Data Critical 00DR-10000 Network Access Points User Manual
Data Critical Corporation Network Access Points Users Manual
Contents
- 1. Users Manual
- 2. Cover Letter for Manual
Users Manual
SNAP2410/2414/2420 Spread Spectrum Network Access Points Installation Guide April 20, 2000 One Meca Way Norcross, Georgia 30093 www.digital-wireless.com (770) 564-5540 Note: This unit has been tested and found to comply with the limits for a class A digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his own expense. Commensurate with EIRP limits specified in FCC Rules 15.247b, this device may not be used with antennas that exceed 36dB of gain in point-to-point applications or 16dB of gain in multi-point applications. Transmitter Module FCCID: HSW-2410M. Table of Contents Introduction ...................................................................................................... 1 Getting Started ................................................................................................. 2 Connecting the SNAP .................................................................................... 2 SNAP Status Indicators ................................................................................. 3 Configuring the SNAP.................................................................................... 3 SNAP Operation ............................................................................................... 5 Overview ....................................................................................................... 5 TCP/IP Addresses ......................................................................................... 5 Seamless Roaming........................................................................................ 6 Synchronization ............................................................................................. 7 AP Mode Operation ....................................................................................... 7 PPP Operation .............................................................................................. 8 4-Port Hub..................................................................................................... 8 SNAP Command Set........................................................................................ 9 SNAP System Commands ............................................................................. 9 Ethernet Commands.....................................................................................10 SNAP Radio Commands...............................................................................11 AP Mode Commands....................................................................................12 PPP Mode Commands .................................................................................13 Radio Modem Configuration ............................................................................15 Radio Commands.........................................................................................15 SNAP Datagram Protocol (SDP) ......................................................................17 Overview ......................................................................................................17 SDP Header .................................................................................................17 SDP Messages.............................................................................................18 Troubleshooting ..............................................................................................21 Technical Support.........................................................................................21 Quick Reference..............................................................................................22 Specifications ..................................................................................................25 Warranty .........................................................................................................26 INTRODUCTION The SNAP2410 family of products from Digital Wireless Corporation provides Ethernet connectivity to networks of WIT2410 radios. Built around the WIT2410, SNAP products provide a 10BaseT connection to Ethernet networks and function as base stations for remote devices containing WIT2410 transceivers. By supporting seamless roaming, multiple SNAPs can be connected to a network to provide practically unlimited coverage area. To simplify system installation some SNAPs have built-in 4-port hubs with an uplink port. In addition, these SNAPs allow for power to be distributed through the hub ports. Depending on the model, SNAPs have one or two WIT2410 transceivers. Each radio can support 62 simultaneous remotes. Thus SNAPs can support up to 124 simultaneous remotes. Each remote radio has a unique ID number, so the number of remotes that can communicate with a SNAP is unlimited, subject to a limit of 62 remotes at any one time. The communication between the SNAP and the WIT2410 remotes is performed using the WIT2410 over-the-air protocol. Thus the SNAP products are 802.3 compatible but not 802.11 compatible. By using the 460Kbps over-the-air data rate the WIT2410 protocol, the full range of WIT2410 radios is realized, three times the range of most 802.11 products. The SNAPs enjoy the same benefits of frequency-hopping spread spectrum technology that the WIT2410s do. Namely, the immunity to multipath fading and resistance to jamming that is provided by changing frequency every few milliseconds. Operating in the 2.4GHz ISM band, SNAPs can be used license-free worldwide and are not subject to the congestion in the 900MHz band caused by cordless telephones. The SNAP has two modes of operation, AP and PPP. The default mode is the AP mode. In this mode the SNAP uses a special protocol mode called SDP(SNAP Datagram Protocol). In order to send receive or transmit data from the SNAP, the application software must use this protocol. The user may use the API roam library included with the SNAP to help shorten software development. The SNAP can also be configured as a PPP server. This allows any computer with a remote to connect to the same network as the SNAP. These computers then could access any files on the network and support browser-based applications. 2000 Digital Wireless Corporation 042000 GETTING STARTED The SNAP family of wireless Ethernet modems are easy to install and operate. In most instances, the only installation steps will be setting IP addresses, selecting one modem as the master and connecting the antenna, power and Ethernet cable. Connecting the SNAP Figure 1 identifies the various connectors on the rear of the SNAP2410. Power Connector Synchronizing Signals 10BaseT Ethernet Connector TNC Antenna Connector Figure 1. SNAP Rear Panel Diagram The antenna connector is a TNC type connector. An antenna may be connected directly to this connector. Alternatively, an antenna may be located away from the SNAP using RF cable to connect the SNAP to the antenna. Digital Wireless does not recommend using RF cables longer than 5 feet. If more distance is required between the SNAP and the antenna, high-quality, low-loss RF feed line must be used. The 10BaseT Ethernet connector is the standard RJ-45 connector. The connector is wired to be able to connect directly to an Ethernet hub using a straight-through cable. If it is desired to connect the SNAP directly to a PC without a hub, the SNAP must be connected with a cross-over cable. The synchronizing signals are provided for special applications where multiple master SNAPs are employed in an environment with slave SNAPs that are moving. The synchronizing signals are RS-485 levels and may be connected using an RJ-11 connector. In most instances the synchronizing signals are not required and may be left unconnected. The power connector is a 2-pin DIN type connector. The provided AC adapter provides a 9 volt power level to the SNAP. The SNAP can accept DC voltages ranging between 7VDC and 26VDC if alternative power supplies are to be used. 2000 Digital Wireless Corporation 042000 Power Switch Status Indicators Configuration Port SNAP 2410 2.4 GHz SPREAD SPECTRUM WIRELESS ETHERNET MODEM Figure 2. SNAP2410 Front Panel Diagram The Configuration Port is an RS-232 serial port that may be used to configure the SNAP. This is useful when the default IP address of the SNAP cannot be used with the existing network preventing configuration through a telnet session. See the section Configuring the SNAP for details of using this port. SNAP Status Indicators The PWR indicator on the front panel indicates that power is applied to the SNAP and that the power switch is in the ON position. TXD and RXD are indicators of data activity. They indicate the transmission and reception of data over the Ethernet connection. Note that these LEDs can be active even when the SNAP has no remote radios registered. The COLL indicator is illuminated whenever packets collide on the network segment to which the SEM is connected. As such, this is rough indicator of the level of traffic on the network segment. If this LED is glowing brightly on a continuous basis, the throughput of the SEM may appear to be reduced. The LINK indicator when illuminated indicates a good connection to the Ethernet network. If this LED is not on, it can indicate a cross-wired connection between the SNAP and the network. It may also indicate a faulty cable connection. Configuring the SNAP SNAPs are shipped from the factory with default settings that include a default IP address of 192.168.0.254. The network that the SNAP is connecting to must be compatible with 10BaseT products. The SNAP will not work if the network only supports 100BaseT products. Before connecting a default configured SNAP to an active network, ask the network system administrator to make sure that the default IP number will not cause any 2000 Digital Wireless Corporation 042000 problems on the network and that the SNAP will be recognized by the network. If the default IP address conflicts with a device on the existing network, the SNAP will need to be configured through the serial port. The SNAP can be configured two ways. The first is through the serial port. The settings for the serial port are 38400 baud, 8 data bits, 1 stop bit, and no parity. WinSNAP will automatically find the appropriate serial port and configure the serial port settings for you. The software will inform you of its progress and any problems that arise. After a few seconds the SNAP firmware version is displayed followed by the SNAP> prompt. The second configuration method is through a telnet session. Most telnet programs work with the SNAP. Windows 95/98/NT/2000 have a telnet program that works with the SNAP. If there are no conflicts with the default IP number, initiate a telnet session to the SNAP. A telnet session can be started by clicking on Start->Run if you have Windows 95/98/NT/2000 and the TCP/IP client has been installed. Enter the following information in the dialog box: telnet 192.168.0.254 A telnet window will open up. The first line is the version of the SNAP firmware followed by the prompt: SNAP> To change the IP number of the SNAP, use the ip command. ip{yyy.yyy.yyy.yyy} Where x is the new IP address, and y is the optional netmask number. Store the changed configuration parameters in non-volatile memory with the save command: save The SNAP will report back the time it took to the save the information. Reset the SNAP by typing: reset The SNAP can also be reset by cycling power. Whenever a reset is executed on the SNAP, the telnet session will be lost. It will take the SNAP about 30 seconds to reinitialize after a reset or after cycling power. Note: The save and reset commands must be entered after modifying the default configuration. Failure to do so will result in the factory defaults to be used. 2000 Digital Wireless Corporation 042000 SNAP OPERATION Overview At the most basic level, SNAPs can be thought of as Ethernet-to-serial interface adapters. That is, they take data from a host application over a 10BaseT Ethernet connection, remove the Ethernet header information, format the data for WIT2410 radios and transmit the data to the on-board WIT2410 through a high-speed serial interface. In the other data flow direction, the on-board WIT2410 receives data from a remote WIT2410 device. The SNAP takes this data and provides the necessary Ethernet datagram encapsulation and transmits the datagram to the host application over the connected network. A SNAP can be used standalone, or a group of SNAPs can be connected together through a 10BaseT hub to provide seamless roaming over a larger area. When seamless roaming operation is desired, the SNAPs must be synchronized with each other. This synchronization is accomplished either over the Ethernet network or through a differential Sync signal when time delay devices (such as routers) are between SNAPs. See the section on Synchronization for details. Communication between the host application SNAPs can occur at one of two levels. Provided with the SNAP is a library of C routines that constitute a high level API for workstation-based applications. Alternatively, host applications can communicate with a SNAP using the SNAP Datagram Protocol (SDP). This protocol is described in detail later in this manual. The SNAP has a serial Configuration port in addition to the 10BaseT port. This port allows configuration of the SNAP without having to connect it to a network. The WinSNAP configuration utility provided with the SNAP is used to configure the SNAP through the serial Configuration port. Any configuration of the SNAP can be performed using either the Configuration port or over the network. TCP/IP Addresses Each SNAP must be configured with a unique IP address that is appropriate for the network where the SNAP will be used. The IP address can be set using the ip command through the serial-port interface. The ip command takes one or two parameters. The first parameter specifies the IP address for the SNAP, and the second optional parameter, if present, specifies the netmask for the SNAP. If the second parameter is not used, the netmask is set to the default netmask for the IP address specified. For example, the command: ip 192.168.0.1 will set the SNAP’s IP address to 192.168.0.1 and the netmask will remain 255.255.255.0. 2000 Digital Wireless Corporation 042000 The command: ip 192.168.1.233 255.255.255.192 will set the SNAP’s IP address to 192.168.1.233 and will change the netmask to 255.255.255.192. The ip command without any parameters will display the current setting of the IP address and netmask. The SNAP includes a simple ping command that can be used to test the IP address and routing table settings. The SNAP can also obtain its IP address from a BOOTP server if one is present in the network. The BOOTP server will require the Ethernet hardware MAC address to be able to assign the IP address to the SNAP. The Ethernet hardwate MAC address of the SNAP is configured as 00:30:66:XX:YY:ZZ, where XX:YY:ZZ is the unique ID of the SNAP’s “radio A”. The route command can be used to modify and display the IP routing table entries. To display the routing table, use the route list command. There will always be one entry in the routing table that corresponds to the IP address of the SNAP. For most applications, if any routing table entries are required, it will be sufficient to set a default route. To set the default route, use the command: route add default where is the IP address of the default gateway (usually a router or routing host). To remove the default route, use the command “route del default”. To add a route to a particular network or host, use the command “route add [ ]”, where “ ” is the destination network or host IP address, “ ” is the IP address of the gateway, and the optional “ ” is the netmask which defines the destination network. Seamless Roaming The SNAP2410 allows remote radios to seamlessly roam between multiple SNAP2410. The remote radios can also be configured not to roam if this is the required operating condition. In order for the remote to be able to roam seamless the parameter must be set to 2. When the RSSI (receive signal strength indictor) of the remote reaches a certain threshold, the remote will start looking for another SNAP with a higher RSSI. The SNAP will be notified with a CONNECT and DISCONNECT packet when a remote leaves or connects with a SNAP. To facilitate seamless roaming among a group of SNAPs, the SNAPs use Ethernet packets to synchronize time relative to each other. A single “master” SNAP will broadcast (or multicast) special UDP datagrams to the “slave” SNAPs to deliver timing information through the network. The SNAPs can also synchronize with one another by RJ-11 cable (telephone cable). The RJ-11 method of synchronization uses a daisy chain fashion to connect the SNAPs together. The SNAPs need to be synchronized this way if 2000 Digital Wireless Corporation 042000 the ethernet packets can not be transmitted in a timely manner, such as going through a router. Synchronization The SNAP uses broadcast or multicast datagrams for time synchronization. The default is for the master SNAP to broadcast datagrams to the 255.255.255.255 all-hosts IP broadcast address. Using the “sys xcast ”, SNAPs can be configured to use a more limited IP broadcast address, or a multicast address. All SNAPs in a network should be configured with the same “xcast” address. The use of multicast addresses is preferred so that synchronization datagrams do not interfere with hosts other than the SNAPs. Note that the SNAPs use UDP port 2410 as the source and destination UDP port numbers in the synchronization packets. The command “sync master” is used to set a SNAP to the master for time synchronization, and the command “sync slave” is used to set a SNAP to be a slave for time synchronization. There should be one master in a given network, even if there is only one SNAP in the network. There may be a time when there will be SNAP on different sides of a network router. This situation could cause the SNAPs not to be synchronized. This is where the RJ-11 sync connectors can be used. If the remotes will need to be able to roam between the SNAP located on different sides of the network router, the SNAP will have to be connected together using the RJ-11 connectors. The cable will only need to be two twisted pair. This is the same as regular phone cable. If there are more than two SNAPs in the network, the SNAPs will need to be daisy chained together. AP Mode Operation The default operating mode of the SNAP is AP mode. This mode is optimized for communications between a workstation or workstations on an Ethernet network and a network of WIT2410-based devices. The AP mode assumes that there is limited intelligence in the remote host. The AP mode is designed to allow the remote host devices to send and receive data to the remote WIT2410 in transparent mode. Data exchanges between the SNAP and workstations on the network are made using the SDP protocol. This protocol is described in detail later on in this manual. To shorten software development time, a C library is included that will help with the SNAP protocol. roamlib will help in the developing the software needed to talk to the remote radios from the SNAP. Also included is a simple multi-window (one per remote) ethernet chat program, roam.exe. This program allows the user to send data to the SNAP and to the remote. This program is based on the roamlib. In order for roam.exe to work the “sys xcast” must be 224.5.5.5, the “sdp” must be 224.1.2.3 and the source and destination port numbers must be 2411 and 2412 respectively. These are the default settings. Using the roam library requires the use of winsock.dll. This file should already be included on any Windows 95/98/NT PC that has TCP/IP installed as a protocol. 2000 Digital Wireless Corporation 042000 PPP Operation The SNAP can be configured to operate as a PPP (Point-Point Protocol) server. PPP is a dial-in network connection that allows TCP/IP communication. A PPP connection allows a remote connected to a computer to be connected to network that the SNAP is on using the TCP/IP protocol. In order to operate the SNAP as a PPP server, the following sequence of commands must be entered. sys mode PPP save reset The SNAP will also allow the user to specify the starting IP address for the remotes that logon. The first remote to logon will receive the IP address specified below. The SNAP will then add one to the IP address for the next remote to login. ppp base Included in the appendix is a listing of a Windows modem definition file. This inf file will work on Windows 95/98/2000/NT for a remote WIT2410 modem device connected to a serial port. The WIT2410-based modem device needs to be added as a new modem using the standard Windows procedures. When installed, Windows dial-up networking can be used to create a PPP session between the remote PC and the SNAP. The PPP mode of the SNAP also works with various versions of UNIX and LINUX. Contact Digital Wireless Technical Support for details. 4-Port Hub The SNAP2414 model includes a built-in 4-port hub. Even though there are 5 ethernet ports, only four of them can be used. There is an uplink port that can be used to connect to another SNAP or hub. This uplink port is connected to the 4th ethernet port. The hub will not work correctly if a connection is made to both of these ports. This hub will only support 10BaseT networks. 2000 Digital Wireless Corporation 042000 SNAP COMMAND SET The SNAP supports a series of commands that allow for configuring the Ethernet interface as well as the radio parameters of the on-board WIT2410. These commands can be entered during a telnet session or by using the WinSNAP24 utility when the SNAP> prompt is displayed. The commands are summarized here with detailed explanations following. SNAP System Commands Command echo help reset save sys [help mode [AP|PPP] outmax <1-212> xcast [ ] version Description Toggles user screen echo mode Displays command help screen Resets the SNAP activating changed configuration parameters Stores current configuration to memory Displays help screen for command Sets SNAP to Access Point or PPP server mode Set maximum transmit packet length Shows broadcast/multicast address Sets broadcast/multicast address Diplays SNAP firmware version echo Toggles the user screen mode to echo characters typed by the user. Default is on. If echo is turned off, characters typed will not be displayed on the screen unless echoed by the terminal program. help Displays a list of all the SNAP commands. Most commands that require a parameter also have a help mode that displays the help screen for that command. reset Resets the SNAP and loads saved parameters into active memory. Also causes the SNAP to reinitialize which can take 30 seconds. If reset is issued before the save command, the new parameters are lost and the last saved parameters are used. save Saves changed parameters in non-volatile memory to be loaded on power up. Must be issued before the reset command or cycling power to have changed parameters take effect. (An exception is the sys outmax command which becomes active immediately after it is entered.) sys These commands modify system operation parameters. The mode subcommand is used to select the AP or PPP mode of operation. outmax sets the length in bytes of the packets the processor in the SNAP will send to the internal radio. This value cannot be longer than the pktlen value set in the radio. Refer to the section on radio commands for details of the Set Base Slot 2000 Digital Wireless Corporation 042000 Size command. The xcast subcommand is used to set the multicast address to be used when the SNAP puts data out on the network. version Displays the SNAP firmware version. Ethernet Commands Command arp –a -d -s ip [ ] password ping route [ help add del list socks Description Displays arp table Deletes arp entry Adds arp entry Displays current SNAP IP address Sets SNAP IP address and optionally the netmask Sets password for telnet sessions Pings TCP/IP host Displays help screen for command Adds IP address and netmask to route list Deletes IP address from route list Lists route IP addresses Displays network socket information arp Manipulates the address resolution procedure table. This command is provided primarily as a debugging tool for setting up networks. ipaddr is the device IP address and eaddr is the physical Ethernet address of the device ip Sets the IP address of the SNAP. The default IP address is 192.168.0.254. When specified netmask sets the netmask number. The default netmask is 255.255.255.0. password Allows a password to be set to restrict the ability to initiate telnet sessions with the SNAP. When this command is entered, the user is prompted for a new password which is then prompted for a second time for verification. If this password is forgotten, a new password must be entered through the configuration port. ping sends inquiry packets to TCP/IP host specified in and displays the amount of time that elapsed before a response was received. Continuously sends requests until a key is pressed. route Displays and manipulates gateway IP addresses to route IP traffic off the subnet. Default sets the default gateway IP address. When an IP address is entered instead of default, the gateway IP address specified will be used only for traffic destined for that IP address. The route table always has an entry associated with the IP address assigned to the SNAP. socks Displays the network socket information. 2000 Digital Wireless Corporation 10 042000 SNAP Radio Commands Command hop [help length sequence [75|25] radio [A|B] [ help banner network cfg] remote [ help list send ] sync [help ether master override settings slave wire] Description Displays help screen for command Informs SNAP of radio hop dwell time Informs SNAP of number of frequencies in radio hop pattern Displays help screen for command Displays the banner of the specified radio Displays the network number (wn) of specified radio Enters radio command mode Displays help screen for command Displays remotes currently registered with the SNAP Sends data to the remote specified by the handle Displays help screen for command Sets synchronization mode to use Ethernet packets Sets SNAP as synch master Toggles master backup override Displays synchronization settings Sets SNAP as synch slave Sets synchronization mode to use RS-485 wire ports hop Used to inform the SNAP of the hop dwell time or the number of frequencies in the hop pattern of the radio in the SNAP. The parameter entered for length is in 625µs increments. The hop time specified by length should agree with the time specified by the ph parameter in the radio. ph is the hexadecimal value of the number of 69.4 µsec ticks in the dwell time. Thus for each increment in length, the ph parameter should be increased by 9. A value of 16D corresponds to a hop dwell time of 10 msec and is the default. The sequence is the number of hop frequencies in the hop pattern in the radio in the SNAP. The default is 75 for US/ETSI operation. All other frequency bands, as set in the radio by the pe command, have 25 frequencies in their hop patterns. This value is entered as a decimal number. Neither the length nor the sequence need to be modified unless they are modified in the radio in the SNAP. radio Displays information about the configuration of the radio in the SNAP or puts the radio in configuration mode. A or B must be specified to identify to which of the two possible radios in the SNAP the command is directed. The banner command returns the firmware version number and the serial number of the radio in the SNAP. When cfg is entered, the specified radio is put into configuration mode. The SNAP> is replaced with just a > prompt. At this point radio configuration commands may be entered. Refer to the section on radio commands in this manual for the radio commands pertaining to the SNAP. Refer to the WIT2410 Integration Guide for a complete listing of radio commands. 2000 Digital Wireless Corporation 11 042000 remote This command lists the currently registered remotes by the serial number of the remote radio and the assigned handle. The send subcommand will send the specified data to the remote with handle specified in the command. This is intended as a debugging mode and not an operational mode. sync These commands set the operation of the synchronization signal used in multi-SNAP networks implementing seamless roaming. ether and wire are mutually exclusive commands and set the synchronization to occur over the Ethernet or over the RS-485 signal lines. One SNAP must be configured as the sync master and all others must be configured as sync slaves. override toggles the master backup override on and off. AP Mode Commands These commands are unique to the AP mode of operation. Each command is preceded by sdp. Command sdp help add cache delete list max Description Displays help screen for command Add an SDP entry Set number of cached SDP output packets Delete an SDP entry List SDP entries Set SDP maximum packet size help Lists the various commands available under the sdp top level command. add Defines the IP address and port numbers that the SNAP will use when sending and receiving SDP messages. A maximum of 4 SDP entries may be set up. They can be either unicast or multicast addresses. cache Allows the number of datagrams cached by the SNAP to be modified. Cached datatgrams may be requested to be retransmitted by workstations. delete Removes an SDP entry. list List SDP entries and their associated IP addresses and port numbers. max Sets the maximum number of bytes of data that will be included in a SDP datagram before the datagram is sent. If 20ms elapses since the last byte received, the datagram will be sent regardless of the number of bytes in the datagram. 2000 Digital Wireless Corporation 12 042000 PPP Mode Commands These commands are unique to the PPP mode. They are preceded by ppp. Command Description ppp help Displays help screen for command acct method Displays accounting method currently in use Sets accounting method to local or Radius Displays authentication method currently in use Set authentication method to local or Radius Sets base IP address for SNAP [local|radius] auth method [local|radius] base count <1-62> radius help add [auth|acct] [port] delete [auth|acct] port [auth|acct] secret [auth|acct] settings status Displays PPP base allocation count Set to max number of remotes parameter of radio Displays help screen for command Adds IP address of Radius server for authentication or accounting Deletes IP address of Radius server Sets the port number for a Radius server Sets the secret for a Radius server Displays Radius servers settings Displays status of registered users timeout
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