used at the network layer.
By default, the SSH feature uses 56-bit DES encryption. Higher security 168-bit 3DES encryption is
available when using Cisco IOS images that support 3DES IPsec encryption. (The SSH server and client
must support the same level of encryption.)
SSH server support is introduced in Cisco IOS Release 12.1(1)T. SSH client support is introduced in
Cisco IOS Release 12.1(3)T.

Note

For configuration and other information, see the Secure Shell Version 1 Client feature module, available
on CCO and the Documentation CD-ROM.

Simple Gateway Control Protocol
The Simple Gateway Control Protocol (SGCP) provides for control call setup and teardown for VoIP
calls made through the Internet or a local Intranet. SGCP uses call control agents to communicate with
the voice gateways, allowing customers to create a distributed system that enhances performance,
reliability, and scalability while still appearing as a single VoIP gateway to external clients.

Cisco uBR924 Software Configuration Guide

1-12

OL-0337-05 (8/2002)

Chapter 1

Overview
Cisco IOS Software Release Feature Sets

SGCP can preserve Signaling System 7 (SS7) style call control information, as well as additional
network information, such as routing information and authentication, authorization, and accounting
(AAA) security information. SGCP allows voice calls to be originate and terminate on the Internet, as
well as allowing one end to terminate on the Internet and the other to terminate on a telephone or PBX
on the Public Switched Telephone Network (PSTN).
The Cisco uBR924 cable access router functions as an SGCP residential gateway (RGW), not as the
trunking gateway (TGW), which controls the telephone call.

Note

The Cisco uBR924 router supports both H.323 and SGCP call control, but only one method can be active
at a time.
This feature is introduced in Cisco IOS Release 12.0(5)T and enhanced in Release 12.0(7)T. In
Cisco IOS Release 12.1(3)T, this feature is merged with the Media Gateway Control Protocol V12.1.3T
feature, providing simultaneous support for both SGCP and MGCP.

Triple Data Encryption Standard
The Data Encryption Standard (DES) is a standard cryptographic algorithm developed by the United
States National Bureau of Standards. The Triple DES (3DES) standard increases the security from the
standard 56-bit IPsec encryption to 168-bit encryption, providing a level of security that is suitable for
highly sensitive and confidential information such as financial transactions and medical records.
This feature is introduced in Cisco IOS Release 12.0(5)T.

Note

Cisco IOS Release 12.1(5)T, 12.2(2), or greater is required to support GRE IP tunnels.

VPN IPsec Enhancement—Dynamic Crypto Map
The crypto dynamic-map command is part of the Cisco Secure PIX firewall and IPsec network security
feature. The crypto dynamic-map command creates dynamic crypto maps, which are policy templates
used when processing negotiation requests for new security associations from a remote IPsec peer. This
allows you to negotiate a session even if you do not know all of the remote peer’s crypto map parameters
(such as the peer’s IP address); in particular, this allows you to accept requests for new security
associations from previously unknown peers, while still requiring the peer to complete the proper
ISAKMP (IKE) authentication.
When the firewall receives a negotiation request via IKE from another IPsec peer, the request is
examined to see if it matches a crypto map entry. If the negotiation does not match any explicit crypto
map entry, it will be rejected unless the crypto map set includes a reference to a dynamic crypto map.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

1-13

Chapter 1

Overview

Initial Provisioning

If the firewall accepts the peer’s request, it installs a temporary crypto map entry when it installs the new
IPsec security associations. This entry is filled in with the results of the negotiation. At this point, the
firewall performs normal processing, using this temporary crypto map entry as a normal entry, and even
requests new security associations if the current ones are expiring (based on the policy specified in the
temporary crypto map entry). After all of the corresponding security associations expire, the temporary
crypto map entry is removed.
The crypto dynamic-map global configuration command supports a number of options, but the only
required option is the transform-set. The other parameters are optional, depending on the needs of your
network.
This feature is introduced in Cisco IOS Release 12.0(7)T.

Note

Dynamic crypto map sets are not used for initiating IPsec security associations. However, they are used
for determining whether or not traffic should be protected.

Initial Provisioning
The Cisco uBR924 cable access router typically ships from the Cisco factory ready to work in the Base
IP DOCSIS-Compliant Bridging data-only mode. However, before router can transmit either data or
voice traffic, the CMTS at the headend must properly provision the router as follows:
•

The appropriate service must be purchased from the service provider. If certain features, such as
voice support or advanced encryption, are desired, a license for the appropriate Cisco IOS software
image must also be purchased.

•

The service provider must create a DOCSIS configuration file for the Cisco uBR924 router. This file
must be stored on a TFTP server—each router could have its own unique DOCSIS configuration file,
or the same file could be used for multiple routers, depending on the needs of the subscribers.

•

When the router is first brought online, the CMTS at the headend downloads the DOCSIS
configuration file to the router. This file is a binary file that configures the router for the appropriate
level of services and that sets other parameters as needed.

•

At this point the router is completely configured for the basic DOCSIS bridging mode, but when
additional features are required, the DOCSIS configuration file specifies that the CMTS should
download a second Cisco IOS image to the router. For example, to enable Triple DES encryption on
the Cisco uBR924 router, a Cisco IOS image with 3DES IPsec support must be downloaded to the
router. (The service provider can also preload the router with this image at the warehouse to speed
up the router’s initialization and boot time.)

•

Finally, any additional configuration on the router must be done. This can be done in the following
ways:
– When using Cisco IOS Release 12.1(1)T or greater, CLI commands can be embedded in the

DOCSIS configuration file, using the Vendor Specific Information Field (subtype 131).
– The router can download a Cisco IOS configuration file from a host workstation specified by

the DOCSIS configuration file. The Cisco IOS configuration file is an ASCII text file that
contains the Cisco IOS commands needed to configure the router.
– A system administrator can manually configure the router by giving Cisco IOS commands at the

router’s CLI interface. This can be done either locally by connecting to the router’s RJ-45
console port or remotely by establishing a Telnet connection with the router.

Cisco uBR924 Software Configuration Guide

1-14

OL-0337-05 (8/2002)

Chapter 1

Overview
Supporting Multiple Classes of Service

Note

The CMTS typically downloads the DOCSIS configuration file, Cisco IOS image (if needed), and
Cisco IOS configuration file (if needed) only once when the router is initially brought online. However,
a new configuration file or image can be downloaded whenever necessary, such as when the cable service
offers new services or when subscribers upgrade their services.
To ensure that subscribers obtain the exact services they have ordered, the Cisco uBR924 cable access
router arrives from the Cisco factory with a unique identifier (UID) that consists of a serial number and
media access control (MAC) address. These factory-assigned values are on a label at the bottom of the
router; for convenience, these values are also in a barcode label that can be scanned in for easy entry into
the service provider’s provisioning and billing system.
Using the MAC address of the router as the key, the CMTS downloads the DOCSIS configuration file
and Cisco IOS image that will provide the services this particular subscriber has purchased. Service
technicians at the headend typically create a number of standard configuration files to match the range
of services offered by the provider; these configuration files can be created manually or with tools that
Cisco Systems provides for this purpose.

Note

For a more detailed description of the provisioning process, see the Cisco uBR924 Cable Access Router
Hardware Installation Guide, available on CCO and the Documentation CD-ROM.

Supporting Multiple Classes of Service
In data-only mode, the Cisco uBR924 cable access router typically uses only one class of service (CoS)
profile that provides for best-effort delivery of data traffic. In data and voice mode, however, multiple
CoS profiles are required so that the real-time voice traffic can be given a higher priority than normal
data traffic. This allows voice traffic to be delivered in a timely manner by delaying transmission of data
traffic in a way that does not degrade the overall quality of service (QoS).

DOCSIS 1.0 Static Profiles
In a DOCSIS 1.0 network, the multiple CoS profiles must be created at the time the Cisco uBR924 router
is registered, using the CoS parameters in the DOCSIS configuration file. To support voice services in a
DOCSIS 1.0 environment, the service provider typically specifies a primary CoS profile for best-effort
data and second CoS profiles for voice and fax traffic.
The router requests the multiple profiles in a registration request message sent to the CMTS. In response,
the CMTS assigns a Service Identifier (SID) for each CoS profile. The first SID assigned is the primary
SID that is used for best effort data traffic as well as for the handling of MAC and maintenance messages.
The other SIDs are secondary SIDs used for voice and fax traffic. These SID assignments remain in
effect until the modem resets and reregisters itself using a different configuration.

DOCSIS 1.0+ and 1.1 Dynamic Profiles
When the Cisco uBR924 cable access router is running DOCSIS 1.0+ software, the router does not need
to request additional SIDs at registration time. Instead, the router specifies the number of phone lines
connected to the router, using the Vendor Specific Information Field (VSIF) in the DOCSIS
configuration file.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

1-15

Chapter 1

Overview

Supporting Multiple Classes of Service

When one of the phones connected to the Cisco uBR924 router is taken off-hook, the router sends an
Unsolicited Grant (UG) request to the CMTS, which responds by assigning a SID for that voice call. This
dynamically-created SID is assigned a secondary CoS profile that matches the type of call being made
(voice or fax). When the voice or fax call terminates, its SID is deleted so the bandwidth can be used by
another user.

Creating Multiple Profiles
In both DOCSIS 1.0 and 1.1 environments, the provider must create and maintain multiple CoS profiles
for voice and fax users. Typically, different CoS profiles are used for voice and fax traffic because these
services use different codec algorithms that have different timing requirements.
The provider could assign the same CoS profiles for all voice and fax users, or the provider could create
a number of different CoS profiles that provide different levels of service, depending on the number of
voice lines and other services purchased. This latter approach requires a method of associating a
particular profile with specific users.
For this purpose, Cisco offers a set of software products for DOCSIS provisioning of different CoS
profiles:
•

User Registrar for subscriber self-provisioning and administration

•

Modem Registrar for cable modem management

•

Cisco Network Registrar for DNS and DHCP services

•

Access Registrar for RADIUS services in one-way modems and roaming

This set of software products can be used by the service provider deploying a subscriber provisioning
system. The following sections describe each product in brief; for complete details, see the
Cisco Subscriber Registration Center documentation set, available in the Network Management section
of CCO and the customer documentation CD-ROM. Also see the Cisco Network Registrar for the
Cisco uBR7200 Series documentation.

User Registrar
User Registrar (UR) provides a set of web pages and extensions that enable subscriber self-registration.
User Registrar addresses the needs of three separate classes of users in the provisioning system
implemented by the customer (typically a service provider). This software tool addresses the needs of
the:
•

Subscriber who may be signing up for network services for the first time, or augmenting services.
The set of options for the subscriber is determined by the customer and will change between
customers, even in the same industry.

•

Administrator who will be called on to generate reports for individual users, generate system wide
reports and resolve provisioning system problems that a subscriber may have.

•

Configurer who is responsible for making modifications to the templates and workflows that define
a customer’s solution. This role may also involve building interfaces to the customer’s existing
business systems.

User Registrar includes the following features:
•

Web-based user interface, including HTML templates workflow scripts that provide a sample
out-of-the-box user provisioning system with a set of “extension points” for the most anticipated
customizations.

•

Multi-level subscriber service privileges

Cisco uBR924 Software Configuration Guide

1-16

OL-0337-05 (8/2002)

Chapter 1

Overview
Supporting Multiple Classes of Service

•

Subscriber authentication and service validation

•

Workflow scripts and templates can be customized as needed to suit a customer’s needs

•

Cable modem reset via SNMP

•

A preliminary set of NAS extensions to communicate with supported backend customer systems.
This includes interfaces to a central LDAP directory and Network Registrar (via NRCMD).

Modem Registrar
Modem Registrar (MR) provides dynamic generation of DOCSIS configuration files based on network
and service policies. It builds DOCSIS configuration files for clients based on parameters stored in an
LDAP directory. The customized DOCSIS configuration file is sent to the Cisco uBR924 cable access
router using TFTP as part of the normal modem registration process.
Modem Registrar includes the following features:
•

Policy based dynamic creation of DOCSIS configuration files

•

Web-based user interface to define the policies for creating configuration files

•

A fully functional TFTP server

Cisco Network Registrar
Cisco Network Registrar (CNR) supplies IP addresses and configuration parameters for DOCSIS cable
modems and PCs based on user-defined network and service policies. CNR also allocates host names for
these devices in DNS and the related information is stored in an LDAP directory.
CNR assigns available IP addresses from address pools based on the identity or type of the requesting
device and the policies in effect. For example, CNR can distinguish between registered devices,
unregistered devices, and registered devices that have been assigned to a particular class of service.
Key features of Cisco Network Registrar include:
•

DHCP server, with multiple address pools and multiple policies that can define different DHCP
options based on the address pool being used

•

DNS server and dynamic DNS updates

•

Verification of address usage prior to allocation

•

Address pools on multiple subnets, secondary subnets on the same wire, and BOOTP

•

DHCP operation over routers using BOOTP relay

•

CLI and web-based GUI access

Access Registrar
Access Registrar (AR) provides authorization and authentication services for DOCSIS-compliant
modems that operate in a one-way cable plant requiring telco-return for upstream data. AR services can
also provide dial-in data services for users who are roaming outside their cable service area. AR returns
configuration parameters from RADIUS servers to NAS clients based on per-subscriber policies, which
are obtained from an LDAP directory.

Note

AR does not apply to Cisco uBR924 cable access routers, which are two-way devices that do not require
telco-return services.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

1-17

Chapter 1

Overview

Supporting Multiple Classes of Service

Cisco uBR924 Software Configuration Guide

1-18

OL-0337-05 (8/2002)

C H A P T E R

DOCSIS-Bridging Configuration
This chapter describes the default configuration of the Cisco uBR924 cable access router. With this
configuration, the Cisco uBR924 router functions in its “plug and play” DOCSIS-bridging mode,
performing as a DOCSIS-compliant two-way cable modem. Every DOCSIS-compliant cable modem
provides the following minimum set of features:

Note

•

Automatically provisions and configures itself using the DOCSIS configuration file that is
downloaded from a server at the headend.

•

Acts as a transparent bridge to send IP data traffic between its Ethernet and cable interfaces,
providing connectivity from the customer’s system to the Internet backbone.

•

Provides Internet connectivity to PCs or other CPE devices connected to the Cisco uBR924 router.

In Cisco IOS Release 12.1, Voice over IP (VoIP) traffic is automatically supported when using the
DOCSIS-bridging mode. However, in Cisco IOS Release 12.0, the default “plug and play” image does
not enable the Cisco uBR924 router’s voice ports. To enable the voice ports, you must use a Cisco IOS
image with voice support and download an appropriate Cisco IOS configuration file. See Chapter 4,
“Voice over IP Configurations,” for more information.
The following sections describe the configuration for “plug and play” DOCSIS bridging:
•

DHCP Server Configuration, page 2-2

•

DOCSIS Configuration File, page 2-3

•

Cisco IOS Software Image, page 2-6

•

Cisco IOS Configuration File, page 2-7

•

Configuring the Attached CPE Devices, page 2-9

•

Reconfiguring DOCSIS-Compliant Bridging, page 2-9

The DHCP server configuration and DOCSIS configuration file are required for every
DOCSIS-compliant cable modem. The Cisco IOS image and configuration files are optional, depending
on the needs of the subscribers. The remaining configurations are optional, depending on the needs of
the subscribers.
The information described in this chapter applies to every Cisco uBR924 cable access router that is used
in a DOCSIS-compliant network. Additional configuration steps might be needed, however, to support
additional features, such as VoIP and IPSec encryption—this additional configuration is described in the
other chapters in this guide.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

2-1

Chapter 2

DOCSIS-Bridging Configuration

DHCP Server Configuration

Caution

Before attempting to reconfigure the Cisco uBR924 cable access router at a subscriber site, contact your
provisioning or billing system administrator to ensure remote configuration is allowed. If remote
configuration is disabled, settings you make and save at the local site will not remain in effect after the
Cisco uBR924 router is powered off and on. Instead, the router’s settings will return to the previous
configuration.

DHCP Server Configuration
The DOCSIS specification (SP-RFI-IO5-991105 or later revision) requires that a DOCSIS-compliant
cable modem connect to a DHCP server at power-on or reset to establish temporary IP connectivity with
the cable network. This enables the cable modem to download the additional configuration information
needed to establish a permanent connection with the headend and cable network.
The DHCP server can be a CMTS with DHCP server capabilities (such as a Cisco uBR7200 series
universal broadband router), or it can be a dedicated server located at the headend. The server can be
configured manually for each cable modem or it can be part of an automated provisioning system such
as Cisco Network Registrar (CNR).

Note

The DOCSIS specification requires that every DOCSIS cable modem obtain its IP address from an
authorized DHCP server during the reset or power-on provisioning process. Any IP address specified in
an IOS configuration file is overwritten by the one assigned by the DHCP server. The only way to assign
a static IP address to a cable modem is to configure the DHCP server so that it assigns the desired IP
address on the basis of the cable modem's MAC address. However, service providers should warn
subscribers that changes in the cable network's topology—due to traffic levels, growth, or changes to the
cable plant and other hardware—might still require changing the subnets and IP addresses assigned to a
particular cable modem.
The DHCP server provides the information shown in Table 2-1 to each cable modem.

Table 2-1

DHCP Server Parameters

Parameter

Description

IP address for the cable modem’s cable
interface

This IP address typically is assigned dynamically but the service provider can
also statically assign IP addresses on the basis of each modem’s MAC address.
Note

When the router is in DOCSIS-bridging mode, it automatically assigns
this IP address to both the cable and Ethernet interfaces. When the router
is in routing mode, it assigns this IP address only to the cable interface;
the IP address for the Ethernet interface must be configured separately.

IP subnet mask for the cable modem’s
cable interface

This subnet mask typically is used for all cable modems using the same
downstream, but this depends on the setup of the CMTS network as well as
subscribers’ needs.

IP address for the TFTP server

This TFTP server provides the DOCSIS configuration file to the cable modem
and is typically a dedicated server located at the headend.

Cisco uBR924 Software Configuration Guide

2-2

OL-0337-05 (8/2002)

Chapter 2

DOCSIS-Bridging Configuration
DOCSIS Configuration File

Table 2-1

DHCP Server Parameters (continued)

Parameter

Description

IP address for the DHCP relay agent

A DHCP relay agent is required if the DHCP server is located on a different
network than the IP address assigned to the cable modem’s cable interface. The
DHCP relay agent is also used if the DHCP server is providing IP addresses to
the CPE devices connected to the cable modem and the CPE devices are on a
different subnet than the cable modem.

Complete filename for the DOCSIS
configuration file

This is the filename for the DOCSIS configuration file that the cable modem
should download from the TFTP server.

IP address for one or more time of day
(ToD) servers

The cable modem uses the ToD server to get the current date and time so that it
can accurately timestamp its SNMP messages and error log entries.

One or more IP addresses for the routers Typically, the CMTS acts as the default gateway for the cable modem.
that will forward IP traffic from the cable
Note
Typically, the DHCP server sets the default gateway for DOCSIS cable
modem
modems. When this is done on Cisco routers, the default gateway does
not appear in the Cisco IOS configuration file, to indicate that the
gateway is being set dynamically by the DHCP server and should not be
saved after a reset of the router. To display the default gateway, use the
show ip default-gateway command.
One or more IP addresses for System Log The cable modem can send its error log messages to the SYSLOG servers, which
(SYSLOG) servers
are optional and typically located at the headend.
After making a successful DHCP request, the cable modem contacts the ToD server to get the current
date and time. It also begins the TFTP download of the DOCSIS configuration file, which is described
in the next section, “DOCSIS Configuration File” section on page 2-3.

Note

At this point in the registration process, the DHCP server provides an IP address only for the cable
modem, not for the CPE devices it is connecting to the network. The same DHCP server can provide the
IP addresses for the CPE devices after the cable modem goes online, or the cable modem itself can be
configured as a DHCP server (see “Routing with DHCP Server” section on page 3-4).

DOCSIS Configuration File
The DOCSIS specification requires that a DOCSIS-compliant cable modem download a DOCSIS
configuration file during its power-on or reset sequence. This file must be in the format described in the
SP-RFI-IO5-991105 specification (or later revision) and must contain the information shown in
Table 2-2.

Note

The parameters shown in Table 2-2 are organized according to the categories used in the Cisco DOCSIS
Cable Modem Configuration tool, which is available on CCO at
http://www.cisco.com/support/toolkit/CableModem. (You must have an account on CCO to access this
tool.)

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

2-3

Chapter 2

DOCSIS-Bridging Configuration

DOCSIS Configuration File

Table 2-2

DOCSIS Configuration File Parameters

Parameter1

Description

Radio Frequency Parameters
Downstream Frequency

Specifies the center frequency (in multiples of 62500 Hz) for the downstream channel to
be used by the router. (This parameter does not need to be specified in the configuration
file because the router will scan the downstream for available frequencies, but typically it
is specified to ensure that the router conforms to the provider’s channel plan.)

Upstream Channel ID

Specifies channel ID for the upstream channel to be used by the router. (This parameter
does not need to be specified in the configuration file because it can be set dynamically
by the CMTS during provisioning.)

Network Access Configuration

Determines whether CPE devices attached to the cable modem are allowed access to the
cable network. The default is to allow access for CPE devices (which is required for
normal operations).

Class of Service
Class of Service ID

Specifies the ID for this class of service (1–16).

Maximum Downstream Rate

Specifies the maximum downstream data rate (in bits/sec) allowed for traffic associated
with this class of service. (This is a limit, not a guarantee of service.)

Maximum Upstream Rate

Specifies the maximum upstream data rate (in bits/sec) allowed for traffic associated with
this class of service. (This is a limit, not a guarantee of service.)

Upstream Channel Priority

Specifies the priority for upstream traffic (0–7, where 7 is highest priority).

Minimum Upstream Rate

Specifies the minimum upstream data rate (in bits/sec) that is guaranteed for traffic
associated with this class of service.

Maximum Upstream Channel
Burst

Specifies the maximum size of burst traffic to be allowed on this upstream channel. The
size is specified in bytes, 0–65535, where 0 is no limit. If this field is set to a non-zero
value, it should be set to at least 1800 so that it is greater than the maximum Ethernet
frame size of 1518 plus the associated packet overhead).

Class of Service Privacy Enable

Specifies whether BPI encryption should be enabled on traffic associated with this class
of service (1 enables BPI encryption, 0 disables BPI encryption).

Vendor Specific Options
Vendor ID

The three-byte Organization Unique Identifier for the vendor, which is also usually the
first three bytes of the cable modem’s MAC address. This value is usually expressed as a
hexadecimal number. This field should be “00000C” for Cisco Systems routers.

Vendor-Specific Options

Contains any arbitrary values that are defined by the manufacturer of the cable modem.
The Cisco uBR924 cable access router uses this field to identify the Cisco IOS
configuration file that should be downloaded (if any). Arbitrary Cisco IOS commands can
also be specified in this field.

SNMP Management
SNMP Write-Access Control
and SNMP MIB Objects

Allows the service provider to set arbitrary SNMP attributes on the cable modem. For the
Cisco uBR924 router, these two fields are typically used to enable SNMP management of
the router because SNMP management is disabled by default.
Note

If using the Cisco DOCSIS Cable Modem Configurator tool, you can enable
SNMP management by filling in the IP address for the SNMP manager. The
Configurator tool then prepares the proper MIB objects to enable SNMP access.

Cisco uBR924 Software Configuration Guide

2-4

OL-0337-05 (8/2002)

Chapter 2

DOCSIS-Bridging Configuration
DOCSIS Configuration File

Table 2-2

DOCSIS Configuration File Parameters (continued)

Parameter1

Description

Baseline Privacy Interface Configuration
Authorize Wait Timeout

Specifies the retransmission interval, in seconds, of Authorization Request messages from
the Authorize Wait state. Valid values are 2–30 seconds.

Reauthorize Wait Timeout

Specifies the retransmission interval, in seconds, of Reauthorization Request messages
from the Authorize Wait state. Valid values are 2–30 seconds.

Authorization Grace Timeout

Specifies the grace period for re-authorization, in seconds. Valid values are 1–1800
seconds.

Operational Wait Timeout

Specifies the retransmission interval, in seconds, of Key Requests from the Operational
Wait state. Valid values are 1–10 seconds.

Rekey Wait Timeout

Specifies the retransmission interval, in seconds, of Key Requests from the Rekey Wait
state. Valid values are 1–10 seconds.

TEK Grace Time

Specifies the grace period for re-keying, in seconds. Valid values are 1–1800 seconds.

Authorize Reject Wait Timeout

Specifies how long, in seconds, a cable modem waits in the Authorize Reject Wait state
after receiving an Authorization Reject. Valid values are 60–1800 seconds.

Customer Premises Equipment
Maximum Number of CPEs

Determines the maximum number of CPE devices that can use the cable modem to
connect to the cable network. The default value is 1. In bridging mode, the
Cisco uBR924 router supports a maximum number of either 3 or 254 CPE devices,
depending on the Cisco IOS software release being used.

CPE Ethernet MAC Address

Configures the cable modem with the MAC addresses for one or more CPE devices that
are allowed to connect to the cable network. Entering values in this field is optional
because the cable modem can learn the MAC addresses of CPE devices dynamically, up
to the maximum allowable number. However, DOCSIS cable modems give priority to the
CPE devices whose MAC addresses are in the configuration file.

Software Upgrade
TFTP Software Server IP
Address

Specifies the IP address for the TFTP server that will provide software images. This server
does not necessarily have to be the same TFTP server that provided the DOCSIS
configuration file.

Software Image Filename

Specifies the fully qualified path name for the software image that the cable modem
should be running. If necessary, the cable modem uses TFTP to download this image from
the software server.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

2-5

Chapter 2

DOCSIS-Bridging Configuration

Cisco IOS Software Image

Table 2-2

DOCSIS Configuration File Parameters (continued)

Parameter1

Description

Miscellaneous
Concatenation Support

Specifies whether the cable modem supports DOCSIS 1.1 concatenation of upstream
packet requests.

Use RFC2104 HMAC-MD5

Specifies the algorithm used to compute the CMTS Message Integrity Check (MIC). If
yes, the HMAC-MD5 algorithm specified in RFC 2104 is used; otherwise, the algorithm
specified by RFC 1321 is used. (The algorithm used must match the one used on the
CMTS.)
Note

CMTS Authentication

Because the RFC 1321 algorithm can be reversed, Cisco strongly recommends the
use of only the more secure HMAC-MD5 algorithm.

Specifies an authentication string to be used between the provisioning server (which
creates the configuration files) and the CMTS. It allows the CMTS to authenticate the CM
provisioning with a central authentication service, such as a RADIUS server. This field is
typically used only for one-way cable modems that use telco-return.

1. The DOCSIS configuration file also contains fields for one-way cable modems that use telco-return, but these fields do not apply to the
Cisco uBR924 router, which is a two-way cable modem.

Cisco IOS Software Image
The DOCSIS configuration file contains the filename for the software image that the
Cisco uBR924 router must be running. If this filename does not match the software image that is
currently installed on the router, the router must use the TFTP protocol to download the new image from
the server specified in the DOCSIS configuration file.
After the new software image has been downloaded, the Cisco uBR924 router resets itself and repeats
the entire power-on and provisioning process. This includes downloading the DOCSIS configuration file
again. However, because the software image is stored in non-volatile Flash memory, the router does not
have to download it again—the software download occurs only when the service provider specifies a new
software image filename in the DOCSIS configuration file.
If the Cisco uBR924 router cannot download the new image, it retries the download, up to a maximum
of 16 attempts. If the router still cannot download the image, it falls back to its previous software image
and attempts to go online with that image.
The service provider can also force the Cisco uBR924 router to download new software by putting a new
image filename in the DOCSIS configuration file and resetting the router. This should be done only after
warning the customer that the modem will be offline for a period of several minutes.

Note

Because it can take several minutes for this download to be accomplished and for the
Cisco uBR924 router to repeat its power-on sequence, the desired software image can also be installed
on the router at the warehouse. In this case, the DOCSIS configuration files for each router should also
be updated with the proper filename.

Cisco uBR924 Software Configuration Guide

2-6

OL-0337-05 (8/2002)

Chapter 2

DOCSIS-Bridging Configuration
Cisco IOS Configuration File

Cisco IOS Configuration File
The DOCSIS configuration file uses the type 43 Vendor-Specific Options field to specify that the
Cisco uBR924 router should download a Cisco IOS configuration file. The router’s console port is
automatically disabled as part of this process to prevent users at the remote site from reconfiguring the
router.

Note

Downloading a Cisco IOS configuration file is not usually required for plug-and-play bridging. Instead,
it is normally used to configure the advanced feature sets that are described in the other chapters of this
guide.

Using the Vendor-Specific Information Field
Table 2-3 shows the values that would be entered in the Vendor-Specific Information Field (VSIF) to
download a Cisco IOS configuration file and automatically disable the console port.
Table 2-3

Downloading a Cisco IOS Configuration File (with console port disabled)

Field

Value

Subtype

128

Length

(number of characters in the filename)

Filename

Complete filename, including path, for the Cisco IOS configuration file on the
TFTP servers specified in the DOCSIS configuration file.
Note

The Cisco IOS configuration file can contain only global configuration
mode commands, not Privileged EXEC commands.

Table 2-4 shows the values that would be entered in the Vendor-Specific Information Field (VSIF) to
specify a CLI command that should be executed after the Cisco uBR924 cable access router processes
the DOCSIS configuration file and comes online.
Table 2-4

Specifying CLI Commands

Field

Value

Subtype

131

Length

(number of characters in the command)

CLI Command

The ASCII characters of one CLI command, as you would type it at the CLI
prompt. To specify multiple commands, use this option once for each command.
Note

Tip

You can specify only global configuration mode commands, not Privileged
EXEC commands, in this field.

The VSIF option to include CLI commands in the DOCSIS configuration file should be used to
specify a very limited number of commands for specialized applications. To perform a more
substantial configuration of the router, use VSIF option 128 to download a Cisco IOS configuration
file. Also see Appendix A, “Using Cisco IOS Software.”

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

2-7

Chapter 2

DOCSIS-Bridging Configuration

Cisco IOS Configuration File

Sample Configuration for DOCSIS-Compliant Bridging
The following shows a typical Cisco IOS configuration for a Cisco uBR924 router that is operating in
“plug and play” DOCSIS-compliant bridging mode.
version 12.1
service config
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname ubr924
!
clock timezone - 4
ip subnet-zero
no ip routing
!
voice-port 0
!
voice-port 1
!
interface Ethernet0
no ip directed-broadcast
no ip route-cache
bridge-group 59
bridge-group 59 spanning-disabled
!
interface cable-modem0
ip address dhcp
no ip directed-broadcast
no ip route-cache
bridge-group 59
bridge-group 59 spanning-disabled
!
ip classless
no ip http server
no service finger
!
!
line con 0
transport input none
line vty 0 4
!
end

This configuration shows the following requirements for DOCSIS-compliant bridging:
•

IP routing is disabled.

•

No IP address is assigned to the cable interface; instead, the ip address dhcp command indicates
that a DHCP server assigns an IP address to the cable interface. The Ethernet interface uses the same
IP address because the router is acting as a bridge between the two interfaces, making them part of
the same IP network—when the router is in DOCSIS-bridging mode, the IP addresses are
automatically assigned during the provisioning process.

Cisco uBR924 Software Configuration Guide

2-8

OL-0337-05 (8/2002)

Chapter 2

DOCSIS-Bridging Configuration
Configuring the Attached CPE Devices

Configuring the Attached CPE Devices
In its “plug-and-play” bridging mode, the Cisco uBR924 router does not need any additional
configuration to support the computers or other CPE devices that will access the Internet through the
router’s connection to the cable network. However, the PCs and CPE devices must be configured to
support DHCP allocation of IP addresses.
Each computer and CPE device performs this configuration differently. For Windows 95, for example,
you would open up the Network control panel, select the computer’s TCP/IP Ethernet adapter, and set
the IP address configuration to “Obtain and IP address automatically.”

Reconfiguring DOCSIS-Compliant Bridging
To reconfigure the Cisco uBR924 router to support DOCSIS-compliant bridging after it has been
configured for routing, log in to the Cisco uBR924 router, enter global configuration mode, and enter the
following commands:
Command

Purpose

Step 1

uBR924(config)#no ip routing

Disable IP routing on the Cisco uBR924 router.

Step 2

uBR924(config)#int e 0

Enter interface configuration mode for the Ethernet
interface.

Step 3

uBR924(config-if)# no ip address

Remove the IP address from the Ethernet interface.

Step 4

uBR924(config-if)# no ip route-cache

Remove the high-speed switching caches for IP
routing.

Step 5

uBR924(config-if)# bridge-group bridge-group

Assign the Ethernet interface to a bridge spanning
group (choose an arbitrary integer from 1–63).

Step 6

uBR924(config-if)# bridge-group bridge-group
spanning-disabled

Disable the spanning tree on the Ethernet interface.

Step 7

uBR924(config-if)# exit

Exit the interface configuration mode for the
Ethernet interface.

Step 8

uBR924(config)# int c 0

Enter interface configuration mode for the cable
interface.

Step 9

uBR924(config-if)# no ip address

Remove the IP address from the cable interface.

Step 10

uBR924(config-if)# no keep alive

Disable keepalive messages on the cable interface.

Step 11

uBR924(config-if)# no ip route-cache

Remove the high-speed switching caches for IP
routing.

Step 12

uBR924(config-if)# cable modem compliant bridge

Enable DOCSIS-compliant bridging.

Step 13

uBR924(config-if)# bridge-group bridge-group

Assign the cable interface to the same bridge
spanning group used for the Ethernet interface.

Step 14

uBR924(config-if)# bridge-group bridge-group
spanning-disabled

Disable the spanning tree on the cable interface.

Step 15

uBR924(config-if)# Ctrl-Z

Return to privileged EXEC mode.

Step 16

uBR924# copy running-config startup-config

Save the configuration to nonvolatile RAM.

Step 17

uBR924# show startup-config

Display the configuration file that was just created.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

2-9

Chapter 2

DOCSIS-Bridging Configuration

Reconfiguring DOCSIS-Compliant Bridging

Cisco uBR924 Software Configuration Guide

2-10

OL-0337-05 (8/2002)

C H A P T E R

Advanced Data-Only Configurations
This chapter describes how to configure the Cisco uBR924 cable access router for data operation with
features beyond those supported in the default operation mode of “plug and play” DOCSIS bridging. The
following configurations are described:
•

Data-Only Routing, page 3-2

•

Routing with DHCP Server, page 3-4

•

NAT/PAT Configuration, page 3-6

•

NAT/PAT Configuration with DHCP Proxy, page 3-8

•

IPSec (56-bit) Example, page 3-11

•

IPSec (3DES) Example, page 3-16

•

L2TP Example, page 3-17

Depending on the Cisco IOS software image being used and the feature sets it supports, these
configurations could be combined.

Tip

Caution

Use the commands shown in this chapter to set up a typical Cisco uBR924 router for the desired feature.
Then save the configuration into a configuration file that can be downloaded to the router during
power-on or reset.

Incorrectly configuring the Cisco uBR924 cable access router can cause loss of network connectivity.
Before attempting to reconfigure the router, print the last working configuration, and ensure remote
configuration is enabled for the site.
If the router does not connect to the network after you have reconfigured it, enter the cable downstream
saved frequency from the printout, and then clear the interface. Power off and then power on the router.
If powering off the router does not correct the problem after a few minutes, give the write erase and
copy startup-config running-config commands; then enter the correct saved downstream frequency. If
network connectivity is not restored, contact your network management, provisioning, or billing system
administrator to reload the software applicable to your network.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

3-1

Chapter 3

Advanced Data-Only Configurations

Data-Only Routing

Data-Only Routing
The Cisco uBR924 router must be configured for routing mode to use advanced features such as IPSec
encryption and firewall protection. The routing mode is also required if the PCs attached to the
Cisco uBR924 router are on a private network or on a different subnet than the subnet used by the CMTS.
The following steps are required to configure the routing mode on the Cisco uBR924 router:
•

Disable DOCSIS-compliant bridging on the cable interface with the no cable modem compliant
bridge interface command.

•

Remove the bridge group on the cable and Ethernet interfaces with the no bridge group interface
command.

•

Configure the RIPv2 routing protocol (or static routes) on the cable and Ethernet interfaces.

To configure the Cisco uBR924 router, log in to the router, enter global configuration mode, and enter
the following commands:
Command

Purpose

Step 1

uBR924(config)#int c 0

Enter interface configuration mode for the cable
interface.

Step 2

uBR924(config-if)# no cable-modem compliant bridge

Disable DOCSIS-compliant bridging.

Step 3

uBR924(config-if)# no bridge group number

Remove the bridge group.

Step 4

uBR924(config-if)# ip address dhcp

Configure the cable interface to receive an IP
address from the DHCP server.

Step 5

uBR924(config-if)# exit

Return to global configuration mode.

Step 6

uBR924(config)#int e 0

Enter interface configuration mode for Ethernet 0.

Step 7

uBR924(config-if)# no bridge group number

Remove the bridge group.

Step 8

uBR924(config-if)# ip address ip-address subnet-mask

Enter the Ethernet interface’s IP address and subnet
mask.

Step 9

uBR924(config-if)# exit

Return to global configuration mode.

Step 10

uBR924(config)# ip routing
To use RIPv2:
uBR924(config)#router rip

Enable IP routing for the router.

uBR924(config-router)# version 2

Enable RIP version 2 routing.

uBR924(config-router)# network cable-network-number

Enable routing on the cable interface’s IP network.

Step 11

Enter router configuration mode.

uBR924(config-router)# network Ethernet-network-number Enable routing on the Ethernet interface’s IP
network.
uBR924(config-router)# exit

Return to global configuration mode.

Step 12

uBR924(config)# no cdp run

(Optional) Disable the Cisco Discovery Protocol
(CDP) on the router. CDP is a proprietary protocol
for the discovery of Cisco routers running protocols
other than TCP/IP; because DOCSIS cable data
networks are primarily TCP/IP networks, CDP is not
necessary on the Cisco uBR924 router.

Step 13

uBR924(config)# ip default-gateway ip-address

Set the default gateway for routing (typically, this is
the CMTS).

Cisco uBR924 Software Configuration Guide

3-2

OL-0337-05 (8/2002)

Chapter 3

Advanced Data-Only Configurations
Data-Only Routing

Command

Purpose

Step 14

uBR924(config)# ip classless

(Optional) Enable the forwarding of packets that are
destined for unrecognized subnets to the best
supernet route.

Step 15

uBR924(config)# ip route 0.0.0.0 0.0.0.0 ip-address

(Optional) Establish a static route so that all packets
without an established route are forwarded to the
default gateway (typically the ip-address should be
the IP address for the CMTS), regardless of any
routing metrics.

Step 16

uBR924(config-if)# Ctrl-z

Return to privileged EXEC mode.

Step 17

uBR924# copy running-config startup-config
Building configuration...

Save the configuration to nonvolatile memory so
that it will not be lost in the event of a reset, power
cycle, or power outage.

Step 18

uBR924# show startup-config

Display the configuration file that was just created.

Step 19

uBR924# reload

Resets the router and cable interface to enable IP
routing mode.

To verify that routing is enabled, enter the show startup-config command. The following example
shows a sample configuration file for basic data-only routing mode; the relevant commands are shown
in bold.
version 12.1
service config
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname Router
!
clock timezone - 4
ip subnet-zero
!
voice-port 0
!
voice-port 1
!
interface Ethernet0
ip address 172.16.0.1 255.255.0.0
no ip directed-broadcast
ip rip send version 2
ip rip receive version 2
!
interface cable-modem0
ip address dhcp
no ip directed-broadcast
ip rip send version 2
ip rip receive version 2
no cable-modem compliant bridge
!
router rip
version 2
network 10.0.0.0
network 172.16.0.0
!
ip classless
no ip http server

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

3-3

Chapter 3

Advanced Data-Only Configurations

Routing with DHCP Server

no service finger
!
!
line con 0
transport input none
line vty 0 4
!
end

Note

The above configuration assumes that the DHCP server assigns an IP address to the cable interface that
is in the class A private network (10.0.0.0).

Routing with DHCP Server
When in routing mode, the Cisco uBR924 router can act as a DHCP server for the CPE devices it is
connecting to the cable network. A service provider then does not have to be concerned about providing
IP addresses to all of the PCs at a subscriber’s site; instead, the provider supplies a pool of IP addresses
that the Cisco uBR924 router then allocates to the PCs as needed.

Note

The Cisco uBR924 router must be configured for routing mode to act as a DHCP server. If in bridging
mode, you can configure the router to proxy DHCP client requests to the DHCP server at the headend
by giving the cable helper-address dhcp-server-ip-address host interface configuration command. (The
ip helper-address and ip forward-protocol interface configuration commands can also be used for this
purpose.)
To configure the Cisco uBR924 router to act as a DHCP server, log in to the router, enter global
configuration mode, and enter the following commands:

Command

Purpose

Step 1

uBR924(config)# ip dhcp pool pool-name

Create an address pool for the DHCP server named
pool-name and enter DHCP configuration mode.

Step 2

uBR924(config-dhcp)# network IP-network-number
subnet-mask

Specify the network number and subnet mask for the IP
address pool. These IP addresses should be part of the
subnet provided by the CMTS cable interface. For
example, network 10.17.91.0 255.255.255.0 reserves the
IP addresses 10.17.91.1–10.17.91.254 for CPE devices.

Step 3

uBR924(config-dhcp)# domain-name domain-name

The domain name that should be assigned to CPE devices
(for example, cisco.com).

Step 4

uBR924(config-dhcp)# dns-server ip-address

The IP address for the DNS server provided by the service
provider that will service the DNS requests from the CPE
devices. More than one DNS server can be specified.

Step 5

uBR924(config-dhcp)# default-router ip-address

The IP address for the default router for the CPE devices
(typically, this is the CMTS). More than one default router
can be specified.

Step 6

uBR924(config-dhcp)# exit

Return to global configuration mode.

Step 7

uBR924# show startup-config

Display the configuration file that was just created.

Cisco uBR924 Software Configuration Guide

3-4

OL-0337-05 (8/2002)

Chapter 3

Advanced Data-Only Configurations
Routing with DHCP Server

To verify that the DHCP server is enabled, enter the show startup-config command. A sample
configuration file for a Cisco uBR924 router acting as a DHCP server is shown below. The relevant
commands are shown in bold.
version 12.1
service config
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname Router
!
clock timezone - 4
ip subnet-zero
!
ip dhcp pool Clients
network 192.168.100.0 255.255.255.0
domain-name cisco.com
dns-server 192.168.100.17
default-router 192.168.101.1
!
voice-port 0
!
voice-port 1
!
interface Ethernet0
ip address 192.168.100.1 255.255.0.0
no ip directed-broadcast
ip rip send version 2
ip rip receive version 2
!
interface cable-modem0
ip address dhcp
no ip directed-broadcast
ip rip send version 2
ip rip receive version 2
no cable-modem compliant bridge
!
router rip
version 2
network 10.0.0.0
network 192.168.100.0
!
ip classless
no ip http server
no service finger
!
!
line con 0
transport input none
line vty 0 4
!
end

Note

The above configuration assumes that the DHCP server assigns an IP address to the cable interface that
is in the class A private network (10.0.0.0).

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

3-5

Chapter 3

Advanced Data-Only Configurations

NAT/PAT Configuration

NAT/PAT Configuration
When using a Cisco IOS image that supports the Easy IP feature, the Cisco uBR924 router supports
Network Address Translation (NAT) and Port Address Translation (PAT). This allows a private network
that is connected to the router to use the same IP address when communicating through the cable
interface to the Internet or other public networks.
When NAT/PAT are enabled on the cable access router, the “inside” network is the private network
connected to the router’s Ethernet interface, and the “outside” network is the network accessed through
the cable network (such as the Internet or a company’s larger network). Each inside address is typically
an IP address in the RFC1918 private network space (10.0.0.0, 172.16.0.0, and 192.168.100.0) and is
translated to an external IP address that is valid in the outside network.

Note

NAT/PAT can be used only in routing mode.
The following commands show a typical configuration. (These steps assume that the router has already
been configured for routing mode, as described in “Data-Only Routing” section on page 3-2.)

Command

Purpose

Step 1

uBR924(config)# ip nat inside source list list-id interface
cable-modem0 overload

Enable translation of the inside source
addresses—the “inside” addresses are translated
before being presented to the “outside” network.
The list-id specifies an access-list that defines the IP
addresses that will be used, and overload specifies
that multiple inside IP addresses can use the same
outside IP address (but using different port numbers
to unique identify each inside host).

Step 2

uBR924(config)# interface Ethernet0

Enter interface configuration mode for the router’s
Ethernet interface.

Step 3

uBR924(config-if)# ip nat inside

Specify that the Ethernet is the “inside” of the
NAT/PAT translation.

Step 4

uBR924(config-if)# exit

Exit interface configuration mode.

Step 5

uBR924(config)# interface cable-modem0

Enter interface configuration mode for the router’s
cable interface.

Step 6

uBR924(config-if)# ip nat outside

Specify that the cable interface is the “outside” of
the NAT/PAT translation.

Step 7

uBR924(config-if)# exit

Exit interface configuration mode.

Step 8

uBR924(config)# access-list list-id permit address mask

Creates the access list specified by the list-id
parameter in the ip nat inside source command. The
address and mask values should specify IP addresses
that belong to the private IP network space being
used by the Ethernet interface.

Step 9

uBR924# copy running-config startup-config
Building configuration...

Save the configuration to nonvolatile memory so
that it will not be lost in the event of a reset, power
cycle, or power outage.

Step 10

uBR924# show startup-config

Display the configuration file that was just created.

Cisco uBR924 Software Configuration Guide

3-6

OL-0337-05 (8/2002)

Chapter 3

Advanced Data-Only Configurations
NAT/PAT Configuration

Note

Additional options, such as static IP address translation, are possible when using NAT/PAT. For more
information about the Easy IP and NAT/PAT feature set, see the Dial-Related Addressing Services
documentation, available on CCO and the Documentation CD-ROM.
The following configuration shows an example of a Cisco uBR924 router in routing mode that performs
NAT/PAT translation on all IP addresses connected to the router’s Ethernet interface. The external IP
address is overloaded so that multiple IP addresses on the internal network can use the same external IP
address over the cable interface; different port numbers are used to uniquely identify each device on the
Ethernet interface. The relevant commands are shown in bold.
version 12.1
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname uBR924
!
!
ip nat inside source list 1 interface cable-modem0 overload
clock timezone - -4
!
!
interface Ethernet0
ip address 192.168.1.1. 255.255.255.0
ip nat inside
!
interface cable-modem0
ip nat outside
no cable-modem compliant bridge
!
ip routing
ip default-gateway 10.1.1.1
ip classless
no ip http server
no service finger
ip route 0.0.0.0 0.0.0.0 10.1.1.1
!
access-list 1 permit 192.168.1.0 0.0.0.255
!
!
line con 0
line vty 0 4
login
!
end

Note

The above configuration assumes that the DHCP server assigns an IP address to the cable interface that
is in the class C private network (192.168.100.0).

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

3-7

Chapter 3

Advanced Data-Only Configurations

NAT/PAT Configuration with DHCP Proxy

NAT/PAT Configuration with DHCP Proxy
The NAT/PAT feature can also be used with the cable-modem dhcp-proxy nat command, so that the
router obtains the IP address used for the NAT pool for the Ethernet interface from the DHCP server.
This allows the service provider to dynamically provide this IP address in the same manner as for the
cable interface.
In addition to using the the cable-modem dhcp-proxy nat command, you must also use the following
NAT configuration commands:
•

Use the ip nat inside interface command to configure the Ethernet interface as the “inside”
interface.

•

Use the ip nat outside interface command to configure the cable interface as the “outside” interface.

•

Specify the overload option with the ip nat global configuration command because the NAT pool
created by the cable-modem dhcp-proxy command contains only one IP address.

The following commands show a typical configuration. (These steps assume that the router has already
been configured for routing mode, as described in “Data-Only Routing” section on page 3-2.)
Command

Purpose

Step 1

UBR924(config)# ip nat inside source list list-id interface Enables translation of the inside source
cable-modem0 overload
addresses—the “inside” addresses are translated
before being presented to the “outside” network.
The list-id specifies an access-list that defines the IP
addresses that will be used, and overload specifies
that multiple inside IP addresses can use the same
outside IP address (but using different port numbers
to unique identify each inside host).

Step 2

UBR924(config)# interface Ethernet0

Enters interface configuration mode for the router’s
Ethernet interface.

Step 3

UBR924(config-if)# ip nat inside

Specifies that the Ethernet is the “inside” of the
NAT/PAT translation.

Step 4

UBR924(config-if)# exit

Exits interface configuration mode.

Step 5

UBR924(config)# interface cable-modem0

Enters interface configuration mode for the router’s
cable interface.

Step 6

UBR924(config-if)# cable-modem dhcp-proxy nat
pool-name

Specifies the name of the NAT pool to be created
using the IP address and subnet mask supplied by the
DHCP server. The pool-name can be any arbitrary
string.
Note

This is equivalent to giving the ip nat pool
command, using the IP address and subnet
mask supplied by the DHCP server.

Step 7

UBR924(config-if)# ip nat outside

Specifies that the cable interface is the “outside” of
the NAT/PAT translation.

Step 8

UBR924(config-if)# exit

Exits interface configuration mode.

Cisco uBR924 Software Configuration Guide

3-8

OL-0337-05 (8/2002)

Chapter 3

Advanced Data-Only Configurations
NAT/PAT Configuration with DHCP Proxy

Command

Purpose

Step 9

UBR924(config)# access-list list-id permit address mask

Step 10

UBR924# copy running-config startup-config

Saves the configuration to nonvolatile memory so
that it will not be lost in the event of a reset, power
cycle, or power outage.

Step 11

UBR924# show startup-config

Displays the configuration file that was just created.

Note

For more information about the Easy IP and NAT/PAT feature set, see the Dial-Related Addressing
Services documentation, available on Cisco.com and the Documentation CD-ROM.
The following configuration for the Cisco uBR924 cable access router shows an example of a cable
access router in routing mode that performs NAT/PAT translation using the DHCP proxy to obtain its
NAT address pool. The relevant commands are shown in bold.

Note

Do not enter the ip nat pool command manually. The router automatically generates this command when
it obtains the NAT address pool from the DHCP server.
version 12.1
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname Router
!
!
ip nat inside source list 1 interface cable-modem0 overload
clock timezone - -4
!
!
interface Ethernet0
ip address 192.168.1.1 255.255.255.0
ip nat inside
!
interface cable-modem0
ip nat outside
no cable-modem compliant bridge
cable-modem dhcp-proxy nat nat-pool
!
ip routing
ip default-gateway 10.1.1.1
! The following command is automatically added when the router obtains
! the DHCP-provided IP addresses for the NAT pool
ip nat pool nat-pool 10.15.0.10 10.15.0.10 netmask 255.255.0.0
! The following command must be manually entered
ip nat inside source list 1 pool nat-pool overload
ip classless
no ip http server
no service finger
ip route 0.0.0.0 0.0.0.0 10.1.1.1

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

3-9

Chapter 3

Advanced Data-Only Configurations

NAT/PAT Configuration with DHCP Proxy

access-list 1 permit 192.168.1.0 0.0.0.255
!
!
line con 0
line vty 0 4
login
!
end

Note

The above configuration assumes that the DHCP server assigns an IP address to the cable interface that
is in the class C private network (192.168.0.0).

Using NAT and DHCP Proxy and Copying Configuration Files
Most service providers typically create a standard configuration file for their cable modems, verify it,
and then copy the working configuration as needed to other cable modems. This can cause problems with
Cisco uBR924 cable access router when using the cable-modem dhcp-proxy command to create a NAT
address pool for NAT/PAT translation.
The reason is that the default router configuration is for DOCSIS-compliant bridging, which includes
two bridge-group 59 commands for each interface. To use the cable-modem dhcp-proxy command,
you must put the router into routing mode, which means removing the bridge-group commands with the
equivalent no bridge-group commands.
However, because no bridge-group is the default for these CLI commands, they are not saved in the
running configuration. So when you save the Cisco IOS configuration file and copy it to other
Cisco uBR924 cable access router, the router is only partially configured for routing mode and
continually resets its interfaces.
In addition, whenever you use the cable-modem dhcp-proxy command to create a NAT pool, the router
automatically adds the appropriate ip nat pool commands to the configuration when it receives the actual
IP addresses from the DHCP server. The IP addresses specified in this command are particular to each
user and should not be copied to other routers.
To avoid this problem, use the following procedure to create a Cisco IOS configuration file that uses the
cable-modem dhcp-proxy command to create a NAT address pool for NAT/PAT address translation:
Step 1

Create and test a working configuration on a Cisco uBR924 cable access router.

Step 2

After you have created a standardized configuration, save it to memory, and then copy the Cisco IOS
configuration file to the TFTP server that will be used to copy the file to the other cable access routers.

Step 3

Open the Cisco IOS configuration file with a text editor and add the following lines underneath each
interface:
no bridge-group 59
no bridge-group 59 spanning-disabled

Step 4

Remove the ip nat pool command.

For example, the following are the relevant lines in a typical DHCP proxy NAT configuration for the
Cisco uBR924 cable access router:
interface Ethernet0
ip address 192.168.1.1 255.255.255.0
ip nat inside

Cisco uBR924 Software Configuration Guide

3-10

OL-0337-05 (8/2002)

Chapter 3

Advanced Data-Only Configurations
IPSec (56-bit) Example

load-interval 30
!
interface cable-modem0
ip nat outside
load-interval 30
no cable-modem compliant bridge
cable-modem dhcp-proxy nat nat-pool
!
ip nat pool nat-pool 10.15.0.10 10.15.0.10 netmask 255.255.0.0

When you copy this configuration file to the TFTP server, modify this portion of the configuration file
to add the no bridge-group commands under each interface and to remove the ip nat pool command:
interface Ethernet0
ip address 192.168.1.1 255.255.255.0
ip nat inside
load-interval 30
no bridge-group 59
no bridge-group 59 spanning-disabled
!
interface cable-modem0
ip nat outside
load-interval 30
no cable-modem compliant bridge
cable-modem dhcp-proxy nat nat-pool
no bridge-group 59
no bridge-group 59 spanning-disabled
!

Note

Be sure to remove the ip nat pool command.

IPSec (56-bit) Example
IPSec encryption provides end-to-end encryption of IP traffic across unprotected public networks such
as the Internet. To use IPSec, the Cisco uBR924 cable access router must meet the following
prerequisites:
•

The Cisco uBR924 router must be using a Cisco IOS Release 12.0(5)T or higher image that supports
the IPSec feature set.

•

The Cisco uBR924 router must be configured for routing mode.

•

The Cisco uBR924 router and endpoint must both support IPSec encryption and be configured for
the same encryption policy. (The endpoint is typically an IPSec gateway such as a peer router,
PIX firewall, or other device that can be configured for IPSec.)

Note

Images that support encryption are subject to United States government export controls and have limited
distribution. Strong encryption images to be installed outside the United States may require an export
license. Contact your sales representative or distributor for more information, or send an e-mail to
export@cisco.com.

Note

Cisco IOS Release 12.1(5)T, 12.2(2), or greater is required to support GRE IP tunnels.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

3-11

Chapter 3

Advanced Data-Only Configurations

IPSec (56-bit) Example

The configuration of the Cisco uBR924 router for IPSec encryption depends on the application involved,
such as whether the IPSec encryption is part of a virtual private network (VPN) and whether the
Cisco uBR924 router should encrypt traffic to one or more than one peer end-point. A technique that
would work well for a small network might not scale well for a large network—for example, using
pre-shared authentication keys works for networks of up to 10 or so nodes, but larger networks should
use RSA public key signatures and digital certificates.

Note

For more information about IPSec, as well as related topics such as Internet Key Exchange (IKE),
Internet Security Association Key Management Protocol/Oakley variation (ISAKMP/Oakley), and
digital certificates, see the “Additional Documentation” section on page 3-15.
The following shows the commands needed to configure the Cisco uBR924 router for IPSec encryption
with one peer router, using pre-shared keys.

Command

Purpose

Step 1

uBR924(config)# crypto isakmp enable

Enable the use of ISAKMP/IKE on the
Cisco uBR924 router.

Step 2

uBR924(config)# crypto isakmp policy priority-number

Creates an IKE policy with the specified
priority-number (1–10000, where 1 is the highest
priority) and enters ISAKMP policy configuration
command mode.

Step 3

uBR924(config-isakmp)# encryption des

Specifies that 56-bit DES encryption be used. to
encrypt the data.

Step 4

uBR924(config-isakmp)# hash md5

Specifies the MD5 (HMAC variant) hash algorithm
for packet authentication.

Step 5

ubr924(config-isakmp)# group 1

Specifies the 768-bit Diffie-Hellman group for key
negotiation.

Step 6

uBR924(config-isakmp)# authentication pre-share

Specifies that the authentication keys are pre-shared,
as opposed to dynamically negotiated using RSA
public key signatures.

Step 7

uBR924(config-isakmp)# lifetime seconds

Defines how long each security association should
exist before expiring (60 seconds to 86,400
seconds).

Step 8

uBR924(config-isakmp)# exit

Exits ISAKMP policy configuration command
mode.

Step 9

uBR924(config)# crypto isakmp key shared-key address
ip-address

Specifies the pre-shared key that should be used
with the peer at the specific IP address. The key can
be any arbitrary alphanumeric key up to 128
characters long—the key is case-sensitive and must
be entered identically on both routers.
Note

You can also specify a pre-shared key using
the crypto key public-chain dss command.
See the description of this command in the
Cisco Encryption Technology Commands
document, available on CCO and the
Documentation CD-ROM.

Cisco uBR924 Software Configuration Guide

3-12

OL-0337-05 (8/2002)

Chapter 3

Advanced Data-Only Configurations
IPSec (56-bit) Example

Command

Purpose

Step 10

uBR924(config)# crypto isakmp identity hostname

Sets the ISAKMP identity of the router to its host
name concatenated with the domain name (for
example, ubr924.cisco.com).

Step 11

uBR924(config)# crypto ipsec transform-set
transform-set-name transform1 transform2 transform3

Establishes the transform set to be used for IPSec
encryption. Up to three transformations can be
specified for a set, such as ah-md5-hmac esp-des
esp-md5-hmac.

Step 12

uBR924(config)# crypto map crypto-map-name
local-address cable-modem0

Creates the specified crypto map and applies it to the
cable interface.

Step 13

uBR924(config)# crypto map crypto-map-name 10
ipsec-isakmp

Creates a crypto map numbered 10 and enters the
crypto map configuration mode.

Step 14

uBR924(config-crypto)# set peer ip-address

Identifies the IP address for the destination peer
router.

Step 15

uBR924(config-crypto)# set transform-set
transform-set-name

Sets the crypto map to use the transform set created
previously.

Step 16

uBR924(config-crypto)# match address access-list-number Sets the crypto map to use the access list that will
specify the type of traffic to be encrypted.
Note

Access lists 100 and 101 cannot be used
because they are reserved for DOCSIS use.

Step 17

uBR924(config-crypto)# exit

Exits crypto map configuration mode.

Step 18

uBR924(config)# int c 0

Enters interface configuration mode for the cable
interface.

Step 19

uBR924 (config-if)# crypto map crypto-map-name

Applies the crypto map created above to the cable
interface.

Step 20

uBR924 (config-if)# access-list access-list-number permit
ip host ubr924-ip-address peer-ip-address filter-mask

Creates an access list to identify the traffic that will
be encrypted. (This should match the access list
created above.)

Step 21

uBR924(config-if)# Ctrl-z

Return to privileged EXEC mode.

Step 22

uBR924# copy running-config startup-config
Building configuration...

Save the configuration to nonvolatile memory so
that it will not be lost in the event of a reset, power
cycle, or power outage.

Step 23

uBR924# show startup-config

Display the configuration file that was just created.

Note

To enable IPSec encryption, the peer router must also be configured for IPSec encryption, using the
identical parameters used on the Cisco uBR924 router.

Sample Configuration
The following configuration shows a typical IPSec configuration with the following parameters:
•

The IKE policy is defined as policy priority 1 with the following parameters:

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

3-13

Chapter 3

Advanced Data-Only Configurations

IPSec (56-bit) Example

– 56-bit DES-CBC encryption (the default)
– MD5 (HMAC variant) hash algorithm
– Pre-shared authentication keys
– 768-bit Diffie-Hellman group (the default)
– Security association lifetime of 5,000 seconds (approximately 83 minutes).
•

The pre-shared key has the value 1234567890 (normally keys would be much more complex than
this simple example)

•

IPSec encryption is being done on traffic sent from the cable interface on the Cisco uBR924 router
(at IP address 10.1.0.25).

•

One single peer is defined—the router at IP address 30.1.1.1.

•

IPSec encryption is applied to all traffic that matches the contents of access list 200.

IPSec-related commands are shown in bold.
version 12.1
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname Router
!
clock timezone - 0 6
ip subnet-zero
no ip domain-lookup
!
crypto isakmp policy 1
hash md5
authentication pre-share
lifetime 5000
crypto isakmp key 1234567890 address 30.1.1.1
crypto isakmp identity hostname
!
crypto ipsec transform-set test-transform ah-md5-hmac esp-des esp-md5-hmac
!
crypto map test-ipsec local-address cable-modem0
crypto map test-ipsec 10 ipsec-isakmp
set peer 30.1.1.1
set transform-set test-transform
match address 200
!
interface Ethernet0
ip address 192.168.100.1 255.255.255.0
no ip directed-broadcast
!
interface cable-modem0
ip address dhcp
no ip directed-broadcast
no keepalive
no cable-modem compliant bridge
crypto map test-ipsec
router rip
version 2
network 10.0.0.0
network 192.168.100.0
!
ip classless
no ip http server

Cisco uBR924 Software Configuration Guide

3-14

OL-0337-05 (8/2002)

Chapter 3

Advanced Data-Only Configurations
IPSec (56-bit) Example

no service finger
!
access-list 200 permit ip host 10.1.0.25 30.1.1.0 0.0.0.255
!
line con 0
exec-timeout 0 0
transport input none
line vty 0 4
login
!
end

Note

The above configuration assumes that the DHCP server assigns an IP address to the cable interface that
is in the class A private network (10.0.0.0).

Additional Documentation
Establishing IPSec encryption between two or more end-points requires a thorough understanding of the
Internet Key Exchange (IKE) mechanism, which is a form of the ISAKMP/Oakley (Internet Security
Association Key Management Protocol) that is used for IPSec encryption. Digital certificates must also
be understood if this mechanism is going to be used for authentication. Finally, if IPSec will be used as
part of a virtual private network (VPN), those concepts must be understood as well.
For general information on these subjects, see the following information in the product literature and IP
technical tips sections on CCO:
•

Deploying IPSec—Provides an overview of IPSec encryption and its key concepts, along with
sample configurations. Also provides a link to many other documents on related topics.

•

Certificate Authority Support for IPSec Overview—Describes the concept of digital certificates and
how they are used to authenticate IPSec users.

•

An Introduction to IP Security (IPSec) Encryption—Provides a step-by-step description of how to
configure IPSec encryption.

The following technical documents, available on CCO and the Documentation CD-ROM, also provide
more in-depth configuration information:

Note

•

Cisco IOS Release 12.1 Security Configuration Guide—Provides an overview of Cisco IOS security
features.

•

Cisco IOS Release 12.0 Security Command Reference—Provides a reference for each of the
Cisco IOS commands used to configure IPSec encryption and related security features.

•

Cisco IOS Software Release 12.1 Command Summary—Summarizes the Cisco IOS commands used
to configure all Release 12.0 security features.

Additional documentation on IPSec becomes available on CCO and the Documentation CD-ROM as new
features and platforms are added.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

3-15

Chapter 3

Advanced Data-Only Configurations

IPSec (3DES) Example

IPSec (3DES) Example
The IPSec 3DES encryption feature set is identical to the IPSec encryption feature set except that it
supports the 168-bit Triple DES (3DES) standard in addition to the standard 56-bit IPSec encryption.
The 168-bit encryption feature set requires a Cisco IOS image that supports it and provides a level of
security suitable for highly sensitive and confidential information such as financial transactions and
medical records.

Note

Cisco IOS images with strong encryption (including, but not limited to, 168-bit [3DES] data encryption
feature sets) are subject to United States government export controls and have limited distribution.
Strong encryption images to be installed outside the United States may require an export license.
Customer orders may be denied or subject to delay due to United States government regulations. When
applicable, the purchaser or user must obtain local import and use authorizations for all encryption
strengths. Contact your sales representative or distributor for more information, or send an e-mail to
export@cisco.com.
Configuration for 3DES encryption is identical to that for standard IPSec, except that the transformation
set should specify esp-3des instead of esp-des. For example, the following configuration is identical to
the configuration shown in “IPSec (56-bit) Example” section on page 3-11, except for the line in bold:
version 12.1
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname Router
!
clock timezone - 0 6
ip subnet-zero
no ip domain-lookup
!
crypto isakmp policy 1
hash md5
authentication pre-share
lifetime 5000
crypto isakmp key 1234567890 address 30.1.1.1
crypto isakmp identity hostname
!
crypto ipsec transform-set test-transform ah-md5-hmac esp-3des esp-md5-hmac
!
crypto map test-ipsec local-address cable-modem0
crypto map test-ipsec 10 ipsec-isakmp
set peer 30.1.1.1
set transform-set test-transform
match address 200
!
interface Ethernet0
ip address 192.168.100.1 255.255.255.0
no ip directed-broadcast
!
interface cable-modem0
ip address dhcp
no ip directed-broadcast
no keepalive
no cable-modem compliant bridge
crypto map test-ipsec
router rip

Cisco uBR924 Software Configuration Guide

3-16

OL-0337-05 (8/2002)

Chapter 3

Advanced Data-Only Configurations
L2TP Example

version 2
network 10.0.0.0
network 192.168.100.0
!
ip classless
no ip http server
no service finger
!
access-list 200 permit ip host 10.1.0.25 30.1.1.0 0.0.0.255
!
line con 0
exec-timeout 0 0
transport input none
line vty 0 4
login
!
end

Note

The above configuration assumes that the DHCP server assigns an IP address to the cable interface that
is in the class A private network (10.0.0.0).

L2TP Example
When the Cisco uBR924 router is using a software image that supports the Layer 2 Tunnel Protocol
(L2TP), the router can function as an L2TP network server (LNS), which is one part of a virtual private
dialup network (VPDN). In this configuration, the router creates a secure connection with another router
that is functioning as an L2TP access concentrator (LAC)—traffic sent between the two routers is
protected from interception or modification, even when it travels across public networks such as the
Internet.

Note

The Cisco uBR924 cable access router does not support the L2TP feature in Cisco IOS Release 12.1(3)T
and above.

Note

The computer connected to the Cisco uBR924 router must be running software, such as Windows 98,
that supports VPDN connections.
Configuration of a VPDN can be very complex, depending on the networks being used and how many
peer devices will be establishing VPDN connections. The following table shows the minimum
configuration needed for a typical VPDN configuration on a Cisco uBR924 router using the L2TP
protocol (the LAC must be similarly configured).

Note

Cisco IOS Release 12.1(5)T, 12.2(2), or greater is required to support GRE IP tunnels.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

3-17

Chapter 3

Advanced Data-Only Configurations

L2TP Example

Command

Purpose

Step 1

uBR924(config)# vpdn enable

Enable VPDN services so that the router will look
for tunnel definitions.

Step 2

uBR924(config)# vpdn-group 1

Create a unique VPDN group (1–3000) to which
VPDN attributes can be assigned, and enter VPDN
configuration mode.

Step 3

uBR924(config-vpdn)# accept dialin l2tp virtual-template Configure the VPDN group to accept a incoming
1 remote L2TP_LAC
request using the L2TP protocol from the remote
peer named L2TP_LAC.

Step 4

uBR924(config-vpdn)# l2tp ip tos reflect

(Optional) Preserve the type of service (TOS) bits in
the original packets.

Step 5

uBR924(config-vpdn)# exit

Return to global configuration mode.

Step 6

uBR924(config)# no l2tp tunnel authentication

Disable L2TP tunnel authentication.

Step 7

uBR924(config)# interface Virtual-Template1

Create a virtual access interface from the virtual
template and enter interface configuration mode.

Step 8

uBR924(config-if)# ip unnumbered Ethernet0

Enable IP traffic on the virtual access interface
without requiring a specific IP address for the
interface.

Step 9

uBR924(config-if)# no ip directed-broadcast

Disable the forwarding of directed broadcasts on
this interface to prevent some common hacker
attacks.

Step 10

uBR924(config-if)# peer default ip address pool dialup

Obtain an IP address from the default dialup IP
address pool.

Step 11

uBR924(config-if)# ppp authentication chap

Enables the Challenge Handshake Authentication
Protocol (CHAP) on the interface to allow
verification of the remote end.

Step 12

uBR924(config-if)# Ctrl-z

Return to privileged EXEC mode.

Step 13

uBR924# copy running-config startup-config
Building configuration...

Save the configuration to nonvolatile memory so
that it will not be lost in the event of a reset, power
cycle, or power outage.

Step 14

uBR924# show startup-config

Display the configuration file that was just created.

Note

For more details on the L2TP feature, see the Layer 2 Tunnel Protocol and L2TP Dialout feature
modules, available on CCO and the Documentation CD-ROM.
The following sections show sample configurations for the Cisco uBR924 router acting as the LNS. The
relevant commands are in bold.
version 12.1
no service pad
service timestamps debug uptime
service timestamps log uptime
!
hostname Router
!
class-map class-default

Cisco uBR924 Software Configuration Guide

3-18

OL-0337-05 (8/2002)

Chapter 3

Advanced Data-Only Configurations
L2TP Example

match any
!
!
clock timezone - 0 1
ip subnet-zero
ip tftp source-interface cable-modem0
no ip domain-lookup
!
vpdn enable
!
vpdn-group 1
accept dialin l2tp virtual-template 1 remote L2TP_LAC
no l2tp tunnel authentication
!
!
interface Ethernet0
ip address 192.168.100.1 255.255.255.0
no ip directed-broadcast
!
interface Virtual-Template1
ip unnumbered Ethernet0
no ip directed-broadcast
peer default ip address pool dialup
ppp authentication chap
!
interface cable-modem0
ip address dhcp
no ip directed-broadcast
no cable-modem compliant bridge
!
router rip
version 2
network 10.0.0.0
network 192.168.100.0
!
ip local pool dialup 192.168.100.100
ip classless
no ip http server
no service finger
!
line con 0
transport input none
line vty 0 4
login
!
end

Note

The above configuration assumes that the DHCP server assigns an IP address to the cable interface that
is in the class A private network (10.0.0.0).

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

3-19

Chapter 3

Advanced Data-Only Configurations

L2TP Example

Cisco uBR924 Software Configuration Guide

3-20

OL-0337-05 (8/2002)

C H A P T E R

Voice over IP Configurations
This chapter provides an overview of Voice over IP (VoIP) operations on the Cisco uBR924 cable access
router. It also describes how to configure the Cisco uBR924 router for basic VoIP operation in both
bridging and routing modes. This chapter contains the following sections:

Note

•

Overview

•

H.323v2 Static Bridging Configuration

•

H.323v2 Static Routing Configuration

•

H.323v2 Dynamic Mapping Configuration

•

SGCP Configuration

•

MGCP Configuration

The configurations shown in this chapter can be combined with most of the data-only configurations
shown in Chapter 3, “Advanced Data-Only Configurations.” All voice configurations assume that the
CMTS and associated servers, gateways, and gatekeepers have been configured accordingly.

Overview
When using a Cisco IOS image that contains voice support, the Cisco uBR924 cable access router
supports Voice over IP (VoIP), which transmits voice and fax calls over a TCP/IP network such as the
Internet. Depending on the services purchased from the cable service provider, subscribers can place and
receive calls without using the local telco exchange carrier.
The Cisco uBR924 router has two voice ports that support two simultaneous voice and fax calls from
each subscriber site, but multiple telephones and fax devices can be connected to each of the two VoIP
telephone lines (provided that the 5 REN limit for each telephone line is not exceeded). Telephones at
each subscriber site must support touch-tone dialing; rotary dialing is not supported. Special telephone
features such as call waiting, forwarding, and conferencing are supported only when using Cisco IOS
images that support those features.

Note

Fax devices—standard Group III and computer-based Group III machines up to 14,400 baud—are
supported in Cisco IOS Release 12.0(5)T and higher images that support VoIP. However, in general,
fax/modem cards are not supported over VoIP links. You must be using a Cisco IOS image that supports
voice and have purchased the appropriate feature license before being able to make voice calls using the
Cisco uBR924 router.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

4-1

Chapter 4

Voice over IP Configurations

Overview

Introduction
The Cisco uBR924 router uses packets to transmit and receive digitized voice over an IP network. Voice
traffic is supported in both the DOCSIS-bridging and routing modes.

Note

When the router is acting in DOCSIS-bridging mode, a voice call originating from the router’s Ethernet
interface cannot terminate on another device attached to that same Ethernet interface; it must terminate
on a device that is reached through the cable interface. The router must be operating in routing mode to
allow calls to both originate and terminate on the Ethernet interface.
Voice signals are packetized and transported in compliance with the following protocols:

Note

•

H.323v2—Second version of an International Telecommunications Union (ITU) standard that
specifies call signaling and control protocols for an IP data network. Supported on Cisco IOS
Release 12.0(4)XI and higher voice images.

•

Simple Gateway Control Protocol (SGCP) Version 1.1—A signaling protocol under review by the
Internet Engineering Task Force (IETF). Supported on Cisco IOS Release 12.0(7)T and higher voice
images.

•

Media Gateway Control Protocol (MGCP) Version 0.1—A proposed IETF voice control protocol
intended to eventually supersede the existing SCGP 1.1 protocol. Supported on Cisco IOS
Release 12.1(3)T and higher voice images.

In Cisco IOS Release 12.1(3)T, the MGCP 0.1 and SGCP 1.1 protocols have been merged on the
Cisco uBR924 router so that the router can respond efficiently to either protocol. The MGCP and SGCP
protocols cannot be used if the H.323v2 protocol is used.
Figure 4-1 illustrates a broadband cable system that supports VoIP transmission.

Cisco uBR924 Software Configuration Guide

4-2

OL-0337-05 (8/2002)

Chapter 4

Voice over IP Configurations
Overview

Figure 4-1

Simplified VoIP Network

Gateway/PSTN
Service
provider
backbone
CMTS rack
equipment

Gatekeeper or
calling agents

Cisco uBR924

Calling party
Residence or SOHO
subscriber site 1

Policy
server

HFC
cable plant

Cisco uBR924

Called party
Residence or SOHO
subscriber site 2

18194

HFC
cable plant

CMTS rack
equipment

The CMTS at the headend routes IP telephony calls from the point of origination to the destination,
transmitting them along with other traffic (both voice and data). To route voice calls across the local IP
network to a destination on the Internet or the public switched telephone network (PSTN), the
Cisco uBR924 router and CMTS deploy IP telephony as a local-loop bypass service. One of the
following routing methods is then used, depending on the protocol being used:
•

If using H.323v2, the Cisco uBR924 acts as the H.323v2 gateway that forwards the voice packets to
the CMTS, which then sends them to a telephony gatekeeper. The gatekeeper transmits the packets
to their ultimate destination.

•

If using SGCP or MGCP, the Cisco uBR924 router acts as the residential gateway that forwards the
voice packets to the CMTS, which then connects to the external call agent (SGCP or MGCP) or
media gateway controller (MGCP). The call agent or controller determines how to transmit the call
across the network to the trunking gateway that will be its ultimate destination.

The gateway at the destination typically interconnects the IP network to the public switched telephone
network (PSTN) so that calls can be made to any phone, not just those that are part of the IP telephony
network.
Voice calls are digitized, encoded, compressed, and packetized in an originating gateway; and then,
decompressed, decoded, and reassembled in the destination gateway. A server maintains subscriber
profiles and policy information. See the Cisco service provider voice documentation set if you have
Cisco gatekeeper, gateway, or other applicable products.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

4-3

Chapter 4

Voice over IP Configurations

Overview

Caution

In certain countries, the provisioning of voice telephony over the Internet or use of these products may
be prohibited and/or subject to laws, regulations or licenses, including requirements applicable to the use
of the products under telecommunications and other laws and regulations; customer must comply with
all such applicable laws in the country where the customer intends to use the product.

Voice Handling
With IP telephony, telephone calls can be delivered at rates as low as 8 kbps in a packet format using
compression algorithms. Depending on the software release used, the Cisco uBR924 cable access router
supports the following algorithms:

Caution

•

G.711 A-Law—64000 bps PCM uncompressed encoding, using the A-Law standard used in most of
the world except for North America and a few other countries.

•

G.711 Mu-Law—64000 bps PCM uncompressed encoding, using the Mu-Law standard used in
North America and a few other countries.

•

G.729—8000 bps compressed CS-ACELP encoding (default for telephone calls).

Because voice is delay-sensitive, a well-engineered network is critical. Fine-tuning your network to
adequately support VoIP typically involves a series of protocols and features geared to support QoS.
To achieve acceptable voice quality and reduce network bandwidth usage, several voice processing
techniques are used. Digital Signal Processors (DSPs) provide the stream-to-packet and
packet-to-stream conversion, as well as voice processing capabilities. Typical voice processing services
include echo cancellation, voice compression, Voice Activity Detection (VAD) or silence compression,
and Dual Tone Multi-Frequency (DTMF) tone detection and generation.

Quality of Service Support
Data traffic typically is sent only on a “best effort” basis, and if a packet is lost or delayed, it can be
easily retransmitted without significantly affecting the connection. Such delays and losses are
unacceptable, however, for real-time traffic such as voice calls.
For this reason, the CMTS and Cisco uBR924 router assign separate service identifiers (SIDs) for the
voice and data traffic flows. Each SID has a separate class of service (CoS) that determines how its traffic
flow is handled, allowing voice traffic to have a higher priority than the data traffic.
The CMTS and router can use different traffic shaping mechanisms to ensure that the higher priority
voice traffic always has the bandwidth it needs. This allows voice calls (and other real-time traffic) to
share the same channel as data traffic, without the quality of the voice calls being degraded by bursty
data transmissions.

Note

Separate CoS flows are available only when the router is connected to a CMTS that supports multiple
classes of service per router. In addition, the router’s configuration file must enable multiple classes of
service.
The DOCSIS 1.0 specification does not support multiple CoS flows, so this flow technique is not

Cisco uBR924 Software Configuration Guide

4-4

OL-0337-05 (8/2002)

Chapter 4

Voice over IP Configurations
Overview

available when the Cisco uBR924 router interoperates with a DOCSIS 1.0 CMTS. In this situation, voice
and data traffic are both transmitted on a “best effort” basis. This may cause poorer voice quality and
lower data throughput when calls are being made from the router’s telephone ports.
The Cisco uBR924 router supports the following service classes:
•

The first CoS in the router’s configuration file is configured as the “Tiered Best Effort Type Class”
and is the default CoS for data traffic. The class has no minimum upstream rate specified for the
channel.
This service class is assigned to the primary SID for the router. In addition to being used for data
traffic, the router uses this SID for all MAC message exchanges with the CMTS, as well as for
SNMP management traffic.
All traffic using this SID is transmitted on a “best effort” basis, but data traffic within this class can
be prioritized into eight different priority levels; although all data traffic still has lower priority than
the voice traffic, this allows certain data traffic (such as MAC messages) to be given higher priority
than other data traffic. The CMTS system administrator defines the traffic priority levels and must
include the traffic priority fields in the configuration file downloaded to the Cisco uBR924.

•

The second and third CoS are for the first and second voice ports, respectively, which are assigned
to the secondary SIDs used for the voice ports. If using a Cisco IOS image that supports dynamic
multi-SID assignment, these secondary SIDs are automatically created when a call is placed from
one of the voice ports; when the call terminates, the secondary SID associated with it is deleted. If
the Cisco IOS image does not support multi-SIDs, static SIDs are created for each of the voice ports
during the power-on provisioning process, permanently reserving the bandwidth needed for the
voice traffic.
The CMTS system administrator typically configures these secondary classes of service so that they
have higher QoS classes for use by higher priority voice traffic. These classes should also have a
minimum upstream data rate specified for the channel to guarantee a specific amount of bandwidth
for the corresponding traffic flows. When static SIDs are used, that bandwidth is always reserved
for voice calls; however, when dynamic multi-SID assignment is used, that bandwidth is reserved
only when the voice calls are active.

H.323v2 Protocol
In architectures using the VoIP H.323v2 protocol stack, the session application manages two call legs
for each call: a telephony leg managed by the voice telephony service provider and the VoIP leg managed
by the cable system operator—the VoIP service provider. Use of the H.323v2 protocol typically requires
a dial plan and mapper at the headend or other server location to map IP addresses to telephone numbers.
When both legs of the call have been setup, the session application creates a conference between them.
The opposite leg’s transmit routine for voice packets is given to each provider. The CMTS router passes
data to the gateway and gatekeeper. The H.323v2 protocol stack provides signaling via H.225 and feature
negotiation via H.245.

Note

For more information on using H.323v2, see the document H.323 Version 2 Support, available on CCO
and the Documentation CD-ROM.
To make and receive H.323 calls, the Cisco uBR924 router must be configured for the following:

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

4-5

Chapter 4

Voice over IP Configurations

Overview

Note

•

The IP address of the gateway for the destination dialed—In Cisco uBR924 IOS Release 12.0(4)XI
or higher interim builds, configure these IP addresses statically via the command-line interface
(CLI) using voip dial peer group commands. When running Cisco IOS Release 12.0(5)T or higher
interim images on Cisco gatekeeper products, the router obtains these addresses dynamically from
the gatekeeper using the Registration, Admission, and Status (RAS) protocol.

•

The telephone numbers of the attached devices—In Cisco IOS Release 12.0(4)XI or higher interim
builds, you configure these IP addresses statically via the CLI pots port commands. When using
Cisco Network Registrar (CNR) version 3.0 or higher with the relay.tcl and setrouter.tcl scripts,
and Cisco gatekeeper products in your network running Cisco IOS Release 12.0(5)T or higher
images, you can obtain these addresses dynamically from CNR. The telephone numbers of attached
devices are then sent in DHCP response messages. When the Cisco uBR924 processes the DHCP
response, it automatically creates the pots dial peer for each port, creates the voip dial peer for the
RAS target, and starts the H.323v2 RAS gateway support.

To support voice configurations involving Cisco gatekeeper products using RAS, Cisco IOS
Release 12.0(5)T or higher images with gatekeeper support are required. The headend must have IP
multicast enabled. The cable interface must be designated as the default for RAS to discover the
gatekeeper. The gatekeeper then resolves all dialed destinations sent to the RAS protocol.

SGCP and MGCP Protocol Stack
When using a Cisco IOS Release 12.0(5)T or higher image with voice support, the Cisco uBR924 router
supports the Simple Gateway Control Protocol (SGCP). When using a Cisco IOS Release 12.1(3)T or
higher image with voice support, the Cisco uBR924 router also supports the MGCP protocol, which is
intended to eventually supersede the SGCP protocol. Both MGCP and SGCP are signaling protocols that
interact with a remote call agent (CA) to provide call setup and teardown for VoIP calls.
Using the call agent, SGCP and MGCP communicate with the voice gateways, dynamically resolving
and routing calls. This creates a distributed system that enhances performance, reliability, and scalability
while still appearing as a single VoIP gateway to external clients.
The remote call agent also provides the signaling and feature negotiation that would otherwise be
provided by the Cisco uBR924 router when using the H.323v2 protocol. Similarly, the call agent also
provides the mapping of IP addresses to telephone numbers, eliminating the dial plan mapper and static
configurations that are required on the router when using the H.323v2 protocol.
The SGCP and MGCP protocols implement the gateway functionality using both trunk and residential
gateways. The Cisco uBR924 router functions in this mode as a residential gateway with two endpoints.
SGCP and MGCP can preserve Signaling System 7 (SS7) style call control information as well as
additional network information such as routing information and authentication, authorization, and
accounting (AAA) security information. SGCP and MGCP allow voice calls to originate and terminate
on the Internet, as well as allowing one end to terminate on the Internet and the other to terminate on a
telephone on the PSTN.

Note

The Cisco uBR924 cable access router supports both H.323 and SGCP/MGCP call control, but only one
method can be active at a time.

Cisco uBR924 Software Configuration Guide

4-6

OL-0337-05 (8/2002)

Chapter 4

Voice over IP Configurations
H.323v2 Static Bridging Configuration

H.323v2 Static Bridging Configuration
When the Cisco uBR924 router is running in DOCSIS-bridging mode and using a Cisco IOS image with
voice support, it can route voice calls using an H.323v2 static dialing map. This requires the following
minimum configuration:
•

Note
•

Create a local dial peer for each voice port that will receive incoming calls. This requires configuring
each voice port on the router with the phone numbers for the devices attached to those voice ports.
The Cisco uBR924 router uses these numbers to determine which voice port should receive the call.
Typically, the complete phone number or extension is specified for each port; when the
Cisco uBR924 router receives an incoming call, all digits in the number are matched and stripped
off, and the voice port is connected to the call.
The voice ports on the Cisco uBR924 router support only FXS devices.
Configure a remote dial peer for each possible destination for outgoing calls. This requires
specifying the phone number(s) for the destination devices. Use the following guidelines for what
numbers to enter:
– For a single telephony device, such as a one-line phone or fax machine, enter the complete

phone number or extension.
– To direct a group of numbers to a specific destination—such as the extensions used on a remote

PBX—enter a pattern matching the prefix used for those lines; asterisks can be used to match
any number of digits and a period matches a single digit. For example, “572*” matches any
phone numbers starting with 572 while “572.” matches the numbers 5720–5729.
You must also specify the IP address for the destination host that will deliver the call to the telephony
device (or if the destination device is an IP telephone, the IP address for that telephone). You can
optionally specify an IP precedence level for the type of service (ToS) bits in the IP header to signify
that these voice packets should be given higher priority in transit across the IP network.
If not being done by the CoS, you can also specify which coding/decoding (CODEC) algorithm
should be used.
These functions are done using the dial-peer command, as shown in the following table:
Command
Step 1

Purpose

To configure incoming calls on voice port V1:

uBR924(config)# dial-peer voice id-number pots

Specify a unique id-number for this incoming
dial-peer and enter dial-peer configuration mode.

Step 2

uBR924(config-dial-peer)# destination-pattern digits

Specify the telephone number(s) associated with this
voice port.

Step 3

uBR924(config-dial-peer)# port 0

Specify that voice port V1 is attached to this
telephony equipment.

Step 4

uBR924(config-dial-peer)# dtmf-relay [cisco-rtp]
[h245-signal] [h245-alphanumeric]

Optionally configure the dial peer to support out of
band signaling of DTMF tones.

Step 5

uBR924(config-dial-peer)# exit
To configure incoming calls on voice port V2:
uBR924(config)# dial-peer voice id-number pots

Exit dial-peer configuration mode.

Step 6

Step 7

uBR924(config-dial-peer)# destination-pattern digits

Specify a unique id-number for this incoming
dial-peer and enter dial-peer configuration mode.
Specify the telephone number(s) associated with this
voice port.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

4-7

Chapter 4

Voice over IP Configurations

H.323v2 Static Bridging Configuration

Command

Purpose

Step 8

uBR924(config-dial-peer)# port 1

Specify that voice port V2 is attached to this
telephony equipment.

Step 9

uBR924(config-dial-peer)# dtmf-relay [cisco-rtp]
[h245-signal] [h245-alphanumeric]

Optionally configure the dial peer to support out of
band signaling of DTMF tones.

Step 10

Exit dial-peer configuration mode.

Step 11

uBR924(config-dial-peer)# exit
Repeat for each possible outgoing destination:
uBR924(config)# dial-peer voice id-number voip

Step 12

uBR924(config-dial-peer)# destination-pattern digits

Specify the telephone number(s) associated with this
dial-peer.

Step 13

uBR924(config-dial-peer)# session target [ ipv4:ipaddress | Specify the destination IP address or hostname for
dns:hostname ]
this dial-peer. This could be the IP address or
hostname for either an IP telephone or another router
or host providing voice services.

Step 14

uBR924(config-dial-peer)# ip precedence number

(Optional) Specify an IP packet precedence level
(1-5) for packets carrying calls to this dial peer (1–5,
where 5 is the highest precedence for normal IP
flows).

Step 15

uBR924(config-dial-peer)# code [ g711alaw | g711ulaw |
g729r8 ]

(Optional) Specify the codec algorithm to be used
for these calls. The default is g711r8 (8Kbps
compression; A-Law and Mu-Law are 64Kbps
compression).

Step 16

uBR924(config-dial-peer)# dtmf-relay [cisco-rtp]
[h245-signal] [h245-alphanumeric]

Optionally configure the dial peer to support out of
band signaling of DTMF tones.

Step 17

uBR924(config-dial-peer)# exit

Exit dial-peer configuration mode.

Step 18

uBR924# copy running-config startup-config
Building configuration...

Save the configuration to nonvolatile memory so
that it will not be lost in the event of a reset, power
cycle, or power outage.

Step 19

uBR924# show startup-config

Display the configuration file that was just created.

Note

Specify a unique id-number for this outgoing
dial-peer and enter dial-peer configuration mode.

The ID numbers assigned using the dial-peer voice command must be unique but they are local to the
Cisco uBR924 router. These numbers are used only when configuring each particular dial peer and have
no meaning when dialing numbers or routing calls.
The following example shows a Cisco uBR924 router set up to support bridging and a static H.323 dial
map with the following characteristics:
•

Voice port V1 is connected to a telephony device that receives calls for the number 4123.

•

Voice port V2 is connected to a telephony device that receives calls for the number 4124.

•

Outgoing calls to the numbers 6000—6999 are routed to the dial peer at IP address 10.1.71.65.

•

Outgoing calls to the numbers 7000—7999 are routed to the dial peer at IP address 10.1.71.75.
These calls are sent with an IP ToS precedence of “5” and using the G.711 Mu-law codec algorithm.

The commands that set up the H.323v2 dial map are shown in bold:
version 12.1
no service pad

Cisco uBR924 Software Configuration Guide

4-8

OL-0337-05 (8/2002)

Chapter 4

Voice over IP Configurations
H.323v2 Static Bridging Configuration

service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname ubr924
!
clock timezone - 3
ip subnet-zero
no ip routing
!
!
voice-port 0
input gain -3
!
voice-port 1
input gain -3
!
dial-peer voice 1 pots
destination-pattern 4123
port 0
!
dial-peer voice 2 pots
destination-pattern 4124
port 1
!
dial-peer voice 1001 voip
destination-pattern 6...
session target ipv4:10.1.71.65
dtmf-relay cisco-rtp h245-signal h245-alphanumeric
!
dial-peer voice 1002 voip
destination-pattern 7...
ip precedence 5
codec g711ulaw
session target ipv4:10.1.71.75
dtmf-relay cisco-rtp h245-signal h245-alphanumeric
!
!
interface Ethernet0
no ip directed-broadcast
no ip route-cache
bridge-group 59
bridge-group 59 spanning-disabled
!
interface cable-modem0
ip address dhcp
no ip directed-broadcast
no ip route-cache
cable-modem downstream saved channel 537000000 26
bridge-group 59
bridge-group 59 spanning-disabled
!
!
ip classless
no ip http server
no service finger
!
!
line con 0
exec-timeout 0 0
transport input none
line vty 0 4
login
end

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

4-9

Chapter 4

Voice over IP Configurations

H.323v2 Static Routing Configuration

H.323v2 Static Routing Configuration
When the Cisco uBR924 router is operating in routing mode, the configuration of an H.323v2 static dial
map uses the same commands as those given in the “H.323v2 Static Bridging Configuration” section on
page 4-7. The only difference is that calls can terminate and originate on the Ethernet interface, which
is not possible in DOCSIS-bridging mode.
The following sample configuration shows a Cisco uBR924 router set up for a static H.323v2 dial map
with the following characteristics:
•

Local dial peer 1 specifies that voice port V1 is connected to a telephone or fax machine with the
number 6101.

•

Local dial peer 2 specifies that voice port V2 is connected to a telephone or fax machine with the
number 6102.

•

Remote dial peer 101 specifies that calls to numbers 6200–6299 should be routed to IP address
10.1.71.62.

•

Remote dial peers 102 and 103 specify that calls to numbers 6101 and 6102 should be routed to IP
address 24.1.61.5, which is the IP address for the Cisco uBR924 router’s Ethernet interface. This
allows the router to complete calls between voice ports V1 and V2.

The commands related to the dial map are in bold.
version 12.1
no service pad
service timestamps debug uptime
service timestamps log uptime
!
hostname ubr924
!
!
!
class-map class-default
match any
!
!
!
clock timezone - 3
ip subnet-zero
!
!
!
!
voice-port 0
!
voice-port 1
!
dial-peer voice 1 pots
destination-pattern 6101
port 0
!
dial-peer voice 2 pots
destination-pattern 6102
port 1
!
dial-peer voice 101 voip
destination-pattern 62..
session target ipv4:10.1.71.62
dtmf-relay cisco-rtp
!
dial-peer voice 102 voip

Cisco uBR924 Software Configuration Guide

4-10

OL-0337-05 (8/2002)

Chapter 4

Voice over IP Configurations
H.323v2 Dynamic Mapping Configuration

destination-pattern 6101
session target ipv4:24.1.61.5
!
dial-peer voice 103 voip
destination-pattern 6102
session target ipv4:24.1.61.5
dtmf-relay cisco-rtp
!
!
interface Ethernet0
ip address 24.1.61.1 255.255.255.0
no ip directed-broadcast
no ip mroute-cache
!
interface cable-modem0
ip address dhcp
no ip directed-broadcast
no ip mroute-cache
cable-modem downstream saved channel 537000000 27
no cable-modem compliant bridge
!
router rip
version 2
network 10.0.0.0
network 24.0.0.0
no auto-summary
!
no ip classless
ip route 0.0.0.0 0.0.0.0 10.1.71.1
no ip http server
no service finger
!
!
line con 0
exec-timeout 0 0
transport input none
line vty 0 4
login
!
!
end

Note

The above configuration assumes that the DHCP server assigns an IP address to the cable interface that
is in the class A private network (10.0.0.0).

H.323v2 Dynamic Mapping Configuration
When using a Cisco IOS image that supports voice, the Cisco uBR924 router supports using the
Registration, Admission, and Status (RAS) protocol to allow a remote gatekeeper to translate phone
numbers (E.164 addresses) to the IP addresses of specific dial peers. This allows the gatekeeper to
maintain a central database of dial peers, so that this information does not have to be entered into static
dial maps on every router that is acting as a voice gateway.

Note

The Cisco uBR924 router can use H.323v2 dynamic mapping in either DOCSIS-bridging mode or
routing mode.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

4-11

Chapter 4

Voice over IP Configurations

H.323v2 Dynamic Mapping Configuration

The example shown in this section assumes that Cisco Network Registrar (CNR) version 3.0 or higher
is being used as the DHCP server. CNR assigns the E.164 addresses to local voice ports and uses DHCP
to define the E.164 addresses-to-port assignments.
The gatekeeper can be a Cisco router, such as the Cisco 3620, with a Cisco IOS image that supports the
gatekeeper function. The Cisco uBR924 router acts as the H.323v2 gateway and creates the dial peers,
starts H.323 RAS gateway support, and registers the E.164 addresses with the gatekeeper. The
gatekeeper resolves the remote peers’ IP addresses when the router sends a request using RAS.

Note

Support for RAS and H.323v2 in Cisco gatekeeper products is found in Cisco IOS Release 12.0(5)T or
higher. Support for multiple classes of service when using Cisco uBR7200 CMTS equipment is found in
Cisco 12.0(4)XI or higher.
If you are not using CNR or Cisco gatekeeper products running Cisco IOS Release 12.0(5)T software,
use a static dial-map as shown in the previous H.323 configurations (“H.323v2 Static Bridging
Configuration” and “H.323v2 Static Routing Configuration”).
You must do the following to configure the Cisco uBR924 router for dynamic mapping:
•

Configure the local dial-peers—This is done in the same way as for a static H.323v2 dial map.

•

Configure the remote dial-peers—This is done in the same way as for a static H.323v2 dial map,
except that instead of specifying a target IP address or host name, you specify ras as the target.

•

Enable the VoIP gateway function using the gateway global configuration command.

•

Configure the cable modem interface to be the gateway interface.

These functions are done using the commands shown in the following table:
Command
To configure incoming calls on voice port V1:
uBR924(config)# dial-peer voice id-number pots

Purpose

Step 2

uBR924(config-dial-peer)# destination-pattern digits

Specify the telephone number(s) associated with this
voice port.

Step 3

uBR924(config-dial-peer)# port 0

Specify that voice port V1 is attached to this
telephony equipment.

Step 4

uBR924(config-dial-peer)# dtmf-relay [cisco-rtp]
[h245-signal] [h245-alphanumeric]

Optionally configure the dial peer to support out of
band signaling of DTMF tones.

Step 5

Exit dial-peer configuration mode.

Step 6

uBR924(config-dial-peer)# exit
To configure incoming calls on voice port V2:
uBR924(config)# dial-peer voice id-number pots

Step 7

uBR924(config-dial-peer)# destination-pattern digits

Specify the telephone number(s) associated with this
voice port.

Step 8

uBR924(config-dial-peer)# port 1

Specify that voice port V2 is attached to this
telephony equipment.

Step 9

uBR924(config-dial-peer)# dtmf-relay [cisco-rtp]
[h245-signal] [h245-alphanumeric]

Optionally configure the dial peer to support out of
band signaling of DTMF tones.

Step 10

uBR924(config-dial-peer)# exit

Exit dial-peer configuration mode.

Step 1

Specify a unique id-number for this incoming
dial-peer and enter dial-peer configuration mode.

Cisco uBR924 Software Configuration Guide

4-12

OL-0337-05 (8/2002)

Chapter 4

Voice over IP Configurations
H.323v2 Dynamic Mapping Configuration

Purpose

Step 11

Command
Repeat for each possible outgoing destination:
uBR924(config)# dial-peer voice id-number voip

Step 12

uBR924(config-dial-peer)# destination-pattern digits

Specify the telephone number(s) associated with this
dial-peer.

Step 13

uBR924(config-dial-peer)# session target ras

Specify that RAS will be used to resolve the
destination for the dial-peer.

Step 14

uBR924(config-dial-peer)# dtmf-relay [cisco-rtp]
[h245-signal] [h245-alphanumeric]

Optionally configure the dial peer to support out of
band signaling of DTMF tones.

Step 15

uBR924(config-dial-peer)# exit

Exit dial-peer configuration mode.

Step 16

uBR924(config)# gateway

Enable the VoIP gateway on the
Cisco uBR924 router.

Step 17

uBR924(config)# interface cable-modem 0

Enter interface configuration mode for the cable
interface.

Step 18

uBR924(config-if)# (enter appropriate cable interface
configuration commands)

Enter whatever commands are needed to configure
the cable interface such as IP address, downstream
channel, whether DOCSIS-bridging is enabled, and
so forth.

Step 19

uBR924(config-if)# h323-gateway voip interface

Specify that the cable interface is the H.323
Gateway VoIP interface.

Step 20

uBR924(config-if)# h323-gateway voip id gatekeeper-id
ipaddr IP-address port-number

Identify the RAS gatekeeper by specifying its
gatekeeper ID (which must match the ID configured
on the gatekeeper), its IP address, and the port
number which services gateway requests.

Step 21

uBR924(config-if)# h323-gateway voip h323-id
interface-id

Specify the H.323 ID for this interface. This ID is
any string that uniquely identifies this gateway to the
gatekeeper. Typically, this is the gateway’s name and
domain (such as “ubr924@cisco.com”).

Step 22

uBR924(config-if)# h323-gateway voip tech-prefix prefix

(Optional) Specify a technology prefix to identify
the type of service this gateway can provide. If more
than one service is being provided, give this
command for each separate technology prefix. (The
prefix is defined at the gatekeeper and can up to 11
characters long, with the pound sign (#) as the last
character.)

Step 23

uBR924(config-if)# exit

Exit interface configuration mode.

Step 24

uBR924# copy running-config startup-config
Building configuration...

Save the configuration to nonvolatile memory so
that it will not be lost in the event of a reset, power
cycle, or power outage.

Step 25

uBR924# show startup-config

Display the configuration file that was just created.

Note

Specify a unique id-number for this outgoing
dial-peer and enter dial-peer configuration mode.

For additional information on the gateway configuration commands, see the document Configuring
H.323 VoIP Gateway for Cisco Access Platforms, available on CCO and the Document CD-ROM.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

4-13

Chapter 4

Voice over IP Configurations

H.323v2 Dynamic Mapping Configuration

The following configuration shows a Cisco uBR924 router configured for routing mode and using RAS
dynamic mapping with the following characteristics:
•

The router’s V1 voice port is connected to a telephone or fax machine with the number 1000, and
the V2 voice port is connected to a telephone or fax machine with the number 1001.

•

Four remote dial-peers are configured, with the numbers 1000, 1001, 2000, and 2001. All use the
G.711 Mu-Law CODEC and the RAS protocol is used to resolve their number-address mapping.
(The local dial-peer numbers, 1000 and 1001 are included as remote dial-peers to allow the router
to forward calls between the two local dial-peers, as well as between local and remote dial-peers;
the router must be in routing mode to support this.)

•

The cable interface is configured as the gatekeeper interface, using the gatekeeper named
gatekeeper3620 at the IP address 10.1.70.50 and at port 1719. The router identifies itself as the
gateway named uBR924 with a tech-prefix of 1#.

The commands related to the dial mapping are in bold.
version 12.1
service config
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname uBR924
!
clock timezone - 4
ip subnet-zero
ip host-routing
!
voice-port 0
!
voice-port 1
!
dial-peer voice 1 pots
destination-pattern 1000
port 0
!
dial-peer voice 2 pots
destination-pattern 1001
port 1
!
dial-peer voice 10 voip
destination-pattern 1001
codec g711ulaw
session target ras
!
dial-peer voice 20 voip
destination-pattern 1000
codec g711ulaw
session target ras
!
dial-peer voice 30 voip
destination-pattern 2000
codec g711ulaw
session target ras
!
dial-peer voice 40 voip
destination-pattern 2001
codec g711ulaw
session target ras
!
gateway

Cisco uBR924 Software Configuration Guide

4-14

OL-0337-05 (8/2002)

Chapter 4

Voice over IP Configurations
SGCP Configuration

!
!
interface Ethernet0
ip address 24.1.0.1 255.255.0.0
no ip directed-broadcast
no ip mroute-cache
!
interface cable-modem0
ip address dhcp
no ip directed-broadcast
no ip mroute-cache
no keepalive
cable-modem downstream saved channel 477000000 56
no cable-modem compliant bridge
h323-gateway voip interface
h323-gateway voip id gatekeeper3620 ipaddr 10.1.70.50 1719
h323-gateway voip h323-id uBR924
h323-gateway voip tech-prefix 1#
!
router rip
version 2
network 10.0.0.0
network 24.0.0.0
!
ip classless
no ip http server
no service finger
!
!
line con 0
transport input none
line vty 0 4
!
end

Note

The above configuration assumes that the DHCP server assigns an IP address to the cable interface that
is in the class A private network (10.0.0.0).

SGCP Configuration
When using Cisco IOS Release 12.0(7)T or higher and a software image that supports voice, the
Cisco uBR924 router can use the SGCP protocol for routing voice calls. This transfers the dial mapping
to an external call agent, so that the VoIP gateways do not have to be individually configured with the
dial mappings.

Note

The Cisco uBR924 router can use SGCP in either DOCSIS-bridging mode or routing mode.
You must do the following to configure the Cisco uBR924 router for a dynamic mapping configuration:
•

Enable SGCP operation on the Cisco uBR924 router.

•

Specify the SGCP call agent’s IP address.

•

Configure the local dial-peers to be SCGP applications.

•

Optionally enable the sending of SNMP traps for SGCP.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

4-15

Chapter 4

Voice over IP Configurations

SGCP Configuration

Note

No configuration of remote dial-peers is needed when using SGCP.
These functions are done using the commands shown in the following table:
Purpose

Step 1

Command
To configure incoming calls on voice port V1:
uBR924(config)# dial-peer voice id-number pots

Step 2

uBR924(config)# application SGCPAPP

Specify that this dial-peer is handled as an SGCP
application.

Step 3

uBR924(config-dial-peer)# destination-pattern digits

Specify the telephone number(s) associated with this
voice port.

Step 4

uBR924(config-dial-peer)# port 0

Specify that voice port V1 is attached to this
telephony equipment.

Step 5

Exit dial-peer configuration mode.

Step 6

uBR924(config-dial-peer)# exit
To configure incoming calls on voice port V2:
uBR924(config)# dial-peer voice id-number pots

Step 7

uBR924(config)# application SGCPAPP

Specify that this dial-peer is handled as an SGCP
application.

Step 8

uBR924(config-dial-peer)# destination-pattern digits

Specify the telephone number(s) associated with this
voice port.

Step 9

uBR924(config-dial-peer)# port 1

Specify that voice port V2 is attached to this
telephony equipment.

Step 10

uBR924(config-dial-peer)# exit

Exit dial-peer configuration mode.

Step 11

ubr924(config)# sgcp

Enable SGCP operations on the router.

Step 12

ubr924(config)# sgcp call-agent ip-address [ port ]

Specify the IP address and optional UDP port
number for the SGCP call-agent. If no port number
is given, the default of 2427 (the well-known SGCP
port number) is used.

Step 13

uBR924(config)# snmp-server enable traps xgcp

(Optional) If SNMP management is used for this
router, specify that SGCP and related traps be sent to
the SNMP manager.

Step 14

uBR924# copy running-config startup-config
Building configuration...

Save the configuration to nonvolatile memory so
that it will not be lost in the event of a reset, power
cycle, or power outage.

Step 15

uBR924# show startup-config

Display the configuration file that was just created.

Specify a unique id-number for this incoming
dial-peer and enter dial-peer configuration mode.

The following configuration shows a Cisco uBR924 router configured in DOCSIS-bridging mode that
uses SGCP for the routing of its voice calls. The relevant commands are shown in bold.
version 12.1
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname ubr924

Cisco uBR924 Software Configuration Guide

4-16

OL-0337-05 (8/2002)

Chapter 4

Voice over IP Configurations
SGCP Configuration

!
!
clock timezone - 0 6
ip subnet-zero
no ip routing
ip domain-name cisco.com
ip name-server 4.0.0.32
!
sgcp
sgcp call-agent 10.186.1.36
!
xgcp snmp sgcp
!
!
voice-port 0
!
voice-port 1
!
dial-peer voice 100 pots
application SGCPAPP
destination-pattern 5551212
port 0
!
dial-peer voice 101 pots
application SGCPAPP
destination-pattern 5551213
port 1
!
process-max-time 200
!
interface Ethernet0
no ip directed-broadcast
no ip route-cache
no ip mroute-cache
bridge-group 59
bridge-group 59 spanning-disabled
!
interface cable-modem0
ip address dhcp
no ip directed-broadcast
no ip route-cache
no ip mroute-cache
cable-modem downstream saved channel 699000000 27
bridge-group 59
bridge-group 59 spanning-disabled
!
ip classless
no ip http server
no service finger
!
!
line con 0
transport input none
line vty 0 4
login
!
end

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

4-17

Chapter 4

Voice over IP Configurations

MGCP Configuration

MGCP Configuration
When using Cisco IOS Release 12.1(3)T and higher software images that support voice, the
Cisco uBR924 router can use the MGCP protocol for routing voice calls. This transfers the dial mapping
to an external call agent or to a Media Gateway Controller, so that the VoIP gateways do not have to be
individually configured with the dial mappings.

Note

The Cisco uBR924 router can use MGCP in either DOCSIS-bridging mode or routing mode.
You must do the following to configure the Cisco uBR924 router for MGCP routing of voice calls:

Note

•

Enable MGCP operation on the Cisco uBR924 router.

•

Specify the MGCP call agent’s IP address.

•

Configure the local dial-peers to be MCGP applications.

•

Optionally specify the MGCP packages to be supported.

•

Optionally change a number of MGCP parameters.

No configuration of remote dial-peers is needed when using MGCP.
These functions are done using the commands shown in the following table:
Purpose

Step 1

Command
To configure incoming calls on voice port V1:
uBR924(config)# dial-peer voice id-number pots

Step 2

uBR924(config)# application MGCPAPP

Specify that this dial-peer is handled as an MGCP
application.

Step 3

uBR924(config-dial-peer)# port 0

Specify that voice port V1 is attached to this
telephony equipment.

Step 4

Exit dial-peer configuration mode.

Step 5

uBR924(config-dial-peer)# exit
To configure incoming calls on voice port V2:
uBR924(config)# dial-peer voice id-number pots

Step 6

uBR924(config)# application MGCPAPP

Specify that this dial-peer is handled as an MGCP
application.

Step 7

uBR924(config-dial-peer)# port 1

Specify that voice port V2 is attached to this
telephony equipment.

Step 8

uBR924(config-dial-peer)# exit

Exit dial-peer configuration mode.

Step 9

ubr924(config)# mgcp

Enable MGCP operations on the router.

Step 10

ubr924(config)# mgcp call-agent ip-address [ port ]
[ service-type sgcp | mgcp ]

Specify the IP address and optional UDP port
number for the MGCP call-agent. If no port number
is given, the default is 2427. The default
service-type is mgcp, but sgcp can be specified to
ignore RSIP error messages.

Specify a unique id-number for this incoming
dial-peer and enter dial-peer configuration mode.

Cisco uBR924 Software Configuration Guide

4-18

OL-0337-05 (8/2002)

Chapter 4

Voice over IP Configurations
MGCP Configuration

Command

Purpose

Step 11

ubr924(config)# mgcp dtmf-relay { codec | low-bit-rate }
mode { cisco | out-of-band }

(Optional) Enables the accurate forwarding of
touchtone digits during a voice call. Use codec to
specify the G.711 codec or low-bit-rate to specify
the G.729 codec. Use a mode of cisco to transmit the
tones with the Cisco proprietary method; if the
remote gateway is not a Cisco router, use
out-of-band instead.

Step 12

ubr924(config)# mgcp ip-tos { high-reliability |
high-throughput | low-cost | low-delay | precedence
value }

(Optional) Enable IP Type of Services (TOS) for the
voice connections, and specify the value for the IP
precedence bit (the default IP precedence is 3).

Step 13

ubr924(config)# mgcp max-waiting-delay value

(Optional) Specify the number of milliseconds to
wait after a restart (default of 3000) before
connecting with the call agent. If used, these values
should be staggered among gateways to avoid
having large numbers of gateways connecting with
the call agent at the same time after a mass restart.

Step 14

ubr924(config)# mgcp modem passthru { cisco | ca }

(Optional) Enable the transmission and reception of
modem and fax data. If the remote gateway is a
Cisco router, specify cisco; otherwise, specify ca
(default) to allow the data to pass-through the
call-agent.

Step 15

ubr924(config)# mgcp package-capability { line-package | (Optional) Specify that the Cisco uBR924 router
dtmf-package | gm-package | rtp-package }
supports a particular package capability. Give this
command multiple times to enable multiple
packages. Use this command before using the mgcp
default-package command.

Step 16

ubr924(config)# mgcp default-package { line-package |
dtmf-package | gm-package }

(Optional) Specify the default package type for the
media gateway; defaults to line-package.

Step 17

ubr924(config)# mgcp playout { adaptive init-value
min-value max-value | fixed init-value }

(Optional) Change the jitter buffer packet size in
milliseconds for MGCP calls, using either an
adaptive range or a fixed value. The default is
adaptive 60 4 200.

Step 18

ubr924(config)# mgcp request retries count

(Optional) Specify the number of times a call
request message is transmitted to a call agent before
timing out. The default is 3 times.

Step 19

ubr924(config)# mgcp request timeout timeout

(Optional) Specify the number of milliseconds to
wait for a response to a request before retransmitting
or timing out the request. The default is 500
milliseconds.

Step 20

ubr924(config)# mgcp restart-delay value

(Optional) Specify the value (in seconds) used in
Restart in Progress (RSIP) messages to indicate the
delay before the connection is torn down. The
default delay is 0 seconds.

Step 21

ubr924(config)# mgcp vad

(Optional) Enable Voice Activity Detection (VAD)
to turn silence suppression on. The default disables
VAD.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

4-19

Chapter 4

Voice over IP Configurations

MGCP Configuration

Command

Purpose

Step 22

uBR924# copy running-config startup-config
Building configuration...

Save the configuration to nonvolatile memory so
that it will not be lost in the event of a reset, power
cycle, or power outage.

Step 23

uBR924# show startup-config

Display the configuration file that was just created.

The following configuration shows a Cisco uBR924 router configured in DOCSIS-bridging mode that
uses MGCP for controlling its voice calls. The relevant commands are shown in bold.
version 12.1
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname ubr924
!
!
clock timezone - 0 6
ip subnet-zero
no ip routing
ip domain-name cisco.com
ip name-server 10.0.0.32
!
mgcp
mgcp call-agent 10.186.1.36
mgcp modem passthru ca
mgcp package-capability dtmf-package
mgcp package-capability line-package
mgcp default-package line-package
!
xgcp snmp sgcp
!
!
voice-port 0
!
voice-port 1
!
dial-peer voice 100 pots
application MGCPAPP
port 0
!
dial-peer voice 101 pots
application MGCPAPP
port 1
!
process-max-time 200
!
interface Ethernet0
no ip directed-broadcast
no ip route-cache
no ip mroute-cache
bridge-group 59
bridge-group 59 spanning-disabled
!
interface cable-modem0
ip address dhcp
no ip directed-broadcast
no ip route-cache
no ip mroute-cache
bridge-group 59

Cisco uBR924 Software Configuration Guide

4-20

OL-0337-05 (8/2002)

Chapter 4

Voice over IP Configurations
MGCP Configuration

bridge-group 59 spanning-disabled
!
ip classless
no ip http server
no service finger
!
!
line con 0
transport input none
line vty 0 4
login
!
end

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

4-21

Chapter 4

Voice over IP Configurations

MGCP Configuration

Cisco uBR924 Software Configuration Guide

4-22

OL-0337-05 (8/2002)

A P P E N D I X

Using Cisco IOS Software
This appendix describes the basics about using the Cisco IOS software that is installed on every
Cisco uBR924 cable access router. This appendix describes the following topics:

Caution

•

Accessing the Router’s Command-Line Interface

•

Understanding the Command-Line Interface

•

Understanding Cisco IOS Configuration Files

•

Useful Commands

Before attempting to reconfigure the Cisco uBR924 cable access router at a subscriber site, contact your
provisioning or billing system administrator to ensure remote configuration is allowed. To ensure proper
levels of service for all customers, service providers typically disable remote configuration of the cable
modems on their system and allow only the configuration that is specified by the cable provisioning or
billing system.
If remote configuration is disabled, any changes you make do not remain in effect after the
Cisco uBR924 router is powered off and on. Instead, the router returns to its previous configuration. In
some cases, these settings will cause the cable interface to disconnect and may be lost when the cable
interface is reset.

Accessing the Router’s Command-Line Interface
The Cisco uBR924 router’s command-line interface (CLI) can be accessed either through a Telnet
connection over a TCP/IP network or by a direct connection to the router’s console port. See the
following sections for more information.

Note

The Cisco uBR924 router also supports accessing the CLI through the Cisco web server, but this feature
is automatically disabled when the Cable Monitor is active. See Appendix B, “Using the Cable Monitor
Tool” for details.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

A-1

Appendix A

Using Cisco IOS Software

Accessing the Router’s Command-Line Interface

Connecting Using Telnet
If the Cisco uBR924 router has successfully booted up and is operational and online, its CLI interface
can be accessed by establishing a Telnet connection. Telnet can be used from any computer or terminal
that has TCP/IP connectivity with the Cisco uBR924 router—the TCP/IP connectivity can exist either
through the Ethernet interface or the cable interface.

Note

As a security measure, you can enter EXEC mode during a Telnet session only if an enable password has
been set on the router. If an enable password has not been set, you can only display the current
configuration when you log in using Telnet; to change the configuration you must log in through the
router’s console port.

Caution

Care must be taken if you use a laptop computer to make a Telnet connection through the Cisco uBR924
router’s Ethernet interface, either by connecting the laptop directly to one of the router’s Ethernet ports
or by connecting the laptop to a hub that is connected to one of the router’s Ethernet ports. If the laptop
computer will not be regularly used at the subscriber site, you should power cycle the Cisco uBR924
router after you use the CLI and save your configuration changes.
Power cycling the Cisco uBR924 router ensures the laptop computer does not remain in the router’s list
of allowable Customer Premises Equipment (CPE) devices at the subscriber site. Reinitialization of the
cable interface clears out the bridge table and resets the counter that specifies the number of CPE devices
being bridged. This is particularly important when the Cisco uBR924 router is configured to operate in
a DOCSIS-compliant bridging mode.
If the headend is a Cisco uBR7200 series universal broadband router, the system administrator at the
headend might have to issue the clear cable modem host mac address command to remove the laptop
computer from its list of CPE devices.
This behavior is required by the DOCSIS 1.0 specification.

Connecting to the Console Port
The router’s CLI is available by connecting directly to the console port on the back panel of the router.
The console port is an EIA/TIA-232 serial interface configured as data communications equipment
(DCE) and uses an RJ-45 connector. The port is wired the same as Cisco’s other routers and uses the
same console kit and cable.
The console port can be accessed by any computer or terminal with an RS-232 serial port set for 9600
baud, 8 data bits, no parity, 1 stop bit (9600 8N1). Unless the router’s default configuration has been
changed, your terminal software should be set to emulate an ANSI, VT100, or compatible terminal.

Note

Typically, the console port is disabled when the CMTS downloads a Cisco IOS configuration file to the
router. If this is the case, the CLI can be accessed only through a Telnet connection.

Cisco uBR924 Software Configuration Guide

A-2

OL-0337-05 (8/2002)

Appendix A

Using Cisco IOS Software
Understanding the Command-Line Interface

Understanding the Command-Line Interface
The Cisco IOS command-line interface (CLI) is a text-based interface available on every Cisco router
that uses the Cisco IOS software. This allows a network administrator to quickly configure any of
Cisco’s many different models of routers without having to learn a unique interface for each.
The following guidelines apply to the CLI:
•

The CLI is case-insensitive—for example, you can enter either SHOW VERSION or show version
to display the Cisco uBR924 router’s software revision.

•

You can abbreviate commands and keywords to the minimum number of characters that define a
unique abbreviation. For example, you can abbreviate the show command to sh (but you cannot
abbreviate the show command to just s because several other commands also start with the letter s).

•

If you enter an unrecognized command, the router assumes the command is actually the host name
of a PC or other router and tries to open a Telnet connection to it. If the router cannot find that host,
the connection will eventually time out and the CLI prompt will be redisplayed.

•

By default, if a command displays more than one screen of data, it pauses the screen and displays
--More-- at the bottom of the screen. You can advance one line at a time by pressing the Return key,
advance one screen at a time by pressing the spacebar, or quit by pressing q.

•

As a general rule, every configuration command can be disabled by prefixing the command with the
keyword no. For example, IP routing is enabled with the ip routing command; IP routing is disabled
with the no ip routing command.

•

The CLI on the Cisco uBR924 router can be accessed either through a Telnet connection or through
a serial connection with its console port. (Web browser access to the CLI is not supported on the
Cisco uBR924 router when the Cable Monitor is active.)

These additional topics are covered in the sections that follow:
•

The CLI contains many different command modes that allow access to different areas of the
Cisco uBR924 router’s configuration. Certain commands are available only in a specific command
mode. See “Command Modes” section on page A-3.

•

The question mark character (?) displays a list of the available commands and can be used to display
help about a specific command. See “Context-Sensitive Help” section on page A-6.

•

You can use the command history feature to quickly recall and edit previous commands. See
“Command History Features” section on page A-7.

•

When commands produce long displays, you can use output modifiers to select which parts of the
display you want to see. See “Using Output Modifiers” section on page A-8.

Command Modes
The Cisco IOS software has many different modes of operation—each mode contains its own set of
commands that either display or configure a particular aspect of the Cisco uBR924 router’s
configuration. When you initially log in to the Cisco uBR924 router, you enter user EXEC mode, which
provides a limited number of commands that can only display information about the router; you cannot
change the router’s configuration in user EXEC mode.
To change the router’s configuration, you must enter privileged EXEC mode or one of the other
configuration modes. Each command mode has a unique prompt so that you can easily see which mode
you are in.
Table A-1 shows the most common modes that are used on the Cisco uBR924 router:

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

A-3

Appendix A

Using Cisco IOS Software

Understanding the Command-Line Interface

Table A-1

Cisco uBR924 Router Command Modes

Command
Mode

Function

Access Method

Prompt1

User EXEC

Contains a limited number of commands that only display Log in.
information about the Cisco uBR924 router.

Router>

Privileged
EXEC

Contains a larger number of display commands, as well as From user EXEC mode,
other commands that can change the configuration of the enter the enable
command.
router. Also provides access to the global configuration
mode.

Router#

Global
configuration

Contains commands that can change the operation of the From privileged EXEC
Router(config)#
Cisco uBR924 router at a system level and provides access mode, enter the configure
to the interface configuration mode.
terminal command.

Interface
configuration

Contains commands that change the operation of the
router’s Ethernet and cable interfaces.

From global configuration Router(config-if)
mode, enter the interface #
interface-num command.

1. The prompt always displays the router’s hostname. The default hostname is “Router” but this can be changed with the global configuration hostname
command.

Table A-1 lists the command modes in the order they must be accessed. You must log in to a higher-level
mode before accessing the next lower mode. For example, before you can enter global configuration
mode, you must first log in to user EXEC mode and then privileged EXEC mode. Then you can enter
global configuration mode, and if desired, log in to interface configuration mode.
To leave a command mode and return to the previous mode, enter either the exit or end command. See
the following sections for more details on each command mode.

Note

For complete information on using the CLI, see the Configuration Fundamentals Configuration Guide,
available on CCO and the Documentation CD-ROM.

User EXEC Mode
When you log in to the Cisco uBR924 router, you automatically enter the user EXEC command mode,
which contains commands that only display some parts of the router’s configuration. In general, user
EXEC commands allow you to connect to remote devices, change terminal settings on a temporary basis,
perform basic tests, and list system information.
The user-level prompt consists of the router’s name followed by a right angle bracket (>):
Router>

To leave user EXEC mode and log out of the Cisco uBR924 router, enter the logout or exit command.

Privileged EXEC Mode
Before you can enter any commands that change the Cisco uBR924 router’s configuration, you must
enter privileged EXEC mode. In this mode you can change certain router parameters, use more detailed
show commands, and other configuration modes to change the operation of the router and its interfaces.

Cisco uBR924 Software Configuration Guide

A-4

OL-0337-05 (8/2002)

Appendix A

Using Cisco IOS Software
Understanding the Command-Line Interface

To access the privileged EXEC mode, enter the enable command from user EXEC mode. You are then
prompted for a password, if one has been set for the privileged EXEC mode. The password is not
displayed on the screen and is case sensitive. The prompt changes to the router’s host name followed by
the pound sign (#) to indicate you are now in privileged EXEC mode.

Note

If an enable password has not been set, privileged EXEC mode can be accessed only from the router
console, not through a Telnet connection.
The following example shows how to access privileged EXEC mode:
Router> enable
Password:
Router#

To return from privileged EXEC mode to user EXEC mode, use the disable or exit command.

Global Configuration Mode
The global configuration mode contains commands that change configuration parameters that affect the
operation of the entire Cisco uBR924 router, such as routing and bridging functions, as opposed to
changing the operation of a single interface. To log in to global configuration mode, enter the configure
terminal from privileged EXEC mode. The prompt changes to the router’s host name followed by
“(config)#” to indicate you are now in global configuration mode.
The following example shows how to access global configuration mode:
Router# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#

To exit global configuration mode and return to privileged EXEC mode, enter the exit or end command,
or type Ctrl-Z.

Interface Configuration Mode
The interface configuration mode configures features for an individual interface. The
Cisco uBR924 cable access router supports the following interfaces:
•

Ethernet0—Ethernet interface on the back panel of the router

•

cable-modem0—Cable interface that connects to the cable network

•

Loopback0—Internal interface used primarily for debugging

To log in to interface configuration mode, enter the interface command followed by the name of the
interface to be configured. The prompt changes to the router’s host name followed by “(config-if)#” to
indicate you are now in interface configuration mode.
For example, to configure the cable interface on the Cisco uBR924 router, enter the following commands
from global configuration mode:
Router(config)# interface cable-modem 0
Router(config-if)#

To exit interface configuration command mode and return to global configuration mode, enter the exit
command, or type Ctrl-Z.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

A-5

Appendix A

Using Cisco IOS Software

Understanding the Command-Line Interface

Context-Sensitive Help
The Cisco IOS CLI contains a context-sensitive help feature that can display a list of the commands that
are available for the current command mode. The context-sensitive help can also display the syntax for
a particular command, as well as complete a partially entered command.
Table A-2 shows the different ways you can access the context-sensitive help:
Table A-2

Context-Sensitive Help for the Command -Line Interface

Command

Purpose

help

Obtain a brief description of the help system in any command mode.

List all commands available for a particular command mode.

partial-command?

Obtain a list of commands that begin with a particular character string. (Do
not enter a space before the question mark.)

partial-command Complete a partial command name. (Do not enter a space before entering
the tab character.)
command ?

List a command’s associated keywords. (A space must precede the question
mark.)

command keyword ?

List a keyword’s associated arguments. (A space must precede the question
mark.)

The context-sensitive help displays only the commands and options that are appropriate for the current
command mode. For example, to display the available show commands in the user EXEC mode, enter
show ? as shown in the following example:
ubr924> show ?
backup
bootflash:
call
cca
class-map
clock
compress
dial-peer
dialer
exception
flash:
gateway
history
hosts
location
num-exp
policy-map
ppp
queue
queueing
radius
rmon
sessions
sgcp
snmp
template
terminal
traffic-shape

Backup status
display information about bootflash: file system
Show Calls
CCA information
Show QoS Class Map
Display the system clock
Show compression statistics
Dial Plan Mapping Table for, e.g. VoIP Peers
Dialer parameters and statistics
exception informations
display information about flash: file system
Show status of gateway
Display the session command history
IP domain-name, lookup style, nameservers, and host table
Display the system location
Number Expansion (Speed Dial) information
Show QoS Policy Map
PPP parameters and statistics
Show queue contents
Show queueing configuration
Shows radius information
rmon statistics
Information about Telnet connections
Display Simple Gateway Control Protocol information
snmp statistics
Template information
Display terminal configuration parameters
traffic rate shaping configuration

Cisco uBR924 Software Configuration Guide

A-6

OL-0337-05 (8/2002)

Appendix A

Using Cisco IOS Software
Understanding the Command-Line Interface

translation-rule
users
version
voice
ubr924>

Show translation rule table
Display information about terminal lines
System hardware and software status
Voice port configuration & stats

Entering the same help command in privileged EXEC or global configuration mode would display a
different list of show commands. The following shows how to display a list of available commands that
start with “t”:
ubr924> t?
telnet terminal
ubr924>

traceroute

tunnel

Command History Features
The CLI command history feature remembers the commands that you have entered during the current
session. You can use this feature to repeat or change previous commands without retyping them. See the
following sections for more information.

Displaying the Command History
To recall commands from the history buffer, use one of the commands shown in Table A-3.
Table A-3

Recalling Previous Commands

Command

Purpose

Press Ctrl-P or the up arrow key.

Recall commands in the history buffer, beginning with the most
recent command. Repeat to recall successively older commands.

Press Ctrl-N or the down arrow
key.1

Return to more recent commands in the history buffer after
recalling commands with Ctrl-P or the up arrow key. Repeat to
recall successively more recent commands.

show history

List the last several commands you have just entered (user EXEC
mode only).

1. The arrow keys function only on ANSI-compatible terminals such as VT100s.

Editing Previous Commands
When you display a previous command using Ctrl-P or Ctrl-N, you can edit that command to correct
any errors or to change a parameter. This allows you to quickly give a series of similar commands
without having to retype each command.
Table A-4 shows the most commonly used editing commands.
Table A-4

Editing Previous Commands

Command1

Purpose

Press Ctrl-A

Move to the beginning of the line.

Press Ctrl-B

Move back one character.

Press -B

Move back to the previous word.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

A-7

Appendix A

Using Cisco IOS Software

Understanding the Command-Line Interface

Table A-4

Editing Previous Commands

Command1

Purpose

Press Ctrl-D

Delete the character at the cursor position.

Press Ctrl-E

Move to the end of the line.

Press Ctrl-F

Move forward one character.

Press -F

Move forward one word.

Press Ctrl-K

Delete all characters from the cursor to the end of the line.

Press Ctrl-U or Ctrl-X

Delete all characters from the cursor to the beginning of the line.

Press Ctrl-W

Delete a single word.

1. These editing commands are similar to those used in the EMACS text editor.

Note

Additional editing commands are given in the Configuration Fundamentals Configuration Guide,
available on CCO and the Documentation CD-ROM.

Command History Buffer Size
By default, the command history feature stores the 10 most recent commands in its history buffer. You
can change the size of this buffer for the current terminal session with the terminal history command:
ubr924> terminal history size 20
ubr924>

The terminal no history size command resets the number of lines saved in the history buffer to the
default of 10 lines.

Using Output Modifiers
Many of the Cisco uBR924 router’s commands output a great deal of information that takes many
screens to display. You can use the Cisco IOS software’s output modifiers to filter the output of almost
any command, so that you can display only those lines you are interested in.
The output modifier feature is invoked by using the pipe symbol (|). To use this feature, enter a command
as normal but add a space and the pipe symbol at the end of the command line. Then add one of the
keywords
Table A-5

Using Output Modifiers

Command

Purpose

begin regular expression

Display the first line that matches the regular expression and
then all other lines that follow that line.

include regular expression

Display all lines that match the regular expression.

exclude regular expression

Display all lines except those that match the regular expression.

The following example shows how the output from the show ip traffic command is filtered to display
only those lines that include the word “error”:

Cisco uBR924 Software Configuration Guide

A-8

OL-0337-05 (8/2002)

Appendix A

Using Cisco IOS Software
Understanding Cisco IOS Configuration Files

ubr924>show ip traffic | include error
0 format errors, 0 checksum errors, 1 bad hop count
Rcvd: 0 format errors, 0 checksum errors, 0 redirects, 4 unreachable
Total: 0/0, 0 checksum errors, 0 format errors
Total: 0/0, Format errors: 0/0, Checksum errors: 0/0
Rcvd: 134 total, 0 checksum errors
Rcvd: 23 total, 0 checksum errors, 9 no port
Rcvd: 17 total, 0 checksum errors, 1 no port

Understanding Cisco IOS Configuration Files
Cisco IOS configuration files are text files that contain Cisco IOS commands to configure the
Cisco uBR924 router when it boots up and is first configured. These commands are the same commands
that could be given manually at the router’s CLI interface; however, putting them in a configuration file
avoids having to retype them whenever the router is reset.

Downloading the Configuration File
Usually, the Cisco IOS configuration file is specified as part of the DOCSIS configuration file. In this
situation, the service provider creates and maintains both the DOCSIS and Cisco IOS configuration files
for the routers, and those files are stored on TFTP servers located at the provider’s headend plant.
The Cisco uBR924 router automatically loads the DOCSIS configuration file when it is connected to a
cable network and powered on. If the DOCSIS configuration file specifies that a Cisco IOS configuration
file is to be loaded, the router uses the TFTP protocol to download that file and then executes the file so
that the non-DOCSIS routing and interface parameters are correctly configured.
When the DOCSIS configuration file specifies that a Cisco IOS configuration file should be downloaded,
the Cisco uBR924 router automatically takes the following steps to ensure that the configuration cannot
be changed by the user at the remote site:
1.

Terminates any current Telnet sessions.

Disables console access.

Deletes the current Cisco IOS configuration, if any.

Downloads the Cisco IOS configuration file.

After configuring itself according to the commands in the Cisco IOS configuration file, the router
comes online and starts sending traffic.

If the DOCSIS configuration file does not specify that a Cisco IOS configuration file should be loaded,
the network administrator can log in to the router’s CLI interface and manually load the file using the
copy tftp command. (In this situation, console access is not disabled, allowing users at the remote site
to modify the configuration if desired.)

Note

The DOCSIS configuration file is a binary file that must be in the specific format given by the DOCSIS
1.0 specification; it configures DOCSIS and cable-related parameters. The Cisco IOS configuration file
is a text file that can be in any arbitrary format, as long as the lines in that file contain valid commands
that could be given at the router’s CLI interface. Typically, the Cisco IOS configuration file sets routing
parameters and whatever other parameters are needed for special feature sets, such as the voice over IP
(VoIP) or firewall features.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

A-9

Appendix A

Using Cisco IOS Software

Understanding Cisco IOS Configuration Files

Startup and Run-Time Configuration Files
The startup configuration file is a Cisco IOS configuration file stored in the router’s non-volatile Flash
memory and is automatically run whenever the router is reset or powered-on. When a DOCSIS
configuration file specifies that a Cisco IOS configuration file should be downloaded, that Cisco IOS
configuration file automatically becomes the startup configuration file.
The run-time configuration file is the Cisco IOS configuration file that the router is currently using as it
operates. When a router is first powered-on or reset, the run-time configuration file is the same as the
startup configuration file.
However, when you make configuration changes to the router, either by using the CLI or by using SNMP
commands, the run-time configuration file is updated with those changes. Over time, the run-time
configuration file has a different configuration than the startup configuration file. Resetting the router
automatically erases the run-time configuration and restores the startup configuration.
If you want to save your changes to the router’s configuration, you must save the run-time configuration
as the startup configuration file. To do so, enter the following global configuration command:
copy running-config startup-config

Note

Any changes you make to either the startup or run-time configuration are automatically overwritten
when the router is rebooted if the DOCSIS configuration file specifies that a new Cisco IOS
configuration file must be downloaded from the TFTP server. If this is the case, you must also manually
update the Cisco IOS configuration file on the TFTP server to preserve any configuration changes you
make.
To restore the startup configuration without resetting the router, give the following global configuration
command:
copy startup-config running-config

Displaying the Configuration Files
The startup and run-time configuration files can be displayed with the following global configuration
commands:
show startup-config
show running-config

The Cisco uBR924 router displays the appropriate configuration file in a format that you can capture and
save on a TFTP server so it can be downloaded to another router.

Note

The configuration files do not contain any commands that restore the router to its default values. For
example, if you enable IP routing with the “ip routing” command, this is not saved in the configuration
files because this is the default configuration. However, if you disable IP routing with the “no ip
routing” command, this is saved in the configuration file.
The show command uses exclamation marks (!) to create blank lines as spacers. These extra lines do not
affect the functionality of the router but exist only to make the configuration files more readable.

Cisco uBR924 Software Configuration Guide

A-10

OL-0337-05 (8/2002)

Appendix A

Using Cisco IOS Software
Useful Commands

File Format
The Cisco IOS configuration file is an ASCII text file that contains any Cisco IOS configuration
commands to configure the Cisco uBR924 router. The router is automatically put into the global
configuration mode when the file is executed, but if you use any commands for any other command
modes, you must give the appropriate global configuration command to enter that other command mode
first.
For example, to configure the cable interface on the Cisco uBR924 router, you must first enter interface
mode with the following command:
interface cable 0

You can use exclamation marks (!) to create comments and blank lines in your own configuration files.
These comments and blank lines are not preserved when the file is loaded into the router. However, they
are useful for communicating information to other administrators who might be working with the files
on the TFTP server.

Useful Commands
Table A-6 lists some of the most commonly used commands for the Cisco uBR924 router.
Table A-6

Useful Commands

Command

Command Mode

Purpose

banner

global
configuration

Displays and configures the login banners that
appears when a user first logs in and when a user
moves to a different command mode.

configure terminal

user EXEC

Enters global configuration mode.

copy startup-config
running-config

global
configuration

Configures the router with its boot-up
configuration file.

enable

user EXEC

Enters privileged EXEC mode.

exit

all modes

Leaves the current command mode and returns to
the next higher level. If currently in user EXEC
mode, logs you out of the router.

hostname

global
configuration

Sets the router’s hostname.

logout

user EXEC

Logs out of user EXEC mode and the
Cisco uBR924 router.

show flash

user EXEC

Displays the content of the router’s Flash
memory, which contains the Cisco IOS software
image that was loaded.

show history

user EXEC

Displays the most recently entered commands.

show interfaces

user EXEC

Displays the configuration and status of each of
the router’s interfaces.

show ip arp

user EXEC

Displays the contents of the router’s current
Address Resolution Protocol (ARP) table.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

A-11

Appendix A

Using Cisco IOS Software

Useful Commands

Table A-6

Useful Commands (continued)

Command

Command Mode

Purpose

show ip dhcp server statistics user EXEC

Displays the contents of the router’s DHCP
database.

show ip interface

user EXEC

Displays the IP configuration and status for the
router’s Ethernet and cable interfaces.

show ip protocols

user EXEC

Displays the IP routing protocol parameters and
status.

show ip rip database

user EXEC

Displays the contents of the Routing Information
Protocol (RIP) database.

show ip route

user EXEC

Displays the contents of the router’s current IP
routing table.

show ip traffic

user EXEC

Displays statistics for the IP traffic sent through
the router.

show protocols

user EXEC

Displays the currently configured protocols for
each interface.

show running-config

privileged EXEC Displays the active configuration.

show startup-config

privileged EXEC Displays the configuration loaded into the router
at boot-up.

show version

user EXEC

Displays the Cisco uBR924 software and
hardware versions.

Cisco uBR924 Software Configuration Guide

A-12

OL-0337-05 (8/2002)

A P P E N D I X

Using the Cable Monitor Tool
This appendix describes the Cisco uBR924 cable access router’s Cable Monitor tool. The Cable Monitor
is part of the router’s onboard software that provides a web-based diagnostic tool for easy access to
configuration and status information about the router, without requiring access to the router’s command
line interface (CLI).

Note

The Cable Monitor is available in Cisco IOS Release 12.1(1)T and later releases.
Technicians and subscribers can access the tool in the following ways:
•

When the Cisco uBR924 router has established connectivity with the CMTS over the cable interface,
a service technician can use a web browser to remotely access the router and display the desired
information.

•

When the cable network is not operational and the Cisco uBR924 router is not online, the subscriber
can access the tool with a PC connected to the router’s Ethernet ports. Technicians can then prompt
the user for the information they need to determine the source of the problem.

The Cable Monitor operates in two modes:

Note

•

Basic Mode—In basic mode, the Cable Monitor displays the current LED colors and status, as well
as the results of the router’s initialization routines (its power-on self-tests and its registration with
the CMTS). This provides a quick status check of the router, as well as what stage of the
initialization process is failing (if any).

•

Advanced Mode—In advanced mode, the Cable Monitor also displays status and configuration
information about the router’s voice ports, the DOCSIS MAC layer, and cable interface, as well as
performance statistics. Technicians with the proper login ID and password can also display
advanced debug information that collects the output of the most commonly used troubleshooting
commands.

The Cable Monitor is a read-only tool—it cannot be used to modify or reconfigure the Cisco uBR924
router. However, some of the information displayed in the advanced mode could be used to defeat the
router’s security. This information is available only to users who enter the enable password. Cisco
recommends that an encrypted enable password be set on all Cisco uBR924 routers deployed at
subscriber sites. Passwords (along with SNMP community strings) should be different for each router,
using a non-trivial pattern. If an enable password is not being used at a subscriber’s site, the Cable
Monitor should be run only in the basic mode.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

B-1

Appendix B

Using the Cable Monitor Tool

Enabling the Cable Monitor

The following sections describe the Cisco uBR924 router’s Cable Monitor:
•

Enabling the Cable Monitor

•

Disabling the Cable Monitor

•

Accessing the Cable Monitor

•

Sample Pages

Enabling the Cable Monitor
By default, the Cable Monitor is disabled. To allow technicians and subscribers to access the Cable
Monitor, it must be enabled using the ip http global configuration command as follows:
Command

Purpose

Step 1

ubr924(config)# ip http cable-monitor {basic | advance} Immediately enable the Cable Monitor in either basic
[URL-IP-address URL-mask]
or advanced mode. Optionally specify the IP address
and subnet mask for the Cable Monitor; these
parameters also define the IP address pool used by the
temporary DHCP server when the cable interface goes
down.

Step 2

ubr924(config)# ip http port http-port

Tip

(Optional) Specify the TCP port number to use for web
server (HTTP) requests. The default is the well-known
web server port of 80.

If the router is operating in routing mode, and the cable interface is up, you can also access the Cable
Monitor by entering the IP address for the Ethernet interface into your web browser.
When the Cable Monitor is enabled, it also automatically enables the Cisco web server (giving the
equivalent of the ip http server command). However, while the Cable Monitor is active, it disables all
other access to the Cisco web server, preventing the user from accessing the CLI commands that are
normally available when the Cisco web server is active. When the Cable Monitor is active, the Cisco web
server can be used only for displaying the Cable Monitor pages.

Note

If the Cable Monitor is not enabled on the Cisco uBR924 router, Cisco recommends that the Cisco web
server be disabled, using the no ip http server configuration command.

Configuration Modes
The ip http cable-monitor basic command enables the Cable Monitor and puts it in basic mode. In this
mode, the Cable Monitor displays information only about the router’s current status, whether it has
successfully completed all of its initialization routines, and cable performance statistics.
The ip http cable-monitor advance command enables the Cable Monitor and puts it in advanced mode.
In this mode, the Cable Monitor displays the router’s current status, the status of its initialization
routines, the status of the voice ports, the router’s basic configuration, and performance statistics. If an

Cisco uBR924 Software Configuration Guide

B-2

OL-0337-05 (8/2002)

Appendix B

Using the Cable Monitor Tool
Disabling the Cable Monitor

enable password is set, users who can supply the enable password can also view detailed debugging and
troubleshooting configuration information; if an enable password is not set, all users can view this
information.

Caution

To ensure a secure system, the advanced mode should not be used unless a secure encrypted enabled
password is configured on the Cisco uBR924 router.
By default, the Cable Monitor is configured with the IP address 192.168.100.1, which is a Class C
address in the private IP address space reserved for private networks. If a device on the subscriber’s
private network is already using this IP address, use the URL-IP-address and URL-mask optional
parameters to specify another IP address.
For example, to enable the Cable Monitor for advanced mode with the private IP address of 10.0.1.2 and
the default HTTP port of 80, use the following command:
ip http cable-monitor advance 10.0.1.2 255.0.0.0

Note

This command can be included in the Cisco IOS configuration file that is downloaded to the router at
power-on during the DOCSIS provisioning.

Security Considerations
The Cable Monitor is a read-only tool that cannot be used to change the configuration of the
Cisco uBR924 router. The debug page in advanced mode, however, does display information that could
be used to defeat the router's security. This page is password-protected, requiring users to enter the
enable password before displaying it; however, if an enable password has not been set, any user can
display the debug page, which could reveal SNMP community strings and other configuration
information.
For this reason, the following guidelines should be used when developing a security policy for the router:

Note

•

If the Cable Monitor is being used in advanced mode, an encrypted enable password must be set.
Otherwise, all users can view the debug page, which displays the router's complete configuration,
including SNMP community strings.

•

If no enable password is set, so as to prevent remote configuration of the router via Telnet, then the
Cable Monitor must be used only in basic mode.

Since downloading a Cisco IOS configuration file during the provisioning process automatically disables
the console port, all remote configuration of the Cisco uBR924 router using the CLI is disabled when an
enable password is not set. In this situation, the only way to change the router's configuration is through
SNMP or by resetting the router and uploading a new configuration file. The Cable Monitor, however,
must not be run in advanced mode when no enable password has been set because this would allow
unauthorized users to view SNMP community strings and use SNMP to change the router’s
configuration.

Disabling the Cable Monitor
To disable the Cable Monitor, use the ip http global configuration command as follows:

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

B-3

Appendix B

Using the Cable Monitor Tool

Accessing the Cable Monitor

Step 1

Command

Purpose

ubr924(config)# no ip http cable-monitor

Immediately disable the Cable Monitor, preventing
any web server access to its web pages. This also
automatically disables access to the Cisco web
server (which is equivalent to giving the no ip http
server command).

Note

The Cable Monitor is disabled by default, so the no ip http cable-monitor command does not need to
be included in the Cisco IOS configuration file that is downloaded to the router at power-on during the
DOCSIS provisioning. However, the Cisco web server is enabled by default; if this is not desirable, you
should include the no ip http server command in the Cisco IOS configuration file that is downloaded to
the Cisco uBR924 router.
When disabling the Cable Monitor, the console might display warning messages similar to the following:
%
%
%
%

monitor-209.165.202.131 is not in the database.
monitor-192.168.100.1 is not in the database.
Range [209.165.202.131, 209.165.202.131] is not in the database.
Range [192.168.100.1, 192.168.100.1] is not in the database.

These messages can be ignored because they are simply confirming that the IP addresses used for the
Cable Monitor are no longer being used for that purpose.

Note

The Cable Monitor can also be disabled by giving the no ip http server command, which disables all
web server access. However, this is not recommended because it does not release the system resources
that are specifically allocated to the Cable Monitor.

Accessing the Cable Monitor
The Cable Monitor can be accessed either through the cable interface (typically by technicians at the
headend or the service provider’s network operations center) or through the Ethernet interface (typically
by subscribers when the cable interface has gone down). See the following sections for more
information.
Note

You must be using a web browser that supports frames to access the Cable Monitor pages.

Through the Cable Interface when the Cable Interface is Operational
During normal operations—when the Cisco uBR924 router is online and has connectivity with the
CMTS through the cable interface—service technicians at the headend can access the Cable Monitor by
doing the following:
Step 1

Start a web browser on a PC or workstation at the headend that has TCP/IP connectivity with the
Cisco uBR924 router.

Cisco uBR924 Software Configuration Guide

B-4

OL-0337-05 (8/2002)

Appendix B

Using the Cable Monitor Tool
Accessing the Cable Monitor

Step 2

Type in a URL with the IP address assigned to the cable interface on the Cisco uBR924 router. This is
typically an address in the service provider’s IP address space.

For example, if the Cisco uBR924 router has been assigned the IP address of 209.165.202.131 by the
service provider, a technician at the headend would use the following URL to access the Cable Monitor:
http://209.165.202.131
If a port number other than the default of 80 has been assigned to the Cable Monitor, that port number
must be included as part of the URL. For example, if the Cisco uBR924 router has been assigned the IP
address of 209.165.202.131 and a port number of 8080 by the service provider, a technician at the
headend would use the following URL to access the Cable Monitor:
http://209.165.202.131:8080

Tip

If the router is operating in routing mode, and the cable interface is up, you can also access the Cable
Monitor by entering the IP address for the Ethernet interface into your web browser.

Through the Ethernet Interface when the Cable Interface is Not Operational
When the Cisco uBR924 router loses connectivity with the CMTS at the headend and detects that its
cable interface is not operational, the router automatically switches into a diagnostic mode and does the
following:
•

Activates a temporary DHCP server to assign IP addresses in the IP network that is defined by the
IP address and subnet mask given with the ip http cable-monitor command (the default address
pool is the Class C private network 192.168.100.0).

•

When a PC or other workstation connected to the router’s Ethernet ports makes a DHCP request, the
router assigns an IP address and default gateway from this address space so that the PC can
communicate with the Cable Monitor on the router.

Note

The PC or workstation can be rebooted to force it to make a DHCP request. If using a
Windows 95 or Windows 98 system, you can also use the winipcfg utility to send a DHCP
release and renew request.

•

When the router detects any web server requests, it automatically redirects them to the Cable
Monitor.

•

The router’s DHCP server renews these IP addresses every 30 seconds as long as the cable interface
is down.

•

When the cable interface is back up, the router returns to normal operation, using the configuration
that existed before it switched into diagnostics mode. (At this point, the PC or workstation that
accessed the Cable Monitor can be rebooted to restore its configuration, or you can wait from 30 to
60 seconds for the PC to automatically issue a DHCP renew request. Windows 95 or Windows 98
users can also use the winipcfg utility.)

When the cable interface is down, users at the subscriber site can use the following procedure to access
the Cable Monitor to aid in troubleshooting the problem with the cable network:
Step 1

If necessary, connect a PC to one of the Ethernet ports on the Cisco uBR924 router.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

B-5

Appendix B

Using the Cable Monitor Tool

Sample Pages

Step 2

If necessary, configure the PC so it obtains its IP address from a DHCP server—on Windows 95
computers, display the Network Control Panel, click the TCP/IP component for the computer’s Ethernet
adapter, click the IP Address tab under Properties, and click Obtain an IP address automatically.

Note

Since most PCs are configured to use a DHCP server, this step is not usually necessary. However, if the
PC is normally assigned a static IP address, you should copy down its IP address and default gateway
address before reconfiguring it to use a DHCP server.

Step 3

Reboot the PC so that it obtains an IP address from the Cisco uBR924 router.

Step 4

Start a web browser on the PC and enter any arbitrary URL, such as http://anything. The
Cisco uBR924 router redirects the request to the Cable Monitor, which displays its home page.

Note

Step 5

In the default configuration, the static IP address 192.168.100.1 is reserved for the Cable Monitor while
in diagnostic mode. If desired, subscribers (or technicians who visit the subscriber’s site) can enter the
URL http://192.168.100.1 as a bookmark for the Cable Monitor. If a different IP address has been
assigned to the Cable Monitor, users should enter that value as the bookmarked address.
When the cable interface resumes normal operations, reconfigure the PC (if necessary) to restore its
previous TCP/IP configuration. Then wait from 30 to 60 seconds or reboot the PC to restore normal
operations.

Sample Pages
Table B-1 lists each of the web pages displayed by the Cable Monitor, the modes in which the pages are
displayed, and a short description of each page’s information.
Table B-1

Cable Monitor Pages

Cable Monitor Page

Modes Available

Description

Home Page

Basic and Advanced

Displays current status and
initialization information.

Initialization Information

Advanced Only

Displays more detailed initialization
information.

Voice Ports Information

Advanced Only

Displays status and configuration
information for the router’s voice ports.

CPE State Information

Advanced Only

Displays the basic configuration for the
router.

Cable Interface Information

Advanced Only

Displays the current status and
configuration of the cable interface.

Performance Information

Basic and Advanced

Displays performance statistics for the
router.

Debug Information Page

Advanced Only
(requires enable
password)

Displays advanced configuration
information.

Cisco uBR924 Software Configuration Guide

B-6

OL-0337-05 (8/2002)

Appendix B

Using the Cable Monitor Tool
Sample Pages

The following sections describe each page in more detail.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

B-7

Appendix B

Using the Cable Monitor Tool

Sample Pages

Home Page
The Cable Monitor home page displays the current status of the LEDs on the front panel of the
Cisco uBR924 router and summarizes the status of the router’s registration process with the CMTS.
Figure B-1 shows a typical home page when the Cable Monitor is configured for advanced mode.
Figure B-1

Note

Cable Monitor Home Page

Figure B-1 shows the home page when the Cable Monitor is configured for advanced mode; in this mode,
the left side displays links for all available pages. When the Cable Monitor is configured for basic mode,
the left side displays only the link for the Performance Information page.
The top of the Cable Monitor home page displays the current status of the LEDs on the front panel of
the Cisco uBR924 router:
•

Link—If green, indicates that the cable interface is operational. If black, indicates that the cable
interface is not receiving a signal, typically because of a break in the cable connection.

•

Voice Port 1—If green, indicates that a call is active on voice port 1. If black, indicates that voice
port 1 is not in use.

Cisco uBR924 Software Configuration Guide

B-8

OL-0337-05 (8/2002)

Appendix B

Using the Cable Monitor Tool
Sample Pages

•

Voice Port 2—If green, indicates that a call is active on voice port 2. If black, indicates that voice
port 2 is not in use.

•

US—If green, indicates that the router has established connectivity with the CMTS and is operating
within 6 dB of the desired upstream power level. If black, indicates that the upstream power level is
not within the desired power level.

•

DS—If green, indicates that the router is locked and communicating on a downstream channel.

•

DSNR—If green, indicates that the router is receiving a quality downstream signal (this is a signal
that has a signal-to-noise ratio (SNR) that is 5 dB or more above the downstream lock threshold). If
black, indicates that noise on the downstream has exceeded the minimum recommended threshold,
and the signal is currently within 5 dB of failing due to excessive noise.

The Quick Status section of the home page summarizes the information that is displayed on the
Initialization Information page, described in the next section.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

B-9

Appendix B

Using the Cable Monitor Tool

Sample Pages

Initialization Information
The Initialization Information page is available to advanced users only and displays the same
information shown in the Quick Status section of the Home Page. This information summarizes the
router’s power-on initialization and registration process using the following color codes:
•

Stages that passed are shown in green.

•

Any stage that failed is shown in red.

•

Stages that were not reached because of the failure of a previous stage are shown in black.

Figure B-2 shows a display for a Cisco uBR924 router that has successfully registered and come online.
Figure B-2

Initialization Information Page

This page provides detailed information on the state changes when the Cisco uBR924 router tries to
establish communication and registration with the CMTS. All stages must show “Passed” before the
router can come online.
Clicking on the name of the stage displays more information, if available, in the bottom half of the
window. For example, clicking stage 11, “Download Configuration File state,” displays the name of the
configuration file that was downloaded to the router and the configuration parameters it contained.
The following is the normal progression of states that would be displayed if the Cisco uBR924 router
registers successfully with the CMTS:

Cisco uBR924 Software Configuration Guide

B-10

OL-0337-05 (8/2002)

Appendix B

Using the Cable Monitor Tool
Sample Pages

•

Reset state—The router boots the Read-Only Memory (ROM) from its Flash memory, performs a
self-test, initializes processor hardware, and boots the Cisco IOS release image stored in Flash
memory.

•

Wait for link up state—The router checks the cable interface and determines whether a
DOCSIS-compliant signal exists.

•

Downstream frequency scanning state—The router acquires a temporary downstream channel by
matching the clock sync signal that is regularly sent out by the CMTS in the downstream frequency
range. If this stage passes, click this link to display the following information:
– Downstream ID
– Downstream Frequency
– Downstream Symbol Rate
– Downstream QAM Mode
– Signal to Noise Ratio Estimate
– Downstream Lock Threshold
– Downstream Search

•

Wait for Upstream Channel Descriptor (UCD) state—The router waits for an Upstream Channel
Descriptor (UCD) message from the CMTS and configures itself for the upstream frequency
specified in that message. If this stage passes, click this link to display the following information:
– Upstream ID
– Upstream Frequency
– Mini-Slot Size

•

Wait for MAP state—The router waits for the next upstream bandwidth allocation map message
(MAP), which are regularly sent from the CMTS, to find the next available shared request timeslot.

•

Power ranging first state—The router then uses the MAP timeslot to send a ranging request message
to the CMTS, communicating the router's user ID (UID, which is its unique MAC address), using a
temporary Service Identifier (SID) of 0 (zero) to indicate it has not yet been allocated an upstream
channel. If this stage passes, click this link to display the following information:
– Ranging Offset
– Power Level
– Ranging Response SID Assigned
– Adjust Transmit Power

•

Power ranging second state—In reply to the router's ranging request, the CMTS sends a ranging
response containing a temporary SID to be used for the initial router configuration and bandwidth
allocation. As needed, the router adjusts its transmit power levels using the power increment value
given by the CMTS in its ranging response message.

•

DHCP state—After the next MAP message broadcast, the router uses a shared require timeslot to
invoke the Dynamic Host Configuration Protocol (DHCP) to establish IP connectivity with the
TCP/IP network at the headend. The DHCP server sends a response with the following information:
– Assigned IP Address
– Network Mask
– TFTP Server IP Address
– Time Server IP Address

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

B-11

Appendix B

Using the Cable Monitor Tool

Sample Pages

– Time Zone Offset
– Configuration File Name
•

Time of Day (TOD) state—The router configures itself for the specified IP address and gets the
current date and time from the specified ToD server.

•

Security association state—Reserved for future use.

•

Download configuration file state—Using the TFTP protocol, the router downloads the specified
DOCSIS configuration file and configures itself for the appropriate parameters. The DOCSIS
configuration file contains the following parameters:
– Configuration File
– Network Access
– Maximum CPEs
– Class of Service information—Depending on the software image installed, up to four classes of

service (CoS) are displayed. The following information is shown for each CoS:
Assigned SID
Max Downstream Rate
Max Upstream Rate
Upstream Priority
Min Upstream Rate
Max Upstream Burst
Privacy Enable

Note

For more information on these parameters, see the “DOCSIS Configuration File” section on
page 2-3.

•

Registration state— The router sends another registration request to the CMTS containing the CoS
parameters given in the DOCSIS configuration file. The CMTS verifies that the router is using the
appropriate CoS profile and converts the temporary SID into a data SID with a service class index
that points to the applicable CoS profile.

•

Establish baseline privacy state—If BPI security has been enabled, the router negotiates the BPI
parameters with the CMTS.

•

Maintenance state—The router enters the maintenance state, passing traffic on the cable interface to
and from the CMTS, and responding to periodic maintenance messages from the CMTS.

Cisco uBR924 Software Configuration Guide

B-12

OL-0337-05 (8/2002)

Appendix B

Using the Cable Monitor Tool
Sample Pages

Voice Ports Information
The Voice Ports Information page summarizes the current status of the two voice ports on the
Cisco uBR924 router. Figure B-3 shows a typical Voice Ports Information page.
Figure B-3

Note

Voice Ports Page

The Voice Ports Information page has valid information only when the Cisco uBR924 router is running
a software image with voice support.
The Voice Ports Information page displays the same information that is shown using the show voice port
command:
•

Transport Used—The type of network being used to make calls on each voice port:
– VoIP—The voice call is using Voice over IP transmitted over the cable interface (default).
– Analog—The voice call is using the PTSN cutover port, indicating that the cable interface is

down or that power was temporarily interrupted to the router.
•

Type—The type of voice port (always “FXS” for the Cisco uBR924 router).

•

Operation State—The current functional status of the voice port:

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

B-13

Appendix B

Using the Cable Monitor Tool

Sample Pages

– UP—The port is online and currently making a call.
– DOWN—The port is online but is not currently making a call.
– TESTING—The port is in the middle of a test procedure, either its power-on self-test or a test

manually initiated by a technician.
– UNKNOWN—The port is an unknown state. This might indicate you are using an out of date

software image.
– DORMANT—The port is not currently in use.
– NOT PRESENT—The port is not present. Either the voice port hardware has failed or a software

image with voice support has been loaded on a Cisco cable access router that does not support
voice ports.
•

Administrative State—The configuration of the voice port:
– UP—The port is enabled and ready to accept and make calls.
– DOWN—The port is disabled and cannot accept or make calls.
– TESTING—The port has been put into test mode, typically by a technician who is manually

testing the port.
•

Interface Down Failure—Whether the voice port is currently experiencing an interface down failure.

•

Noise Regeneration—Whether background noise should be played to fill silent gaps.

•

Non Linear Processing—Whether non-linear echo cancellation is enabled for this port.

•

Music on Hold Threshold—The current music-on-hold threshold (-7 0dB to -30 dB) for the port.

•

In Gain—The amount of input gain (-6 dB to 14 dB) inserted at the receiver side of the port.

•

Out Attenuation—The amount of output attenuation (0 dB to 14 dB) inserted at the transmit side of
the port.

•

Echo Cancellation—Whether echo cancellation is enabled for this port.

•

Echo Cancel Coverage—The amount of time to be covered with echo cancellation (8, 16, 24, or 32
milliseconds)

•

Connection Mode—The connection mode of the voice port.

•

Connection Number—The full E.164 telephone number used to establish a connection.

•

Initial Time Out—The maximum amount of time the port waits for an initial input digit after going
off-hook (0 to 120 seconds).

•

InterDigit Time Out—The maximum DTMF interdigit duration (0 to 120 seconds).

•

Call Disconnect Time Out—The maximum amount of time the port waits to disconnect a call after
the remote side hangs up (0 to 120 seconds).

•

Region Tone—The type of ringing tone (cptone) generated by the port, as defined by locale (2-letter
ISO-3166 country code).

Cisco uBR924 Software Configuration Guide

B-14

OL-0337-05 (8/2002)

Appendix B

Using the Cable Monitor Tool
Sample Pages

CPE State Information
This page summarizes how the Cisco uBR924 router has been configured at the MAC (physical) layer.
Figure B-4 shows a typical CPE State Information page.
Figure B-4

CPE State Information Page

The following information is shown in the CPE State Information page:
•

Router Name—Shows the hostname assigned to the router.

•

IP Address—Shows the IP address assigned to the router’s cable interface.

•

Net Mask—Shows the subnet mask for the cable interface.

•

MAC State—Indicates the current MAC layer state (during normal operation, this is
“maintenance_state”). The following are the possible MAC layer states; they correspond to the
states shown in the Initialization Information page:
– wait_for_link_up_state—Wait for Link Up state
– ds_channel_scanning_state—Downstream Channel Scanning state
– wait_ucd_state—Wait for UCD state
– wait_map_state—Wait for MAP state
– ranging_1_state—Ranging 1 state

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

B-15

Appendix B

Using the Cable Monitor Tool

Sample Pages

– ranging_2_state—Ranging 2 state
– dhcp_state—DHCP state
– establish_tod_state—Time of Day state
– security_association_state—Security Association state
– configuration_file_state—Download Configuration File state
– registration_state—Registration state
– establish_privacy_state—Establish Privacy state
– maintenance_state—Maintenance state
•

Ranging SID—The SID assigned to the router by the CMTS.

•

Registered—Indicates whether the router successfully registered with the CMTS.

•

Privacy Established—Indicates whether the router established a BPI security session with the
CMTS.

•

TFTP Server IP Address—Shows the IP address for the TFTP server that downloaded the DOCSIS
configuration file to the router.

•

Time Server IP Address—Shows the IP address for the ToD server that provided the correct
time-of-day to the router.

•

Time Zone Offset—Shows the time zone that the router has been configured to use.

•

Downstream Info—Click this link to display the following downstream characteristics:
– DS ID—The Downstream ID assigned to the router.
– DS Frequency—The frequency in MHz of the downstream assigned to the router.
– DS Symbol Rate—The symbol rate currently used on the downstream.
– DS QAM Mode—The bandwidth used on the downstream (64 QAM or 25 6QAM).
– Signal-to-Noise Ratio Estimate—The current SNR calculated for the downstream.
– DS Lock Threshold—The minimum SNR signal that the router requires to maintain a lock on

the downstream signal.
•

Upstream Info—Click this link to display the following upstream characteristics:
– US ID—The Upstream ID assigned to the router.
– US Frequency—The frequency in MHz of the upstream assigned to the router.
– US Power Level—The target power level that the router should be using on the upstream.
– US Symbol Rate—The symbol rate currently used on the upstream.
– Ranging Offset—The delay correction, in units of 6.25 microseconds, that the router must apply

to the CMTS Upstream Frame Time to synchronize upstream transmissions.
– Mini-Slot Size—The size of the DOCSIS mini-slots in units of 6.25 microseconds. Possible

values are 2, 4, 8, 16, 32, 64, or 128.
– Change Count—The DOCSIS configuration change count, which tracks how many times the

UCD parameters for a router have changed.
•

Configuration File Info—Click this link to display the contents of the DOCSIS configuration file
that the router downloaded during its power-on provisioning.

Cisco uBR924 Software Configuration Guide

B-16

OL-0337-05 (8/2002)

Appendix B

Using the Cable Monitor Tool
Sample Pages

Cable Interface Information
The Cable Interface Information page provides information on the Cisco uBR924 router’s cable interface
and the quality of its signal. When the cable interface is not operational, the information provided is
based on the live values last available.
Figure B-5 shows a typical Cable Interface page.
Figure B-5

Cable Interface Information Page

The following information is displayed on the Cable Interface page:
•

IP Address—The IP address assigned to the cable interface during DOCSIS provisioning.

•

Network Mask—The subnet mask assigned to the cable interface during DOCSIS provisioning.

•

MAC Address—The MAC (physical) layer address assigned to the router at the factory.

•

Signal Quality—The signal quality interprets the signal-to-noise ratio (SNR) as follows:
– Unreliable link (displayed in red)—SNR is 2,000 above the lock threshold; the link is likely to

fail or go offline intermittently.
– Poor link (displayed in yellow)—SNR is 4,000 above the lock threshold; the link may

occasionally go offline intermittently.
– Acceptable link (displayed in green)—SNR is 6,000 above the lock threshold; the link is good.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

B-17

Appendix B

Using the Cable Monitor Tool

Sample Pages

•

Signal to Noise Ratio Estimate—The current SNR value used to determine the Signal Quality.

•

Lock Threshold—The lock threshold value used to determine the Signal Quality.

•

Power Level—The current upstream power level that the router is using.

The following are errors encountered by the router at the MAC layer:
•

Mac Resets—The number of times that the router has reset its MAC layer.

•

Sync Lost—The number of times that the router has lost sync on the cable interface and the link has
gone down.

•

Invalid Maps—The number of invalid MAPs that the router has received from the CMTS.

•

Invalid UCDs—The number of invalid UCDs that the router has received from the CMTS.

•

Invalid Ranging Response—The number of invalid ranging responses that the router has received
from the CMTS.

•

Invalid Registration Response—The number of invalid registration responses that the router has
received from the CMTS. Typically, an invalid registration response is due to either an
authentication failure or a class of service failure.

•

T1 Timeouts—The number of times that the router timed out waiting for a UCD message from the
CMTS.

•

T2 Timeouts—The number of times that the router timed out waiting for a broadcast ranging
response from the CMTS.

•

T3 Timeouts—The number of times that the router timed out waiting for a ranging response from
the CMTS.

•

T4 Timeouts—The number of times the router has reinitialized its MAC layer because it did not
receive a Periodic Ranging opportunity from the CMTS.

•

Range Aborts—The number of times that the CMTS has instructed the router to abort a ranging
attempt, typically because of excessive ranging or excessive power levels.

Cisco uBR924 Software Configuration Guide

B-18

OL-0337-05 (8/2002)

Appendix B

Using the Cable Monitor Tool
Sample Pages

Performance Information
This page is available to all users and provides basic performance statistics for the Cisco uBR924 router.
Figure B-6 shows a typical Performance Information page.
Figure B-6

Performance Information Page

The following information is displayed on the Performance Information page:
•

System Uptime—The total time since the router was last reset or powered on.

•

CPU Utilization for 5 seconds—The average CPU load (0 to 100%) for the past 5 seconds.

•

CPU Utilization for 1 minute—The average CPU load (0 to 100%) for the past 1 minute.

•

CPU Utilization for 5 minutes—The average CPU load (0 to 100%) for the past 5 minutes.

•

Output Packets—The total number of MAC layer packets output on the upstream at the cable
interface.

•

Output Bytes—The total number of bytes output on the upstream at the cable interface.

•

Output Queue—The current state of the output queue, shown as a ratio of the number of packets
currently in the queue over the maximum size of the queue.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

B-19

Appendix B

Using the Cable Monitor Tool

Sample Pages

•

5 minute Output Rate—The average output rate over the past five minutes, in both bits per second
and packets per second. For example, “10/40” shows that 10 packets are currently in the queue,
which can hold 40 packets.

•

Input Packets—The total number of MAC layer packets received on the downstream at the cable
interface.

•

Input Bytes—The total number of bytes output on the downstream at the cable interface.

•

Input Queue—The current state of the input queue, shown as a ratio of the number of packets
currently in the queue over the maximum size of the queue. For example, “13/75” shows that 13
packets are currently in the queue, which can hold 75 packets.

•

5 minute Input Rate—The average input rate over the past five minutes, in both bits per second and
packets per second.

•

Transmit Load—The current transmit load, shown as a ratio of the packets currently in the transmit
buffer over the size of the buffer.

•

Receive Load—The current receive load, shown as a ratio of the packets currently in the receive
buffer over the size of the buffer.

Cisco uBR924 Software Configuration Guide

B-20

OL-0337-05 (8/2002)

Appendix B

Using the Cable Monitor Tool
Sample Pages

Debug Information Page
This page displays the output of the show tech-support command, which includes the output of the
following CLI commands:
•

show version—Displays the hardware configuration, software image names and version, register
settings, and the boot image.

•

show running-config—Displays the configuration the router is currently using.

•

show stacks—Displays the stack usage of the router’s processes and interrupt routines, including
the reason for the last system reboot.

•

show interfaces—Displays the status and configuration of the router’s Ethernet and cable
interfaces.

•

show controllers—Displays the current state, configuration, and register information for each
controller that the Cisco uBR924 router uses to move data between the cable and Ethernet interfaces.

•

show controller c0 mac state—Displays the MAC layer configuration for the cable interface.

•

show voice port—Displays the configuration of each voice port.

•

show dial-peer voice—Displays the remote and local dial-peers that have been configured on the
router.

•

show gateway—Displays the gateway configuration (if any).

•

show call active voice—Displays the contents of the active call table, which shows statistics for the
voice calls currently in progress.

•

show call history voice—Displays the call history table, which lists all voice calls connected
through the router’s voice ports.

•

show region—Displays information about the memory regions in the router.

•

show process memory—Displays details about how tasks are using the router’s memory.

•

show process cpu—Displays details about how tasks are using the router’s CPU.

•

show buffers—Displays the usage of the different memory buffers on the router.

If an enable password has been set, the user must enter the level 15 user ID and password to access this
page. If no enable password has been set, this page is accessible to all users.

Note

Cisco recommends that an encrypted enable password be set on all Cisco uBR924 routers that are
deployed at subscriber sites. If an encrypted enable password is not being used at a subscriber’s site, the
Cable Monitor should not be enabled in advanced mode because the Debug Information page displays
information, such as the SNMP community strings, that could be used to defeat the router’s security.
Figure B-7 shows a typical Debug Information page.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

B-21

Appendix B

Using the Cable Monitor Tool

Sample Pages

Figure B-7

Debug Information Page

Cisco uBR924 Software Configuration Guide

B-22

OL-0337-05 (8/2002)

A P P E N D I X

Using the ROM Monitor
This appendix describes the Cisco uBR924 cable access router ROM monitor, which helps you isolate
and troubleshoot possible hardware problems when installing the router. The ROM monitor is the first
software to run when the Cisco uBR924 router is powered-on or reset; it is permanently part of the
Cisco uBR924 router and is always available, regardless of the release of Cisco IOS software that has
been downloaded to the router.
This appendix describes:

Caution

•

Entering the ROM Monitor, page C-1

•

Command Conventions, page C-2

•

Commands, page C-2

Users and system administrators do not need to access the ROM monitor during normal operation of the
Cisco uBR924 router. The ROM monitor should be used only by trained service technicians or under the
direction of a Cisco TAC engineer. Many of the commands available in the ROM monitor put the router
in a diagnostic or non-functional state—do not enter any commands in the ROM monitor unless you
thoroughly understand their function and how to reverse their effects so you can restore the router to
normal operations.

Entering the ROM Monitor
The ROM monitor initializes the processor hardware and boots the main operating system software. The
ROM monitor version introduced in the Cisco IOS Release 12.0(4)XI timeframe displays as follows:
rommon 2 > i
System Bootstrap, Version 12.0(19990506:181223)[sjacobso-jac-xi26 2504] DEVELOPMENT
SOFTWARE
Copyright (c) 1994-1999 Cisco Systems, Inc.
UBR924 platform with 16384 Kbytes of main memory

The ROM monitor main memory information is shown below:
rommon 3 > meminfo
Main memory size: 16 MB
Available main memory starts at 0x14000, size 16304 KB
I/O (packet) memory size: 512 KB
NVRAM size: 16 KB

To default to booting at the ROM monitor while running the system software, reset the configuration
register to 0x0 by entering the following Cisco IOS global configuration command:

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

C-1

Appendix C

Using the ROM Monitor

Command Conventions

Router(config)# config-reg 0x0
The new configuration register value, 0x0, takes effect after the router is rebooted with the reload
Privileged EXEC command. If you set the configuration to 0x0, you will have to manually boot the
system from the console each time you reload the router.

Note

After you have entered the ROM monitor, you can return to the normal boot mode by changing the
configuration register value to 0x2103, using the confreg 0x2102 ROMMON command. Then reboot the
system using the reset ROMMON command.

Command Conventions
Following are ROM monitor command conventions:
•

Brackets [ ] denote an optional field. If a minus option is followed by a colon (for example: [-s:]),
you must provide an argument for the option.

•

A word in italics means that you must fill in the appropriate information.

•

All address and size arguments to the memory-related commands are assumed to be hexadecimal
(no “0x” prefix or “h” suffix needed).

•

The options [-bwl] for the memory-related commands provide for byte, word, and longword
operations. The default is word.

•

You can invoke the memory-related commands by typing the command with no arguments. This
causes the utility to prompt you for parameters. This option is available for the commands marked
as prompting.

•

You can place more than one command (except the repeat command) on a line by using the “;”
delimiter.

Commands
Enter ? or help at the rommon > prompt to display a list of available commands and options:
rommon 12 > help
alias
boot
confreg
cont
context
cookie
dev
dir
dnld
frame
help
history
meminfo
repeat
reset
set
stack
sync

set and display aliases command
boot up an external process
configuration register utility
continue executing a downloaded image
display the context of a loaded image
display contents of cookie PROM in hex
list the device table
list files in file system
serial download a program module
print out a selected stack frame
monitor builtin command help
monitor command history
main memory information
repeat a monitor command
system reset
display the monitor variables
produce a stack trace
write monitor environment to NVRAM

Cisco uBR924 Software Configuration Guide

C-2

OL-0337-05 (8/2002)

Appendix C

Using the ROM Monitor
Commands

sysret
unalias
unset
xmodem

Note

print out info from last system return
unset an alias
unset a monitor variable
x/ymodem image download

You can display additional details for a command by entering the command name with a -? option, which
prints the command usage message.
The commands are listed and described in alphabetical order. Note that the ROM monitor commands are
case-sensitive.
•

alias [name=value]—Aliases a name to a value. The ROM monitor’s version of command aliasing
is based on the aliasing function built into the Korn shell. Aliasing allows you to abbreviate
commands or to set up a command so that it is automatically run with certain options.
If the value contains white space or other special characters, it must be quoted. If the value has a
space as the last character the next command line word is also checked for an alias (normally only
the first word on the command line is checked).
The alias command is used to set new aliases and to view the aliases that are currently defined. For
example, to display the currently set aliases, enter the alias command by itself:
rommon 1 > alias
r=repeat
h=history
?=help
b=boot
ls=dir

The following command creates the alias “bf” that performs the “boot from Flash memory”
command:
rommon 1 > alias bf “b flash:”

•

boot or b—Boots an image. The boot command with no arguments boots the first image in boot
Flash memory. You can include an argument, filename, to specify a file to be booted over the
network using the Trivial File Transfer Protocol (TFTP). The local device (see the description of
b device following) can be specified by entering the device specifier (devid). If the specified device
name is not recognized by the ROM monitor, the system will attempt to boot the image (imagename)
from a network TFTP server. Do not insert a space between devid and imagename. Options to the
boot command are -x, load image but do not execute, and -v, verbose. The form of the boot command
follows:
boot [-xv] [devid] [imagename]
b—Boots the default (first) system software.
b filename [host]—Boots using a network TFTP server. When a host is specified, either by name or
IP address, the boot command will boot from that source.
b flash:—Boots the first file in Flash memory.
b device:—Boots the first file found in the Flash memory device. The Flash memory device
specified can be either flash:, to boot the Cisco IOS software, or bootflash:, to boot the boot image
in Flash memory.
b device:name—An extension of the above command, allows you to specify a particular filename in
the Flash memory.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

C-3

Appendix C

Using the ROM Monitor

Commands

•

confreg [hexnum]—Executing the confreg command with the argument hexnum changes the virtual
configuration register to match the hex number specified. Without the argument, confreg dumps the
contents of the virtual configuration register in English and allows the user to alter the contents. You
are prompted to change or keep the information held in each bit of the virtual configuration register.
In either case, the new virtual configuration register value is written into non-volatile memory
(NVRAM, also known as Flash memory) and does not take effect until you reset or power cycle the
router.
The configuration register resides in Flash memory. The configuration register is identical in
operation to other Cisco access servers. Enter confreg for the menu-driven system, or enter the new
value of the register in hexadecimal.

Note

The value is always interpreted as hexadecimal. The confreg utility will print a before and after view of
the configuration register when used in menu-driven mode.
For example:
rommon 7 > confreg
Configuration Summary
enabled are:
console baud: 9600
boot: the ROM Monitor
do you wish to change the configuration? y/n [n]:
enable “diagnostic mode”? y/n [n]: y
enable “use net in IP bcast address”? y/n [n]:
enable “use all zero broadcast”? y/n [n]:
enable “ignore system config info”? y/n [n]:
change console baud rate? y/n [n]: y
enter rate: 0 = 9600, 1 = 4800, 2 = 1200, 3 = 2400
change the boot characteristics? y/n [n]: y
enter to boot:
0 = ROM Monitor
1 = the boot helper image
2-15 = boot system
[0]: 0

[0]:

Configuration Summary
enabled are:
diagnostic mode
console baud: 9600
boot: the ROM Monitor
do you wish to change the configuration? y/n

[n]:

You must reset or power cycle for new config to take effect.

•

cont [-b]—Continues a loaded image that has stopped. For example:
reboot> launch
monitor: command “launch” aborted due to user interrupt
diagmon 7 > cont
reboot >

•

context—Displays the CPU context at the time of the fault. The context from the kernel mode and
process mode of a booted image is displayed, if available. For example:
rommon 6 > context
CPU Context:

Cisco uBR924 Software Configuration Guide

C-4

OL-0337-05 (8/2002)

Appendix C

Using the ROM Monitor
Commands

d0
d1
d2
d3
d4
d5
d6
d7
pc

•

0x00000028
0x00000007
0x00000007
0x00000000
0x00000000
0x02003e8a
0x00000000
0x00000001
0x02004adc

a0
a1
a2
a3
a4
a5
a6
a7
vbr

0x0ff00420
0x0ff00000
0x02004088
0x020039e6
0x02002a70
0x02003f17
0x02003938
0x0200392c
0x02000000

cookie—Displays the contents of the cookie PROM in hexadecimal format. For example:
rommon 1 > cookie
cookie:
01 01 00 00 0c 07 af 80 07 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

•

dev—Lists boot device identifications on the router. For example:
rommon 10 > dev
Devices in device table:
id name
eprom: eprom
flash: PCMCIA slot 1

•

dir devid—Lists the files on the named device. For example:
rommon 11 > dir flash:
File size
65 bytes (0x41)
2229799 bytes (0x220627)

Checksum
0xb49d
0x469e

File name
clev/oddfiles65
C5200-k.z

•

dlnd [-xv:] [args]—Downloads in binary format through the console and executes. The -x option
downloads, but does not execute. The -v option allows you to specify the verbose level. The optional
arguments are passed to the downloaded program via the argc/argv mechanism (only when -x is not
used). The exit value is the return value from the downloaded routine or the status of the download
operation (success or failure) if the -x option is used.

•

frame [number]—Displays an entire individual stack frame. Enter a number to indicate which
frame to display. You can also specify a number to indicate which stack frame to display. Note that
the default is 0 (zero), which is the youngest frame. For example:
rommon 6 > frame 2
Frame 02: FP = 0x02003960
at 0x02003968 (fp + 0x08)
at 0x0200396c (fp + 0x0c)
at 0x02003970 (fp + 0x10)
at 0x02003974 (fp + 0x14)
at 0x02003978 (fp + 0x18)
at 0x0200397c (fp + 0x1c)
at 0x02003980 (fp + 0x20)
at 0x02003984 (fp + 0x24)
at 0x02003988 (fp + 0x28)
at 0x0200398c (fp + 0x2c)

=
=
=
=
=
=
=
=
=
=

RA = 0x020050ee
0x02004f8d
0x0200f390
0x02006afc
0xc0a82983
0x02003a7e
0x02002630
0x00000000
0x02000000
0x0200c4a4
0x0200f448

•

history or h—Displays the command history, that is, the last 16 commands executed in the monitor
environment.

•

meminfo—Displays the size (in bytes) the starting address, the available range of the main memory,
the starting point and size of packet memory, and the size of non-volatile Flash memory. For
example:
rommon 9 > meminfo

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

C-5

Appendix C

Using the ROM Monitor

Commands

Main memory size: 8 MB. Packet memory size: 4 MB
Available main memory starts at 0xa000e001, size 0x7f1fff
Packet memory starts at 0xa8000000
NVRAM size: 0x20000

•

repeat [number or string] [count] or r—Repeats the specified command. Without an argument,
repeats the last command. The optional command number (from the history list) or match string
specifies which command to repeat. In the case of the match string, the most recent command to
begin with the specified string will be re-executed. If the string includes spaces, you must define it
using quotes. The count option allows you to repeat the command more than once.

•

reset or i—Resets and initializes the system, similar to power-on.

•

set—Displays all the monitor variables and their values.

•

stack [num]—Produces a stack trace of the num frames. The default is 5. The command dumps from
the kernel stack and the process stack (if one is available) of a booted image. For example:
rommon 5 > stack 8
Stack trace:
PC = 0x02004adc
Frame 00: FP = 0x02003938
Frame 01: FP = 0x02003948
Frame 02: FP = 0x02003960
Frame 03: FP = 0x02003994
Frame 04: FP = 0x02003b00

RA
RA
RA
RA
RA

=
=
=
=
=

0x02005f2a
0x02005df0
0x020050ee
0x02004034
0x00012ca6

•

sync—Writes the working in-core copy of the environment variables and aliases to Flash memory
so that they are read on the next reset.

•

sysret—Displays the return information from the last booted system image. This includes the reason
for terminating the image, a stack dump of up to eight frames, and if an exception is involved, the
address where the exception occurred. For example:
rommon 8 > sysret
System Return Info:
count: 19, reason: reset
pc:0x60043754, error address: 0x0
Stack Trace:
FP: 0x80007e78, PC: 0x60043754
FP: 0x80007ed8, PC: 0x6001540c
FP: 0x80007ef8, PC: 0x600087f0
FP: 0x80007f18, PC: 0x80008734

•

unalias name—Removes name and its associated value from the alias list.

Cisco uBR924 Software Configuration Guide

C-6

OL-0337-05 (8/2002)

A P P E N D I X

New and Changed Commands Reference
All cable-specific commands for the Cisco uBR924 cable access router in Cisco IOS Release 12.2(8)
and later releases are described in the Cable CPE Commands chapter in the Cisco Broadband Cable
Command Reference Guide, available on Cisco.com and the Customer Documentation CD-ROM. This
chapter is regularly updated to include all command changes and additions.

Note

To locate the documentation for the “related commands” mentioned in this chapter, use the Cisco IOS
Release 12.2 command reference master index that is available on Cisco.com and the Documentation
CD-ROM.

Commands Reserved for DOCSIS Use
In Cisco IOS Release 12.1(2)T and later releases, the following commands were removed from the CLI:
•

[no] cable-modem downstream saved channel

•

[no] cable-modem fast-search

•

[no] cable-modem downstream symbol rate

•

[no] cable-modem transmit-power

•

[no] cable-modem upstream preamble qpsk

In Cisco IOS Release 12.1(2)T and later software releases, these commands are now reserved exclusively
for DOCSIS use. These commands can appear in the router’s Cisco IOS configuration file, but they
cannot be given through the router’s CLI.

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

D-1

Appendix D

New and Changed Commands Reference

Commands Reserved for DOCSIS Use

Cisco uBR924 Software Configuration Guide

D-2

OL-0337-05 (8/2002)

I N D EX

Cable Monitor

Symbols

accessing
# character

B-4

cable interface

privileged EXEC prompt

A-5

debug

user EXEC mode

B-17

CPE state information

> prompt
? command

1-5, B-1 to B-22

A-4

A-6

B-15

B-21

disabling

B-3

enabling

B-2

home page

B-8

initialization information

Numerics

modes of operation

3DES encryption

performance

1-9, 1-13

B-2

B-19

security considerations
voice ports

B-3

B-13

Caution
delays in VoIP networks

abbreviating commands
context-sensitive help
alias command

B-10

4-4

voice operations regulation

A-6

Cisco Cable Clock Card

C-3

4-4

1-5

classes of service
see CoS

classes of service, multiple

Baseline Privacy Interface (BPI)
boot command

codecs

1-6

supported by VoIP

C-3

4-4

command

booting
from the ROM monitor
Bridging, DOCSIS

1-15

C-3

1-2

alias

C-3

boot

C-3

cable-modem downstream saved channel
cable-modem downstream symbol rate

cable-modem fast-search

cable-modem downstream saved channel command
cable-modem downstream symbol rate command
cable-modem fast-search command

D-1
D-1

cable-modem transmit-power command

cable-modem transmit-power

D-1

cable-modem upstream preamble qpsk
confreg

D-1

cable-modem upstream preamble qpsk command

D-1

cont

D-1

commands reserved for DOCSIS use

D-1

D-1
D-1

C-4

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

IN-1

Index

context

cookie command

C-4

CoS

C-5

dev (device)
dir

description in VoIP

C-5

CPE, maximum number

C-5

dlnd

C-5

meminfo

C-5

mgcp

4-18

DES encryption

repeat

C-6

dev (device) command

C-6
C-2
C-1

proxy support

C-6

server

4-15

stack

C-6

sync

C-6

sysret

2-3

1-7

1-6

diagnostics
ROM monitor
dir command

C-6

unalias

C-5

assigning a default gateway

ROM monitor diagnostics
sgcp

1-9

DHCP

ROM monitor
set

1-13

C-5

history

reset

1-3

crypto dynamic-map command

C-5

frame

C-5

dlnd command

C-6

commands reserved for DOCSIS use

commands, recalling

A-7

provisioning

A-7

Dynamic Crypto Map

global configuration

1-2

1-13

A-5

A-4

summary (table)

D-1

A-5

interface configuration
privileged EXEC

2-3

1-14

DOCSIS-compliant bridging feature set

command modes

user EXEC

C-5

assigning the default gateway by a DHCP server

A-8

description

C-5

DOCSIS

command history
buffer size

C-1

A-4

Easy IP feature set

A-4

1-3

Ecosystem Gatekeeper feature set

commands

1-7

EXEC

show ip default-gateway

2-3

commands

compression/decompression algorithms
supported by VoIP

privileged level

4-4

switching from privileged to user

configuration file
NAT/PAT

A-4

user level

A-5

A-4

3-8

configuration register
confreg command
cont command

C-4

context command

F
Firewall feature set

1-5

C-4

Cisco uBR924 Software Configuration Guide

IN-2

OL-0337-05 (8/2002)

Index

frame command

security considerations

C-5

voice ports

B-3

B-13

G
I

gateway
assigning a default gateway via DHCP

2-3

initial power-on
description

global configuration mode
accessing
exiting

installation

A-5

commands

connecting console cables

A-5

description

A-4

summary

A-5
A-4

Internet Locator Service (ILS) support

H
H.323

A-2

interface configuration mode

A-5

summary

1-14

IPsec

DTMF digit relay
Fast Connect

1-8

Hookflash relay

L2TP

1-8

support for virtual interfaces
H.323 support

h323-gateway voip bind srcaddr command
help
See context-sensitive help
A-6

history command

M
maximum number of CPE devices

1-3

Media Gateway Control Protocol

1-10

C-5

MGCP
1-3

C-5

1-10

mgcpapp command

4-18

B-1 to B-22

mgcp configuration

4-18

B-4

modes

cable interface

B-17

See command modes

CPE state information
debug

1-9

meminfo command

Home Office feature set
accessing

1-4, 1-9

1-9

4-2

help command

1-13

1-7

1-8

H.245 Tunneling

1-13

Dynamic Crypto Map

1-8

Ecosystem gatekeeper enhancements

HTTP Tool

1-4, 1-9

3DES

1-8

1-10

B-15

multiple classes of service

1-15

B-21

enabling

B-2

home page

B-8

initialization information
modes of operation
performance

B-19

B-2

B-10

NAT/PAT
sample configuration
NAT/PAT feature set

3-8
1-10

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

IN-3

Index

NetMeeting ILS support
NetMeeting ILS support
NetRanger feature set

1-10

repeat command

1-10

reset command

number character
privileges EXEC prompt

RIPv2

A-5

C-6
C-6

1-12

ROM monitor

commands

C-2

diagnostics

C-1

entering

operations
voice connections

C-1

4-1

Routing Information Protocol

1-12

P
S
PAT
sample configuration

Secure Shell

3-8

Performance Small and Branch Office feature set
Performance Telecommuter feature set
pots port command

1-4

A-4

description
prompt

A-4

connecting console cables

4-15

sgcp configuration

4-15

A-7, A-11
2-3

Simple Gateway Control Protocol

1-12

See SGCP
1-12

stack command

C-6

1-14

sync command

C-6

1-14

sysret command

A-4

description

4-2

show ip default-gateway command

SSH

provisioning

1-12

sgcpapp command

A-2

prompts

B-3

C-6

show history command

procedures

system

set command

SGCP support

A-4

summary

security considerations of the Cable Monitor
SGCP

1-8

privileged EXEC mode
accessing

1-5

1-12

C-6

Q
QoS

Tab key

1-11

multiple classes of service
Quality of Service

1-11

question command

A-6

1-15

command completion

A-6

Triple Data Encryption Standard

1-13

Cisco uBR924 Software Configuration Guide

IN-4

OL-0337-05 (8/2002)

Index

U
unalias command

C-6

user EXEC mode
commands

A-4

description

A-4

summary

A-4

V
Value Small and Branch Office feature set
Value Telecommuter feature set

1-4

voice operations
caution about delays

4-4

caution about regulation of VoIP operations

4-4

classes of service (CoS)
description

4-1

H.323 support

4-2

overview (figure)
SGCP support

4-3

4-2

supported codings

4-4

Voice over IP
See VoIP
VoIP
caution about delays

4-4

classes of service (CoS)

4-5

introduction
overview (figure)

4-3

support
supported codings

4-4

voip dial peer group command

1-8

Cisco uBR924 Software Configuration Guide
OL-0337-05 (8/2002)

IN-5

Index

Cisco uBR924 Software Configuration Guide

IN-6

OL-0337-05 (8/2002)

Source Exif Data:

File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.3
Linearized                      : No
Page Count                      : 134
Page Mode                       : UseOutlines
Format                          : application/pdf
Title                           : Cisco uBR924 Router Software Configuration Guide
Producer                        : iText 1.4.1 (by lowagie.com)
Modify Date                     : 2002:07:31 10:13:02-07:00
Concept                         : TechnicalSupport:Technical Support
Keywords                        : 
Doc Type                        : TSD Island of Content
Creator                         : FrameMaker 5.5.6p145
Create Date                     : 2002:07:30 15:30:48
Content Type                    : cisco.com#US#postSales
Date                            : 2000-11-27T00:00:00.000-08:00
Access Level                    : Guest,Customer,Partner
Country                         : US
Description                     : 
Ia Path                         : cisco.com#TechnicalSupport#Technical Support
Language                        : en
Secondary Concept               :

EXIF Metadata provided by EXIF.tools

Cisco UBR924 Router Software Configuration Guide Systems Network Scg924bk

Navigation menu

Versions of this User Manual:

Views

Navigation