EPC User Guide

EPC_User_Guide

User Manual: Pdf

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Page Count: 40

1 Introduction
- 1.1 Overview
- 1.2 Deployment scenario
2 EPC Installation
The Better String Library (http://bstring.sourceforge.net/)
Libgtpnl
3 Supported scenarios in EPC
4 Annex A: Tools for observing, debugging.
5 Annex B: GTP fragmentation.

EPC User’s Guide

Editor: EURECOM

Deliverable nature: Public

Due date:

Delivery date: August, 2016

Version: 0.12

Total number of pages: 40

Reviewed by:

Keywords: EPC, LTE, MME, S-GW, P-GW, HSS, S1AP, DIAMETER

Abstract

The deliverable presents the EPC developed by EURECOM, its configuration, installation testing and

running.

List of authors

Company Authors

EURECOM Christian BONNET, Lionel GAUTHIER, Rohit GUPTA, Florian

KALTENBERGER, Raymond KNOPP, Adlen Ksentini, Navid NIKAIEN,

Cedric ROUX.

OPEN CELLS Laurent THOMAS.

Page 2 of (40) ©

History

Modified by Date Version Comments

Lionel GAUTHIER 09/06/2015 0.1 Initial Draft

Lionel GAUTHIER 11/06/2015 0.2 Minor corrections

Lionel GAUTHIER 20/07/2015 0.3 Changes in dir and file names for git repo

Lionel GAUTHIER 29/07/2015 0.4 Minor corrections (build, get sources from git)

Lionel GAUTHIER 09/09/2015 0.5 Minor corrections (build_epc script)

Lionel GAUTHIER 21/09/2015 0.6 History, GTP-U installation for EPC

Lionel GAUTHIER 14/12/2015 0.7 Removed epc config file when eNB and EPC are

co-located, added description of S1AP scenario

replay

Lionel GAUTHIER 22/02/2016 0.8 Move from docx with embedded Visio drawings

to odt format. Align the documentation to tag

v0.2.0 of develop and master branches on

https://gitlab.eurecom.fr/oai/openair-cn

Lionel GAUTHIER 06/04/2016 0.9 Align the documentation to commit

5e1289bd506f33a1bbf196d55c86641021ccca70

of “unstable” branch

https://gitlab.eurecom.fr/oai/openair-cn

Lionel GAUTHIER 07/05/2016 0,10 Updated section “S1AP scenario replay”

Lionel GAUTHIER 07/25/2016 0.11 Add generation of certificates

Lionel GAUTHIER 08/03/2016 0.12 Updated for GTP kernel 4.7.

Page 3 of (40) ©

Table of Contents

Introduction...........................................................................................................................................8

Overview............................................................................................................................................8

Deployment scenario..........................................................................................................................8

EPC Installation...................................................................................................................................10

Operating system..............................................................................................................................10

EPC source code..............................................................................................................................10

Get the code without login............................................................................................................10

Get the code with login (contributors)..........................................................................................10

Additional software..........................................................................................................................11

The Better String Library (http://bstring.sourceforge.net/)..................................................................12

Libgtpnl...............................................................................................................................................12

HSS..................................................................................................................................................13

HSS pre-installation......................................................................................................................13

Mysql server installation..........................................................................................................13

Phpmyadmin installation details..............................................................................................13

HSS configuration........................................................................................................................15

Step 1.......................................................................................................................................15

Step 2.......................................................................................................................................16

Step 3.......................................................................................................................................16

Step 4.......................................................................................................................................16

HSS build.....................................................................................................................................16

HSS run........................................................................................................................................17

First run....................................................................................................................................17

Later runs.................................................................................................................................20

MME................................................................................................................................................21

MME pre-installation...................................................................................................................21

MME configuration......................................................................................................................21

Step 1.......................................................................................................................................21

MME section...........................................................................................................................21

SGW section............................................................................................................................24

Step 2.......................................................................................................................................24

Step 3.......................................................................................................................................24

MME build...................................................................................................................................25

Before MME first run...................................................................................................................25

MME run......................................................................................................................................25

SP_GW............................................................................................................................................26

SP-GW pre-installation.................................................................................................................26

SP-GW configuration...................................................................................................................26

Step 1.......................................................................................................................................26

SGW section............................................................................................................................26

Network interfaces section............................................................................................................26

PGW section............................................................................................................................27

Page 4 of (40) ©

SPGW run.....................................................................................................................................28

Supported scenarios in EPC.................................................................................................................29

E-UTRAN Initial attach...................................................................................................................29

Attach with IMSI..........................................................................................................................29

Attach with GUTI.........................................................................................................................29

Tracking Area Update procedures....................................................................................................29

Routing Area Update procedures......................................................................................................29

Service Request procedures..............................................................................................................29

UE triggered Service Request.......................................................................................................29

Network triggered Service Request..............................................................................................29

S1 Release procedure.......................................................................................................................29

GUTI Reallocation procedure..........................................................................................................29

Detach procedure.............................................................................................................................29

UE-Initiated Detach procedure for E-UTRAN.............................................................................29

MME-Initiated Detach procedure for E-UTRAN.........................................................................29

HSS-Initiated Detach procedure for E-UTRAN...........................................................................29

HSS User Profile management function procedure..........................................................................29

Bearer deactivation...........................................................................................................................30

PDN GW initiated bearer deactivation.........................................................................................30

MME initiated Dedicated Bearer Deactivation.............................................................................30

Intra E-UTRAN handover................................................................................................................30

Annex A: Tools for observing, debugging...........................................................................................31

Wireshark/tshark..............................................................................................................................31

Mscgen.............................................................................................................................................31

S1AP scenario replay.......................................................................................................................33

Overall process.............................................................................................................................33

Step0: Install required software on the “scenario replay”testbed..................................................33

openairinterface5g installation.................................................................................................33

openair-cn installation..............................................................................................................34

openair-cn-scenarios installation..............................................................................................34

Step1: Flowchart of network capture on S1-C..............................................................................34

Step2: Generate a generic scenario...............................................................................................37

Step3: Create configuration files for the “scenario replay” testbed...............................................37

Replay a S1AP generic scenario...................................................................................................39

Annex B: GTP fragmentation..............................................................................................................40

Page 5 of (40) ©

Index of Tables

Table 1: 3rd party software.......................................................................................................12

Table 2: HSS configuration fields............................................................................................16

Table 3: SQL Table structure mmeidentity...............................................................................18

Table 4: SQL Table structure pdn.............................................................................................19

Table 5: SQL Table structure users...........................................................................................20

Table 6: MME configuration main section...............................................................................22

Table 7: MME configuration subsection ITTI.........................................................................22

Table 8: MME configuration subsection S6a...........................................................................22

Table 9: MME configuration subsection SCTP.......................................................................22

Table 10: MME configuration subsection S1AP......................................................................22

Table 11: MME configuration subsection GUMMEI...............................................................22

Table 12: MME configuration subsection TAI LIST...............................................................23

Table 13: MME configuration subsection NAS.......................................................................23

Table 14: MME configuration subsection Network Interfaces................................................23

Table 15: MME configuration subsection Network Interfaces................................................24

Table 16: MME configuration section SGW............................................................................24

Table 17: S-GW configuration subsection Network Interfaces................................................26

Table 18: MME configuration subsection ITTI.......................................................................27

Table 19: MME configuration subsection Network Interfaces................................................27

Table 20: P-GW configuration main section............................................................................27

Table 21: P-GW configuration subsection Network Interfaces................................................28

Table 22: P-GW configuration subsection IP Address Pool Selection.....................................28

Page 6 of (40) ©

Abbreviations

3GPP Third Generation Partnership Project.

APN Access Point Name.

CIDR Classless Inter-Domain Routing.

eNB e Node B.

EPC Evolved Packet Core.

EPS Evolved Packet System.

FQDN Fully qualified domain name.

HSS Home Subscriber Server.

IMEI International Mobile Station Equipment Identity.

IMEISV International Mobile Station Equipment Identity Software

Version.

LTE Long Term Evolution.

MME Mobility Management Entity.

MSISDN Mobile Station International Subscriber Directory Number.

NW Network.

P-GW PDN Gateway, Packet Data Network Gateway.

PDN Packet Data Network.

QoS Quality of Service.

SCTP Stream Control Transmission Protocol.

S-GW Serving Gateway.

SIM Subscriber Identity Module.

TCP Transmission Control Protocol.

USIM Universal Subscriber Identity Module.

Page 7 of (40) ©

1 Introduction

1.1 Overview

The EURECOM EPC is a bundle of software components that provides the MME, S+P-GW, HSS functions of

the LTE core EPC architecture (http://www.3gpp.org/DynaReport/23002.htm).

Figure 1 EURECOM core network entities overview

The link to other network entities such as a SGSN, PCRF is actually studied.

1.2 Deployment scenario

One deployment scenario is considered with the EURECOM EPC.

Actually the SGW and the PGW are merged together, there is no S5/S8 interfaces between the two functional

entities.

The MME is a network entity that can be deployed on its own host or can be co-located with any other LTE

network entity (SPGW, HSS). Even if it works we do not recommand the deployment of the MME on a eNB.

The SPGW is a network entity that can be deployed on its own host or can be co-located with the MME or/and

with the HSS.

Page 8 of (40) ©

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2 EPC Installation

2.1 Operating system

The EPC software has only been tested on UBUNTU 14.04x64 LINUX distribution on Intel x86 64 bits

platforms. Actually on the host running the SP-GW, the GTPv1-U implementation requires that your host run a

kernel version greater or equal to 4.7 (we use 4.7-rc7).

2.2 EPC source code

Important!

In this document OPENAIRCN_DIR is the path to the EPC source code top directory (i.e. openair-cn

working directory).

It is assumed that you are logged onto your machine(s) as a non root user and you configured your system

to be a sudoer user.

The EPC software can be obtained from our git server. You will need a git client to get the sources.

If git is not installed on your computer, execute in a shell the following command (Ubuntu):

user@host:~ sudo apt-get install git

Configure git with your name/email address (only important if you are developer and want to checkin code to

Git):

git config --global user.name "Your Name"

git config --global user.email "Your email address"

Add a certificate from gitlab.eurecom.fr to your Ubuntu 14.04 installation (you need to be root user):

root@host:~# echo -n | openssl s_client -showcerts -connect gitlab.eurecom.fr:443 2>/dev/null |

sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' >> /etc/ssl/certs/ca-certificates.crt

Important!

In this document OPENAIRCN_DIR is the path to the EPC source code top directory (i.e. openair-cn working

directory).

2.2.1 Get the code without login

In order to checkout the Git repository (for OAI Users without login to gitlab server)

user@host:~ git clone https://gitlab.eurecom.fr/oai/openair-cn.git

2.2.2 Get the code with login (contributors)

In order to check out the Git repository (for OAI Developers/admins with login to gitlab server)

Please send an email to openair_tech@eurecom.fr to be added to the repository as a developer (only important

for users who want to commit code to the repository). If you do not have an account on gitlab.eurecom.fr, please

Checkout with using ssh keys:

Page 10 of (40) ©

You will need to put your ssh keys in https://gitlab.eurecom.fr/profile/keys to access to the git repo. Once that is

done, checkout the git repository using:

git clone git@gitlab.eurecom.fr:oai/openair-cn.git

Checkout with user name/password prompt:

git clone https://YOUR_USERNAME@gitlab.eurecom.fr/oai/openair-cn.git

2.3 Additional software

Some software installations have to be done prior to build the core network entities.

Please find for information, bellow a summary of third party software included in source tree or that must be

installed prior to EPC components compilation.

Installed software MME entity S/P-GW entity HSS entity Licence

UBUNTU packages Removed packages:

libgnutls-dev

'libgnutlsxx2?' nettle-dev

nettle-bin.

build/dev/debug tools:

autoconf automake bison

build-essential cmake

cmake-curses-gui

doxygen doxygen-gui

flex gccxml gdb git pkg-

config subversion

valgrind Kcachegrind.

Network tools:

ethtool iperf iproute vlan

tshark

Libraries:

guile-2.0-dev libconfig8-

dev libgcrypt11-dev

libgmp-dev libhogweed2

libgtk-3-dev libidn2-0-

dev libidn11-dev

libpthread-stubs0-dev

libsctp1 libsctp-dev

libssl-dev libtool libxml2

libxml2-dev mscgen

openssl python.

Others:

check phpmyadmin

python-dev python-

pexpect unzip

build/dev/debug tools:

autoconf, automake, bison,

build-essential, cmake,

cmake-curses-gui, doxygen,

doxygen-gui, flex, gccxml,

gdb, git, pkg-config,

subversion.

Removed packages:

libgnutls-dev 'libgnutlsxx2?'

nettle-dev nettle-bin.

Removed packages:

libgnutls-dev

'libgnutlsxx2?' nettle-

dev nettle-bin.

build/dev/debug tools:

autoconf automake

bison build-essential

cmake cmake-curses-

gui doxygen doxygen-

gui flex gdb pkg-config.

git subversion.

Libraries:

libconfig8-dev

libgcrypt11-dev libidn2-

0-dev libidn11-dev

libmysqlclient-dev

libpthread-stubs0-dev

libsctp1 libsctp-dev

libssl-dev libtool mysql-

client mysql-server

openssl.

Others:

phpmyadmin python-

pexpect

...

Nettle

(ftp://ftp.lysator.liu.se

/pub/security/lsh/nettl

e-2.5.tar.gz)

Yes

Dependancy:

autoconf automake build-

essential libgmp-dev.

No Yes LGPL

Gnutls

( ftp://ftp.gnutls.org/g

crypt/gnutls/v3.1/gnu

tls-3.1.23.tar.xz )

Yes

Dependancy:

autoconf automake build-

essential

libtasn1-6-dev libtasn1-6-

dbg libp11-kit-dev

libp11-kit0-dbg libtspi-

dev libtspi1 libidn2-0-dev

libidn11-dev

No Yes LGPLv2.1+

Page 11 of (40) ©

Installed software MME entity S/P-GW entity HSS entity Licence

FreeDiameter

(http://www.freediam

eter.net/hg/freeDiame

ter/archive/1.2.0.tar.g

Yes

Dependancy:

autoconf automake bison

build-essential cmake

cmake-curses-gui

debhelper flex g++ gcc

gdb libgcrypt-dev

libidn11-dev

libmysqlclient-dev libpq-

dev libsctp1 libsctp-dev

libxml2-dev mercurial

python-dev ssl-cert swig

No Yes BSD 3 clause

license. Check

subdirs for

informations:

extensions/dict_sip

extensions/app_sip

extensions/app_rad

gw/rgwx_sip.c

extensions/app_dia

meap/*

extensions/dict_mip

6a/*

extensions/dict_mi

p6i/*

extensions/dict_na

s_mipv6/*

extensions/dict_rfc

5777/*

Asn1c

(https://github.com/vl

m/asn1c/trunk

revision 1516)

Yes

Dependancy:

autoconf automake bison

build-essential flex gcc

libtool

No No BSD 2-Clause

Licence

SRC/UTILS/tree.h Yes Yes No BSD 2-Clause

Licence

SRC/UTILS/queue.h Yes Yes No BSD 3-Clause

Licence

SRC/UTILS/LFDS/li

blfds6.1.1.

(http://liblfds.org/)

Yes Yes No No license

SRC/GTPV2-

C/nwgtpv2c-0.11

Yes Yes No Free licence

xtables_addons

patched for OAI

(https://gitlab.eureco

m.fr/oai/xtables-

addons-oai.git)

No Yes

Dependancy:

autoconf automake build-

essential dkms iptables

iptables-dev linux-headers.

Run a kernel version equal

to 3.19 (we use 3.19.0-28)

No GPLv2

The Better String

Library

(http://bstring.sourcef

orge.net/)

Yes Yes No BSD 3-Clause

Licence

Libgtpnl

(http://git.osmocom.o

rg/libgtpnl/)

No Yes No GNU

LESSER

GENERAL

PUBLIC

LICENSE

Version 2.1

Table 1: 3rd party software

Page 12 of (40) ©

These softwares will mostly be installed by helper scripts, this will be described in following sections.

2.4 HSS

2.4.1 HSS pre-installation

In OPENAIRCN_DIR/SCRIPTS directory, execute the following command:

user@hss-host:~/openair-cn/SCRIPTS$ ./build_hss -i

This command will install the required softwares on your host.

Find bellow some hints for some interactive software installations (mysql-server, phpmyadmin).

2.4.1.1 Mysql server installation

Enter here a password for root user, lets call it MS_PW_ROOT.

Figure 3 Mysql installation root password

Figure 4 Mysql installation root password repeat

The mysql-server installation process ends here.

2.4.1.2 Phpmyadmin installation details

You should prefer the easiest way

Page 13 of (40) ©

Figure 5 Phpmyadmin installation conf DB

Enter here the MS_PW_ROOT.:

Figure 6 Phpmyadmin installation DB admin password

Please, enter here what will be the phpmyadmin application password, lets call it MS_PW_PHP:

Figure 7 Phpmyadmin installation application password

Figure 8 Phpmyadmin installation application password confirmation

Choose the web server that has to be configured: Apache.

Page 14 of (40) ©

Figure 9 Phpmyadmin installation web server selection

2.4.2 HSS configuration

In this section is describd the step by step configuration of the HSS, any parameter can be customized upon your

need (mysql server address, mySQL user name, mySQL password, HSS OP key, location of freeDiameter

configuration file, realm).

A template of the HSS configuration file can be found at OPENAIRCN_DIR/ETC/hss.conf. This configuration

file follows the libconfig file syntax (http://www.hyperrealm.com/libconfig).

Content of OPENAIRCN_DIR/ETC/hss.conf:

HSS :

{

## MySQL mandatory options

MYSQL_server = "127.0.0.1";

MYSQL_user = "@MYSQL_user@";

MYSQL_pass = "@MYSQL_pass@";

MYSQL_db = "oai_db";

## HSS options

OPERATOR_key = "1006020f0a478bf6b699f15c062e42b3"; # OP key for oai_db.sql

RANDOM = "true";

## Freediameter options

FD_conf = "/usr/local/etc/oai/freeDiameter/hss_fd.conf";

};

2.4.2.1 Step 1

Copy the file OPENAIRCN_DIR/ETC/hss.conf in /usr/local/etc/oai directory:

user@ hss- host:~/openair-cn/SCRIPTS$ sudo mkdir -p /usr/local/etc/oai/freeDiameter

user@ hss- host:~/openair-cn/SCRIPTS$ sudo cp $OPENAIRCN_DIR/ETC/hss.conf \

/usr/local/etc/oai

Please take care of the permissions of your hss.conf file.

Then customize your copied HSS configuration file:

Parameter Type

MYSQL_server String IP address of the MySQL server instance where the HSS DB is stored.

MYSQL_user String, user login HSS administrator login, could be “hssadmin”.

Page 15 of (40) ©

MYSQL_pass String, password HSS administrator password, should be MS_PW_PHP.

MYSQL_db String, database name Database name, default is oai_db for EURECOM subscribers.

OPERATOR_key String Operator key in plain text.

RANDOM String, allowed values

“yes”, “no”.

Default value is “true”. Set false when you want to capture or replay S1-C scenarios.

FD_conf String Path to HSS freeDiameter configuration file.

Table 2: HSS configuration fields

2.4.2.2 Step 2

Copy the files OPENAIRCN_DIR/ETC/hss_fd.conf, OPENAIRCN_DIR/ETC/acl.conf in

/usr/local/etc/oai/freeDiameter directory:

user@ hss- host:~/openair-cn/SCRIPTS$ sudo cp $OPENAIRCN_DIR/ETC/acl.conf

$OPENAIRCN_DIR/ETC/hss_fd.conf /usr/local/etc/oai/freeDiameter

Please take care of the permissions of your configuration files.

Then customize your copied hss_fd.conf, acl.conf configuration files if necessary, if you follow this document,

it should not be necessary, otherwise please refer to freeDiameter documentation.

2.4.2.3 Step 3

A FQDN has to be set for the HSS (see hss_fd.conf). An easy way to do that is to fill this FQDN in the /etc/hosts

file:

For example on a host with hostname 'yang':

yang@yang:$ cat /etc/hosts

127.0.0.1 localhost

127.0.1.1 yang.openair4G.eur yang #Your hostname here

127.0.1.1 hss.openair4G.eur hss

2.4.2.4 Step 4

Generate HSS certificates:

user@ hss- host:~/openair-cn/SCRIPTS$

./check_hss_s6a_certificate /usr/local/etc/oai/freeDiameter hss.openair4G.eur

2.4.3 HSS build

HSS can be built in two different ways: an executable that can run in a controlling terminal, or a daemon that

run in the background.

In OPENAIRCN_DIR/SCRIPTS directory, depending on the chosen target execute the following command:

user@hss-host:~/openair-cn/SCRIPTS$ ./build_hss --clean --debug

user@hss-host:~/openair-cn/SCRIPTS$ ./build_hss --clean --debug --daemon

This command will compile the right target oai_hss or oai_hssd.

Page 16 of (40) ©

2.4.4 HSS run

In OPENAIRCN_DIR/SCRIPTS directory, a helper script called run_hss is provided for running the HSS.

Here are the run_hss options:

./run_hss -h

Usage: run_hss [OPTION]...

Run the HSS executable (experimental).

Options:

Mandatory arguments to long options are mandatory for short options too.

-c, --config-file filename Config file to be used by HSS if you don't want to use the

default one: /usr/local/etc/oai/hss.conf

-e, --export-db filename Export current database to a SQL file, file prefix is

$OPENAIRCN_DIR/SRC/OAI_HSS/db. (useful for replaying test scenarios)

-D, --daemon Run the daemon.

-i, --import-db filename Import SQL file to current database, file prefix is

$OPENAIRCN_DIR/SRC/OAI_HSS/db. (useful for replaying test scenarios or restoring original

database content)

-I, --install-hss-files Install HSS config files.

-g, --gdb Run with GDB.

-h, --help Print this help.

-k, --kill Kill the running local HSS.

2.4.4.1 First run

2.4.4.1.1 Customize HSS database content

SQL operations (display, update, export, etc) can be done easily with the help of phpMyAdmin, you have to

open the following URL with your browser: http://yourhsshost/phpmyadmin.

Otherwise you can use any other MySQL tool, script compatible with MySQL.

The steps for adding a subscriber are the following:

- Add your MME(s) in table mmeidentity

- Add subscriber(s) in table users

user.imsi=IMSI of your USIM.

user.msisdn= MSISDN of your USIM (unused).

users.imei=NULL

users.imei_sv=NULL

users.ms_ps_status=’PURGED’

users.rau_tau_timer=120

users.ue_ambr_ul=50000000

users.ue_ambr_dl=100000000

users.access_restriction=47

users.mme_cap=0

Page 17 of (40) ©

users.mmeidentity_idmmeidentity=’your MME key’

users.RFSP-Index=1

users.urrp_mme=0

users.sqn=’your USIM programmed SQN’

users.rand=0

users.OPc=’the OPc key’ (will be computed by the oai_hss executable)

- Add subscriber(s) in table pdn.

Table mmeidentity:

Structure:

Field Type Null Key Default Extra

idmmeidentity int(11) NO PRI NULL auto_increment

mmehost varchar(255) YES NULL

mmerealm varchar(200) YES NULL

UE-Reachability tinyint(1) NO NULL

Table 3: SQL Table structure mmeidentity

Column idmmeIdentity is the primary key of a MME.

Column mmehost contains the FQDN of a MME.

Column mmerealm contains the realm of a MME.

Example of content:

+---------------+------------------------+---------------+-----------------+

+---------------+------------------------+---------------+-----------------+

| 2 | yang.openair4G.eur | openair4G.eur | 0 |

| 1 | ng40-erc.openair4G.eur | openair4G.eur | 0 |

| 3 | ABEILLE.openair4G.eur | openair4G.eur | 0 |

+---------------+------------------------+---------------+-----------------+

Table pdn:

This table contains mainly the association between a subscriber (users_imsi) and a APN (apn), and its QOS

parameters.

Structure:

Field Type Null Key Default Extra

id int(11) NO PRI NULL auto_increment

apn varchar(60) NO NULL

pdn_type enum('IPv4','IPv6','IPv4v6','IPv4_or_IPv6') NO NULL

pdn_ipv4 varchar(15) YES NULL 0.0.0.0

pdn_ipv6 varchar(45) YES NULL 0:0:0:0:0:0:0:0

aggregate_ambr_ul int(10) unsigned YES 50000000

aggregate_ambr_dl int(10) unsigned YES 100000000

Page 18 of (40) ©

pgw_id int(11) NO PRI NULL

users_imsi varchar(15) NO PRI

qci tinyint(3) unsigned NO 9

priority_level tinyint(3) unsigned NO 15

pre_emp_cap enum('ENABLED','DISABLED') YES DISABLED

pre_emp_vul enum('ENABLED','DISABLED') YES DISABLED

LIPA-Permissions enum('LIPA-prohibited','LIPA-only','LIPA-

conditional')

YES LIPA-only

Table 4: SQL Table structure pdn

Column id is the primary key of a pdn entry.

Column pdn_type contains the type of PDN, actually only IPv4 is supported.

Column pdn_ipv4 contains the IPv4 address of the PDN (unused).

Column pdn_ipv6 contains the IPv6 address of the PDN (unused).

Column aggregate_ambr_ul TODO

Column aggregate_ambr_dl TODO

Column pgw_id TODO

Column users_imsi TODO

Column qci TODO

Column priority_level TODO

Column pre_emp_capability TODO

Column pre_emp_vulnerability TODO

Column LIPA_Permissions TODO

Table users

This table contains mainly the informations about a subscriber: its IMSI, IMEI, key LTE K, SQN, operator key

OP, QOS parameters, the last known MME identity where the subscriber registered.

Structure:

Field Type Null Key Default Extra

imsi varchar(15) NO PRI NULL

msisdn varchar(46) YES NULL

imei varchar(15) YES NULL

imei_sv varchar(2) YES NULL

ms_ps_status enum('PURGED','NOT_PURGED') YES PURGED

rau_tau_timer int(10) unsigned YES 120

ue_ambr_ul bigint(20) unsigned YES 50000000

ue_ambr_dl bigint(20) unsigned YES 100000000

access_restriction int(10) unsigned YES 60

mme_cap int(10) unsigned zerofill YES NULL

mmeidentity_idmmeidentity int(11) NO PRI 0

key varbinary(16) NO 0

RFSP-Index smallint(5) unsigned NO 1

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urrp_mme tinyint(1) NO 0

sqn bigint(20) unsigned zerofill NO NULL

rand varbinary(16) NO NULL

OPc varbinary(16) YES NULL

Table 5: SQL Table structure users

TODO column description.

2.4.4.2 Later runs

By default (otherwise you know what you are doing) for all following runs of the HSS, use:

user@hss-host:~/openair-cn/SCRIPTS$ ./run_hss

user@hss-host:~/openair-cn/SCRIPTS$ ./run_hss --daemon

Page 20 of (40) ©

2.5 MME

2.5.1 MME pre-installation

In OPENAIRCN_DIR/SCRIPTS directory, execute the following command:

user@mme-host:~/openair-cn/SCRIPTS$ ./build_mme -i

This command will install the required softwares on your host.

2.5.2 MME configuration

A template of the MME configuration file can be found at OPENAIRCN_DIR/ETC/mme.conf. This

configuration file follows the libconfig file syntax (http://www.hyperrealm.com/libconfig).

2.5.2.1 Step 1

Copy the file OPENAIRCN_DIR/ETC/mme.conf in /usr/local/etc/oai directory:

user@mme- host:~/openair-cn/SCRIPTS$ sudo mkdir -p /usr/local/etc/oai/freeDiameter

user@mme- host:~/openair-cn/SCRIPTS$ sudo cp $OPENAIRCN_DIR/ETC/mme.conf

/usr/local/etc/oai

Please take care of the permissions of your mme.conf file.

Then customize your copied MME configuration file:

2.5.2.2 MME section

Parameter Type

RUN_MODE String Allowed values: “OTHER”, “TEST”. Set “OTHER” for normal operations,

set “TEST” for S1C scenario player.

REALM String Diameter realm of the MME, default is openair4G.eur.

MAXENB Num/Integer Maximum number of eNB that can connect to MME.

MAXUE Num/Integer For debug purpose, used to restrict the number of served UEs the MME can

handle.

RELATIVE_CAPACITY Num/Integer Even though this parameter is not used by the MME for controlling the

MME load balancing within a pool (at least for now), the parameter has to

be forwarded to the eNB during association procedure. Values going from 0

to 255, (Default value is 15)

MME_STATISTIC_TIMER Num/Integer Displayed statistic period in logs.

EMERGENCY_ATTACH_SUPPORTED String Actually only “no” is supported

UNAUTHENTICATED_IMSI_SUPPORTED String Actually only “no” is supported

EPS_NETWORK_FEATURE_SUPPORT_IMS_V

OICE_OVER_PS_SESSION_IN_S1

String Actually only “no” is supported

EPS_NETWORK_FEATURE_SUPPORT_EMER

GENCY_BEARER_SERVICES_IN_S1_MODE

String Actually only “no” is supported

EPS_NETWORK_FEATURE_SUPPORT_LOCA

TION_SERVICES_VIA_EPC

String Actually only “no” is supported

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EPS_NETWORK_FEATURE_SUPPORT_EXTE

NDED_SERVICE_REQUEST

String Actually only “no” is supported

IP_CAPABILITY String Actually only IPV4 is supported, (Choice between IPV4, IPV4V6,

IPV4ORV6)

Table 6: MME configuration main section

2.5.2.2.1 INTERTASK_INTERFACE subsection

Parameter Type

ITTI_QUEUE_SIZE Num/Integer Upper bound for the message queue size expressed in bytes (all messages exchanged by tasks have the

same size). Restrict the number of messages in queues or detect a possible MME overload.

Table 7: MME configuration subsection ITTI

2.5.2.2.2 S6A subsection

Parameter Type

S6A_CONF String FreeDiameter MME config file path, default value is

“/usr/local/etc/oai/freeDiameter/mme_fd.conf”.

HSS_HOSTNAME String HSS hostname, default value is “hss”.

Table 8: MME configuration subsection S6a

2.5.2.2.3 SCTP subsection

Parameter Type

SCTP_INSTREAMS Num/Integer Maximum number of SCTP input streams allowed for a S1-C connection.

SCTP_OUTSTREAMS Num/Integer Maximum number of SCTP output streams allowed for a S1-C connection.

Table 9: MME configuration subsection SCTP

2.5.2.2.4 S1AP subsection

Parameter Type

S1AP_OUTCOME_TIMER Num/Integer Once an outcome is sent from MME to eNB, the MME locally starts a timer to abort the

procedure and release UE context if the expected answer to this outcome is not received at the

expiry of this timer. This timer is expressed in seconds. (Default value = 5 seconds)

Table 10: MME configuration subsection S1AP

2.5.2.2.5 GUMMEI LIST subsection

This section contains the GUMMEIs of the MME, actually only one GUMMEI is supported.

Parameter Type

{MCC, MNC,

MME_GID,

MME_CODE}

String/String/String/String Mobile country code of GUMMEI, Mobile network code of GUMMEI, MME group ID

of GUMMEI, MME code of GUMMEI

Table 11: MME configuration subsection GUMMEI

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2.5.2.2.6 TAI LIST subsection

The content of this section should be consistent with content of GUMMEI LIST section (MCC/MNC)

Parameter Type

{MCC/MNC/TAC} String/String/String Each entry of the list is a triplet of a MCC, MNC and TAC. There can be up to 16

tracking areas identity set in this list. Actually we do not support shared networks, so

the MCC/MNC field should all be equal among the list

Table 12: MME configuration subsection TAI LIST

2.5.2.2.7 NAS subsection

Parameter Type

ORDERED_SUPPORTED_INTEGRITY_ALGORITHM_LIST Array of String Preference list in decreasing order of supported integrity

algorithms, actually supported integrity algorithms are

EIA0, EIA1, EIA2

ORDERED_SUPPORTED_CIPHERING_ALGORITHM_LIST Array of String Preference list in decreasing order of supported integrity

algorithms, actually supported integrity algorithms are

EEA0, EEA1, EEA2

T3402 Integer EMM timer, duration in minutes.

T3412 Integer EMM timer, duration in minutes.

T3485 Integer ESM timer, duration in seconds, unused (TODO).

T3486 Integer ESM timer, duration in seconds, unused (TODO).

T3489 Integer ESM timer, duration in seconds, unused (TODO).

T3495 Integer ESM timer, duration in seconds, unused (TODO).

Table 13: MME configuration subsection NAS

2.5.2.2.8 Network interfaces subsection

Parameter Type

MME_INTERFACE_NAME_FOR_S1_MME String Interface name for S1-MME (S1-C), this interface name can

be a real ethernet interface or a virtual ethernet interface. The

script run_mme can configure it and bring it up if you

provide the -i/--set-nw-interfaces option.

MME_IPV4_ADDRESS_FOR_S1_MME String, CIDR Binded address for S1-MME

MME_INTERFACE_NAME_FOR_S11_MME String Interface name for S11, this interface name can be a real

ethernet interface or a virtual ethernet interface. The script

run_mme can configure it and bring it up if you provide the

-i/--set-nw-interfaces option.

MME_IPV4_ADDRESS_FOR_S11_MME String, CIDR Binded address for S11.

Table 14: MME configuration subsection Network Interfaces

2.5.2.2.9 Logging subsection

Parameter Type

OUTPUT String choice in { "CONSOLE", "UNBUFFERED_CONSOLE", "`path to file`",

"`IPv4@`:`TCP port num`"}.

Choise "CONSOLE" means that logs go to STDOUT, STDERR in a manner

that even if multiple concurrent threads dump a lot of logs, traces cannot

Page 23 of (40) ©

overlap (the cost here is that we need buffering).

Choice "UNBUFFERED_CONSOLE" means that logs go directly to

STDOUT, STDERR, traces may overlap.

Choice "`path to file`", for example “/tmp/mme.log” is a file receiving the

dump of logs without overlaping traces.

Choice "`IPv4@`:`TCP port num`" (for example “192.168.12.17:6789”)

dump the logs towards a TCP server. The logs cat be easily displayed or

dumped into a file with netcat (nc -kl 6789).

COLOR String Choice in { "yes", "no" } means use of ANSI styling codes or no. TODO

SCTP_LOG_LEVEL String Log level choice in { "EMERGENCY", "ALERT", "CRITICAL", "ERROR",

"WARNING", "NOTICE", "INFO", "DEBUG", "TRACE"}

S1AP_LOG_LEVEL String Idem as above

NAS_LOG_LEVEL String Idem as above

MME_APP_LOG_LEVEL String Idem as above

S6A_LOG_LEVEL String Idem as above

UTIL_LOG_LEVEL String Idem as above

MSC_LOG_LEVEL String Idem as above

ITTI_LOG_LEVEL String Idem as above

ASN1_VERBOSITY String Choice in {“none”, “info”, “annoying”}

Table 15: MME configuration subsection Network Interfaces

2.5.2.3 SGW section

The PGW, SGW selections are not implemented yet, so we need a mechanism that replace these selection: yet,

we only support one PDN, one PGW, one SGW.

2.5.2.3.1 Network interfaces subsection

Parameter Type

SGW_IPV4_ADDRESS_FOR_S11 String, CIDR Binded SGW address for S11.

Table 16: MME configuration section SGW

2.5.2.4 Step 2

Copy the file OPENAIRCN_DIR/ETC/mme_fd.conf in /usr/local/etc/oai/freeDiameter directory:

user@ hss- host:~/openair-cn/SCRIPTS$ sudo mkdir -p /usr/local/etc/oai/freeDiameter

user@ hss- host:~/openair-cn/SCRIPTS$ sudo cp $OPENAIRCN_DIR/ETC/mme_fd.conf

/usr/local/etc/oai/freeDiameter

Please take care of the permissions of your configuration files.

Then customize your copied mme_fd.conf configuration files (Identity value, realm), please refer to

freeDiameter documentation.

2.5.2.5 Step 3

A FQDN has to be set for the MME (see mme_fd.conf). An easy way to do that is to set this FQDN in the

/etc/hosts file:

For example on a host with hostname 'yang':

yang@yang:$ cat /etc/hosts

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127.0.0.1 localhost

127.0.1.1 yang.openair4G.eur yang # MME host

127.0.1.1 hss.openair4G.eur hss # HSS located on MME host

2.5.3 MME build

MME can be built in two different ways: an executable that can run in a controlling terminal, or a daemon that

run in the background.

In OPENAIRCN_DIR/SCRIPTS directory, depending on the chosen target execute the following command:

user@mme-host:~/openair-cn/SCRIPTS$ ./build_mme --clean

user@mme-host:~/openair-cn/SCRIPTS$ ./build_mme --clean --daemon

This command will compile the right target oai_mme or oai_mmed.

2.5.4 Before MME first run

Prior the first run of the MME, you will have to generate certificates:

user@hss-host:~/openair-cn/SCRIPTS$./check_mme_s6a_certificate

/usr/local/etc/oai/freeDiameter yang.openair4G.eur

2.5.5 MME run

In OPENAIRCN_DIR/SCRIPTS directory, a helper script called run_mme is provided for running the MME.

user@hss-host:~/openair-cn/SCRIPTS$ ./run_mme

user@hss-host:~/openair-cn/SCRIPTS$ ./run_mme --daemon

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2.6 SP_GW

2.6.1 SP-GW pre-installation

First install a 4.7 linux kernel, even from source from kernel.org, then select gtp to be compiled as a module,

and install the kernel and modules and boot on the 4.7 kernel

For example only

in your linux 4.7+ source tree:

make oldconfig

in .config, check that gtp is built as a module : CONFIG_GTP=m

make -jX

make modules_install

make install

Install libgtpnl from http://git.osmocom.org/libgtpnl/ and any software dependancy.

In OPENAIRCN_DIR/SCRIPTS directory, execute the following command:

user@mme-host:~/openair-cn/SCRIPTS$ ./build_spgw -i

This command will install the required softwares on your host.

2.6.2 SP-GW configuration

A template of the SP-GW configuration file can be found at OPENAIRCN_DIR/ETC/spgw.conf. This

configuration file follows the libconfig file syntax (http://www.hyperrealm.com/libconfig).

2.6.2.1 Step 1

Copy the file OPENAIRCN_DIR/ETC/mme.conf in /usr/local/etc/oai directory:

user@mme- host:~/openair-cn/SCRIPTS$ sudo mkdir -p /usr/local/etc/oai

user@mme- host:~/openair-cn/SCRIPTS$ sudo cp $OPENAIRCN_DIR/ETC/spgw.conf

/usr/local/etc/oai

Please take care of the permissions of your spgw.conf file.

Then customize your copied SP-GW configuration file:

2.6.2.2 SGW section

2.6.3 Network interfaces section

Parameter Type

SGW_INTERFACE_NAME_FOR_S11 String Interface name for S11.

SGW_IPV4_ADDRESS_FOR_S11 String, CIDR notation Binded address for S11.

SGW_INTERFACE_NAME_FOR_S1U_S12_S4_UP String Interface name for S1-U, this interface name can be a real

Page 26 of (40) ©

ethernet interface or a virtual ethernet interface. The script

run_spgw can configure it and bring it up if you provide the

-i/--set-nw-interfaces option.

SGW_IPV4_ADDRESS_FOR_S1U_S12_S4_UP String, CIDR notation Binded address for S1-U

SGW_IPV4_PORT_FOR_S1U_S12_S4_UP Num/Integer Port number for S1-U (IANA), Should be 2152

SGW_INTERFACE_NAME_FOR_S5_S8_UP String, Interface name for S5 or S8, set to “none” because unused

SGW_IPV4_ADDRESS_FOR_S5_S8_UP String, CIDR notation Binded address for S5 or S8, set to 0.0.0.0/xx because

unused

Table 17: S-GW configuration subsection Network Interfaces

2.6.3.1.1 INTERTASK_INTERFACE subsection

Parameter Type

ITTI_QUEUE_SIZE Num/Integer Upper bound for the message queue size expressed in bytes (all messages exchanged by tasks have the

same size). Restrict the number of messages in queues or detect a possible overload.

Table 18: MME configuration subsection ITTI

2.6.3.1.2 Logging subsection

Parameter Type

OUTPUT String choice in { "CONSOLE", "SYSLOG", "`path to file`", "`IPv4@`:`TCP port

num`"}.

Choise "CONSOLE" means that logs go to STDOUT, STDERR.

Choice "`path to file`", for example “/tmp/spgw.log” is a file receiving the

dump of logs.

Choice "`IPv4@`:`TCP port num`" (for example “192.168.12.18:6789”)

dump the logs towards a TCP server. The logs cat be easily displayed or

dumped into a file with netcat (nc -kl 6789).

THREAD_SAFE String Choice in { "yes", "no" }, yes means that logs cannot overlaps on output.

COLOR String Choice in { "yes", "no" } means use of ANSI styling codes or no. TODO

UDP_LOG_LEVEL String Log level choice in { "EMERGENCY", "ALERT", "CRITICAL", "ERROR",

"WARNING", "NOTICE", "INFO", "DEBUG", "TRACE"}

GTPV1U_LOG_LEVEL String Idem as above

GTPV2C_LOG_LEVEL String Idem as above

SPGW_APP_LOG_LEVEL String Idem as above

S11_LOG_LEVEL String Idem as above

Table 19: MME configuration subsection Network Interfaces

2.6.3.2 PGW section

2.6.3.2.1 Main section

Parameter Type

DEFAULT_DNS_IPV4_ADDRESS String, IPv4 dot decimal IPv4 address of primary default DNS that can be queried by UEs

DEFAULT_DNS_SEC_IPV4_ADDRE

String, IPv4 dot decimal IPv4 address of secondary default DNS that can be queried by UEs

FORCE_PUSH_PROTOCOL_CONFI String Non standard feature, normally should be set to "no", but you may need to

GURATION_OPTIONS set to yes for UE that do not explicitly request a PDN address through NAS

signalling, MTU, DNS are also pushed even if not requested.

UE_MTU Integer UE MTU to be pushed in protocol configuration options if option

“FORCE_PUSH_PROTOCOL_CONFIGURATION_OPTIONS”is set

to “yes”

Table 20: P-GW configuration main section

2.6.3.2.2 Network interfaces section

Parameter Type

PGW_INTERFACE_NAME_FOR_S5_S8 String Interface name for S5 or S8, “none” because unused

PGW_INTERFACE_NAME_FOR_SGI String Interface name for SGi

PGW_MASQUERADE_SGI String Should outgoing UE IPv4 traffic be masqueraded (source NAT), “yes” or

“no”.

UE_TCP_MSS_CLAMPING String Choice in { "yes", "no" }, “yes” should be choose if you are unable to set

the MTU on the S1U path to a value greater or equal to 1536.

If set to “yes”, then PGW_INTERFACE_NAME_FOR_S5_S8 should be

set to the same value as SGW_IPV4_PORT_FOR_S1U_S12_S4_UP.

Table 21: P-GW configuration subsection Network Interfaces

2.6.3.2.3 IP Address Pool section

Parameter Type

IPV4_LIST String, CIDR notation List of IPv4 netmasks that designate a list of available IPv4 addresses for Ues.

Actually only one pool of IP addresses is supported.

Table 22: P-GW configuration subsection IP Address Pool Selection

2.6.4 SPGW run

In OPENAIRCN_DIR/SCRIPTS directory, a helper script called run_spgw is provided for running the SPGW.

user@hss-host:~/openair-cn/SCRIPTS$ ./run_spgw -r

user@hss-host:~/openair-cn/SCRIPTS$ ./run_spgw -r --daemon

3 Supported scenarios in EPC

3.1 E-UTRAN Initial attach

3.1.1 Attach with IMSI

TODO Add MSCGEN SEQ diagram

3.1.2 Attach with GUTI

TODO Add MSCGEN SEQ diagram

3.2 Tracking Area Update procedures

TODO Add MSCGEN SEQ diagram

3.3 Routing Area Update procedures

Not supported yet.

3.4 Service Request procedures

3.4.1 UE triggered Service Request

TODO Add MSCGEN SEQ diagram

3.4.2 Network triggered Service Request

Not supported yet.

3.5 S1 Release procedure

TODO Add MSCGEN SEQ diagram

3.6 GUTI Reallocation procedure

Not supported yet.

3.7 Detach procedure

3.7.1 UE-Initiated Detach procedure for E-UTRAN

TODO Add MSCGEN SEQ diagram

3.7.2 MME-Initiated Detach procedure for E-UTRAN

3.7.3 HSS-Initiated Detach procedure for E-UTRAN

Not supported.

3.8 HSS User Profile management function procedure

Not supported.

3.9 Bearer deactivation

3.9.1 PDN GW initiated bearer deactivation

Not supported

3.9.2 MME initiated Dedicated Bearer Deactivation

Not supported yet

3.10 Intra E-UTRAN handover

Not supported yet

4 Annex A: Tools for observing, debugging.

4.1 Wireshark/tshark

You can launch wireshark instances on S1 (filter s1ap, gtpu), S6A (filter diameter, if TCP is the undelying

protocol, you can select a TCP packet relative to the DIAMETER exchange and the select decode as

DIAMETER).

4.2 Mscgen

Extract from http://www.mcternan.me.uk/mscgen/: “Mscgen is a small program that parses Message Sequence

Chart descriptions and produces PNG, SVG, EPS or server side image maps (ismaps) as the output. Message

Sequence Charts (MSCs) are a way of representing entities and interactions over some time period”…” Mscgen

aims to provide a simple text language that is clear to create, edit and understand, which can also be transformed

into common image formats for display or printing.”…

Openair use mscgen to offer another view of events (SDUs, timers, etc) that happens inside an executable and

also (still under development) PDUs exchanged between protocol entities.

Openair HSS don't have the msgen feature.

Important:

Check that mscgen traces are configured for being generated (CFLAG MESSAGE_CHART_GENERATOR set

to true in OPENAIRCN_DIR/BUILD/MME/CMakeLists.template)

You have to instruct the mme executable to dump the ITTI messages to a file with the argument -m

path_to_directory. The mscgen files will be located under the specified directory, in a directory containing the

time of the generated traces (text and png files).

Example:

Figure 9 Mscgen output example

'# 

-$ %$



$ !

#%(

)$ %

-$ %

'(0

-$ %

$ %

-# 

1(-

4.3 S1AP scenario replay

The aim of this tool is helping for MME bug reports, MME development, non-regression test, debug

purpose, it allows to replay without the help of any eNB(s) or UE(s) a S1AP scenario previously

captured as a pcap dumped file.

4.3.1 Overall process

Figure 10 Workflow of scenario replay

In order to replay a scenario, a scenario has to be played/captured (step 1), then the captured artefacts

have to processed in order to generate a generic scenario (step 2) ready to be replayed on any other

testbed (step 3).

4.3.2 Step0: Install required software on the “scenario replay”testbed

Note: If your “scenario replay” testbed and the “scenario capture testbed are the same” then step into

section 4.3.2.1“openairinterface5g installation” only.

For the ease of all operations, the targeted testbed is only one host called here “testbed”.

On the host “testbed”, clone all 3 git repositories : openairinterface5g

(git@gitlab.eurecom.fr:oai/openairinterface5g.git or

https://gitlab.eurecom.fr/oai/openairinterface5g.git), openair-cn-scenarios

(git@gitlab.eurecom.fr:oai/openair-cn-scenarios.git or https://gitlab.eurecom.fr/oai/openair-cn-

scenarios.git) and openair-cn (git@gitlab.eurecom.fr:oai/openair-cn.git or

https://gitlab.eurecom.fr/oai/openair-cn.git).

4.3.2.1 openairinterface5g installation

In the directory openairinterface5g:

user@ testbed:~/openairinterface5g$ source .oaienv

user@ testbed:~/openairinterface5g$ cd cmake_targets

user@ testbed:~/cmake_targets$ ./build_oai -I --install-optional-packages

user@ testbed:~/cmake_targets$ cd tools

user@ testbed:~/tools$ ./build_test_epc_tools --clean --debug

4.3.2.2 openair-cn installation

In openair-cn directory:

user@ testbed:~/openair-cn/SCRIPTS$ cd SCRIPTS

user@ testbed:~/openair-cn/SCRIPTS$ ./build_hss --check-installed-software

user@ testbed:~/openair-cn/SCRIPTS$ ./build_mme –check-installed-software

user@ testbed:~/openair-cn/SCRIPTS$ ./build_mme --install-gtpu-kernel-module

user@ testbed:~/openair-cn/SCRIPTS$ ./build_spgw –check-installed-software

user@ testbed:~/openair-cn/SCRIPTS$ ./build_mme --clean --daemon

user@ testbed:~/openair-cn/SCRIPTS$ ./build_spgw --clean --daemon

user@ testbed:~/openair-cn/SCRIPTS$ ./build_hss --clean --daemon

4.3.2.3 openair-cn-scenarios installation

You should set an environment variable OPENAIRCN_DIR pointing to openair-cn directory,

otherwise you will be later prompted for openair-cn directory location.

For example:

user@ testbed:~$ echo 'export OPENAIRCN_DIR=/home/user/openair-cn' >> ~/.bashrc

4.3.3 Step1: Flowchart of network capture on S1-C

The goal of this step is to capture a SCTP/S1AP trace that we want to be able to replay.

Step a: Run HSS

The HSS database has first to be configured for not generating randoms in security algorithms,

otherwise we will not be able to replay trace coming from UE(s).

In the HSS configuration file /usr/local/etc/oai/hss.conf, set RANDOM to false:

RANDOM = "false";

In order to be able to replay the scenario in the same conditions, the initial content of the database has

to be saved.

The extra argument that has to be passed in addition to other arguments to the run_hss script is:

--export-db /tmp/hss_db.sql

Step b: run MME

No change here compared to standard case.

Step c: run SP-GW

No change here compared to standard case.

Step d: start a pcap-ng capture on S1-C

This step is not automated, you have to start on your own a tool to capture the network traffic on the

S1-C network. (you can use wireshark).

VERY IMPORTANT 1: PLEASE filter the packets with the following filter string:

“s1ap or sctp.chunk_type == INIT or sctp.chunk_type == INIT_ACK or sctp.chunk_type ==

COOKIE_ECHO or sctp.chunk_type == COOKIE_ACK”.

VERY IMPORTANT 2: We need the scenario from the beginning, that means the we need to have the

SCTP INIT and SCTP INIT_ACK messages captured, so you must start the capture before lauching

the eNB(s).

Step e: start the eNB(s)

The eNB config files will be used later to make a scenario independent of IP addresses.

Step f: run your scenario

Step g: save the captured scenario

At the end of this process please save in a created subdirectory of openair-cn-

scenarios/SCENARIOS/S1 whose name reflects the test case success or failure:

- The eNB(s) config file(s) with the name “enb.conf”

- The MME config file with the name “mme.conf”

- The MME freeDiameter config file with the name “mme_fd.conf”

- The SPGW config file with the name “spgw.conf”

- The exported database SQL file with the name “hss_db.sql”.

- The pcap-ng file containing all SCTP and S1AP traffic (filtered with “s1ap or sctp.chunk_type

== INIT or sctp.chunk_type == INIT_ACK or sctp.chunk_type == COOKIE_ECHO or

sctp.chunk_type == COOKIE_ACK”) occurred on S1-C network with the name “s1.pcapng”.

- The HSS and mySQL security parameters in a file named hss_credentials.txt:

OPERATOR_KEY="youroperatorkey"

MYSQL_USER="yourdbuser"

MYSQL_PASSWORD="yourdbpassword"

Figure 11 Workflow of scenario capture

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The files listed in the flowchart figure are part of the “scenario resource files”, that means that if you

want to replay the captured S1-C scenario, they will have to be saved in a created subdirectory of

openair-cn-scenarios/SCENARIOS/S1 (on your personal git branch for most cases).

4.3.4 Step2: Generate a generic scenario

The scenario captured as a pcap file now have to be transformed in a XML file with abstracted IP

addresses.

In openair-cn-scenarios/SCRIPTS, run the following command:

user@testbed:~/openair-cn-scenarios/SCRIPTS$ ./s1_prepare_test_scenarios

This command generates a copy of the S1-C pcap scenario, but with abstract IP addresses, for

example:

...

<ip.src value="enb0_s1c"/>

<ip.dst value="mme0_s1c_0"/>

...

Figure 12 Captured scenario to generic scenario

4.3.5 Step3: Create configuration files for the “scenario replay” testbed

You have to create the network plan for the “scenario replay” testbed. The configuration files of the

LTE network entities (eNB, MME, SPGW, HSS) will be a merge of the “scenario capture” testbed

configuration files and the “scenario replay” network plan.

Figure 13 Scenario replay configuration files

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Here is the network plan used by EURECOM for replaying scenarios.

Figure 14 Proposed “replay network plan”

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After the creation of the 3 configuration files for the 3 network entities, the content of the scenario

directory should look like this example:

user@ testbed:~/EURECOM/openair-cn-scenarios/SCENARIOS/S1/NR_TESTS/PON_POFF$ ls -1

enb.conf

enb.replay.conf

enb.replay.run_options.txt

hss_credentials.txt

hss_db.replay.sql

hss_db.sql

hss_fd.conf

mme.conf

mme_fd.conf

mme.replay.conf

s1.html

s1.pcapng

s1.pdml

s1.xml

spgw.conf

spgw.replay.conf

test_epc_generate_scenario.history

4.3.6 Replay a S1AP generic scenario

For replaying a scenario open a terminal and go into directory openair-cn-scenarios/SCRIPTS and

run the following command:

user@ testbed:~/EURECOM/openair-cn-scenarios/SCRIPTS$ ./s1_run_test_scenario -S

/home/eurecom/EURECOM/openair-cn-scenarios/SCENARIOS/S1/NR_TESTS/PON_POFF

5 Annex B: GTP fragmentation.

In order to avoid GTP fragmentation on the S1-U link, we strongly suggest to increase the MTU of

S1-U network interfaces to at least 1536 (1536 + 8*x x in [0..N]).

Justification:

- IP fragmentation has an extra cost in network bandwidth, time and CPU.

- 3GPP TS 36.300 section 4.5 IP fragmentation:

Fragmentation function in IP layer on S1 and X2 shall be supported.

Configuration of S1-U (X2-U) link MTU in the eNB according to the MTU of the network

domain the node belongs to shall be considered as a choice at network deployment. The

network may employ various methods to handle IP fragmentation, but the specific methods to

use are implementation dependant.

Here is an example of a testbed successfully tested at EURECOM:

UE is Nexus 5.

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