Table Of Contents
1- and 2-Port V.90 Modem WICs for Cisco 2600 and Cisco 3600 Series Multiservice Platforms
The 1- and 2-port V.90 modem WAN interface cards (WICs) for Cisco 2600 and 3600 series multiservice platforms provide low-density integrated modems to satisfy the market demand for remote management, dial-backup, and low-density remote-access servers (RAS).
This document describes the 1-port and 2-port V.90 modem WIC feature and contains the following sections:
Three applications are available for the V.90 modem WIC on the Cisco 2600 and Cisco 3600 series multiservice platforms:
Remote Router Management and Out-of-Band Access
In this mode, the modem WIC is used as a dial-in modem for remote terminal access to the router's command-line interface (CLI) for configuration, troubleshooting, and monitoring. The modem WIC acts similar to a modem that is connected to the AUX port of a router, but the integrated nature of the modem WIC greatly decreases customer configuration time and deployment and sustaining costs. Typically, the 1-port modem WIC is used for this application. Connection speeds of up to 33.6 kbps are possible.
Asynchronous Dial-on-Demand Routing and Dial-Backup
In this mode, the V.90 modem WIC transports network traffic. When ISDN service is not available and the traffic load does not justify a leased-line or Frame Relay connection, asynchronous dial-on-demand routing (DDR) is often the only choice for making a WAN connection. Even at sites that do have leased-line or Frame Relay connection, asynchronous DDR can increase bandwidth during sustained traffic load. In addition, when the primary leased-line or Frame Relay link is down during an outage, asynchronous dial-backup provides a secondary way to make the WAN connection. Both the 1-port and 2-port versions of the V.90 modem WIC can be used for this application.
For more information on Asynchronous Dial-on-Demand Routing and Dial-Backup, please see the document, Configuring Dial Backup for Serial Lines:
Two ports on one modem WIC (or even three or more ports spanning multiple modem WIC cards) can be combined using Multilink PPP (MLP) to increase connection speeds in a scalar manner. Each connection is capable of V.90 speeds (up to 56 kbps) when connecting to a digital V.90 server modem.
For more information on MLP, please see the document, Multilink PPP for DDR—Basic Configuration and Verification:
Low-Density Analog RAS Access
In this application, the V.90 modem WIC enables the platform to provide the services of a typical small remote access server (RAS). One service allows remote users to dial in and gain access to resources on the LAN (or even across the WAN). The analog modems in the modem WIC allow dial-in connection speeds of up to 33.6 kbps, but MLP can bind multiple links together and increase the throughput.
Another service allows PCs (running Cisco DialOut Utility) on the LAN to use the modems for dial-out. Users can connect to other modems (bulletin boards, AOL, ISPs, and so on) or fax machines. The modem WIC allows dial-out connection speeds of up to 56 kbps when dialing a digital V.90 server modem or up to 33.6 kbps when dialing another analog modem. Fax calls connect at up to 14.4 kbps.
Typical RAS deployments with the V.90 modem WIC use the 2-port modem version. With enough slots, the V.90 modem WIC can be used to scale to up to 24 modems in a Cisco 3660 multiservice platform.
There is no limit for lines in the MLP bundle with WICs and population of WICs on any Cisco 2600 series or Cisco 3600 series multiservices platforms.
The 1-port and 2-port V.90 modem WIC feature provides the following benefits:
•Integrated solution for ease of deployment
•Improved remote management
•Cost-effective alternative to leased lines or ISDN
Platform Memory Requirements
•Cisco 2600 ip —8M Flash, 32M DRAMM.
•Cisco 3620 ip plus—16M Flash, 48M DRAMM.
•Cisco 3620 enterprise—16M Flash, 64M DRAMM.
•Cisco 3640 ip plus—16M Flash, 64M DRAMM.
•Cisco 3640 enterprise—16M Flash, 64M DRAMM.
•Cisco 3660 ip plus—16M Flash and 64M DRAMM.
•Cisco 3660 enterprise—16M Flash and 64M DRAMM.
Caution Ensure that the RJ-11/CA11 telephone cable is disconnected from the modem WIC before installing or removing the modem WIC from the router. The phone jack can have DC potential (up to 56.5 VDC) and can have ring signal (up to 150 VAC) in the United States.
Caution Ensure that the router is powered OFF before installing or removing the modem WIC from the router. The modem WICs do not support online insertion and removal (hot-swap).
Other than some currently unsupported commands, the V.90 modem WIC supports all commands available for modem WICs as described in the Cisco IOS Wide Area Networking Configuration Guide and the Cisco WAN Interface Cards Installation and Configuration Guide. For troubleshooting and verification, use only the following commands:
clear modem [counters][ slot/modem # | group group # | all ]
show modem slot/modem#
Related Features and Technologies
For general and specific information on wide-area networking, see the following documents:
•Cisco IOS Wide-Area Networking Configuration Guide, Release 12.1 http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/wan_c/index.htm
•Cisco IOS Wide-Area Networking Command Reference, Release 12.1 http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/wan_r/index.htm
•WAN Interface Cards Hardware Installation Guide http://www.cisco.com/univercd/cc/td/doc/product/access/acs_mod/cis3600/wan_mod/index.htm
•Modem-Router Connection Guide
•Cisco 3600-Series Router Configurations
•Cisco IOS Dial Services Quick Configuration Guide
The following Cisco multiservice platforms are supported for the Cisco IOS Release 12.2(2)XB:
•Cisco 2600 series
•Cisco 3600 series
Supported Standards, MIBs, and RFCs
No new or modified standards are supported by this feature.
No new or modified MIBs are supported by this feature.
To obtain lists of MIBs supported by platform and Cisco IOS release and to download MIB modules, go to the Cisco MIB web site on Cisco Connection Online (CCO) at http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml.
No new or modified RFCs are supported by this feature.
Configuration tasks required for setting up the modem WIC for proper operation are:
Asynchronous Interface Configuration
To configure the asynchronous interface on the V.90 modem WIC, use the following commands, starting in global configuration mode:
Example:Router(config)# interface asyn 33Router(config-if)# ip unnumbered f0/0Router(config-if)# encapsulation pppRouter(config-if)# dialer in-bandRouter(config-if)# dialer string 14085551234Router(config-if)# dialer-group 1Router(config-if)# asyn mode interactiveRouter(config-if)# peer default ip address pool pool123
Note pool123 is a name chosen for the pool used for defining the range of IP addresses for remote clients.
To configure the line on the V.90 modem WIC, use the following commands, starting in global configuration mode:
Example:Router(config-if)# line 33Router(config-line)# modem inoutRouter(config-line)# autoselect pppRouter(config-line)# transport input all
Alternative Configurations for the Modem WIC
Configuring the Group Asynchronous Interfaceinterface Group-Async1ip address negotiatedno ip directed-broadcastencapsulation pppdialer in-banddialer idle-timeout 512 eitherdialer-group 1async default routingasync mode dedicatedno peer default ip addressno fair-queueno cdp enableppp authentication chapgroup-range 33 34hold-queue 10 in
Configuring the Dialer Listdialer-list 1 protocol ip permit
Configuring the Lineline 97 112exec-timeout 0 0autoselect pppscript dialer diallogin localmodem InOuttransport input allstopbits 1flowcontrol hardware
Configuring the Dialer Interfaceinterface Dialer1ip address 22.214.171.124 255.255.255.0no ip redirectsno ip directed-broadcastno ip proxy-arpencapsulation pppload-interval 30dialer remote-name d1dialer pool 1dialer idle-timeout 7200 eitherdialer-group 1no fair-queuepulse-time 0no cdp enable
Configuring for Asynchronous Dial Backup
The following example shows an asynchronous dial backup configuration:interface Serial2/0ip address 126.96.36.199 255.255.255.0backup delay 15 15backup interface as33interface Async33ip address 188.8.131.52 255.255.255.0encapsulation pppdialer in-banddialer map ip 184.108.40.206 name m1_2621_33 modem-script cisco-default 101dialer-group 1ppp authentication chapasync mode interactive!router eigrp 100redistribute staticnetwork 10.0.0.0network 220.127.116.11!ip route 10.0.0.0 255.0.0.0 18.104.22.168 180!/very important/line 33autoselect pppmodem InOutflowcontrol hardwaretransport input all
In this example, the interface S2/0 is configured as a primary link. Configuring the route through the backup interface (the V.90 modem WIC in this case) is very important. 10.0.0.0 in the IP route indicates the network number of the remote end. Thus, all packets for the destination IP are routed through the backup link if the primary link goes down. The 180 in the route command indicates the cost of the route taken (It should be more than the cost of the primary route). This avoids the packets taking the backup link when the primary link is up.
Verifying the V.90 Modem WIC Configuration
Shown below are a few of the many commands that can be used to verify, monitor, and troubleshoot the V.90 modem WIC. Other commands are described in the Related Documents.
The show interface async [tty-number] command shows the state of the specified asynchronous interface.
Example:3640-Router# show interfaces asynch 1Async 1 is up, line protocol is upHardware is Conexant modemInternet address is 22.214.171.124, subnet mask is 255.0.0.0MTU 1500 bytes, BW 9 Kbit, DLY 100000 usec, rely 255/255, load 56/255Encapsulation ppp, keepalive set (0 sec)Last input 0:00:03, output 0:00:03, output hang neverLast clearing of "show interface" counters neverOutput queue 0/3, 2 drops; input queue 0/0, 0 dropsFive minute input rate 0 bits/sec, 1 packets/secFive minute output rate 2000 bits/sec, 1 packets/sec273 packets input, 13925 bytes, 0 no bufferReceived 0 broadcasts, 0 runts, 0 giants0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort221 packets output, 41376 bytes, 0 underruns0 output errors, 0 collisions, 0 interface resets, 0 restarts0 carrier transitions
The show modem [slot/port | group number] command shows various performance statistics for a modem or group of modems.
Example:3640-Router# show modem 1/0Mdm Typ Status Tx/Rx G Duration TX RX RTS CTS DSR DCD DTR1/0 V34 Idle 33600 /33600 0 00:02:41 - - x x - xModem 1/0 [line 33], Async33, TTY33SCM firmware P2109-V90Modem config:Incoming and OutgoingProtocol:LAPM, Compression:V42BLast clearing of "show modem" counters:00:24:522 incoming complete0 incoming failures0 outgoing complete1 outgoing failureModulation type V34# of connections 1Protocol type LAPM# of connections 1Transmit Speed Counters:Connection Speeds 33600# of connections 1Receive Speed Counters:Connection Speeds 33600# of connections 1
Troubleshooting the V.90 Modem WIC Operation
To aid in troubleshooting the V.90 modem WIC operation, use the debug modem command, as shown in the following example:
[no] debug modem
This command shows the state of the tty lines.
Example:00:05:04:TTY1:dropping DTR, hanging up00:05:04:TTY1:Async Int reset:Dropping DTR00:05:04:tty1:Modem:HANGUP->(unknown)cpm_modem_interrupt_handler00:05:05:TTY1:cleanup pending. Delaying DTR00:05:05:TTY1:cleanup pending. Delaying DTR00:05:06:TTY1:cleanup pending. Delaying DTR00:05:06:TTY1:cleanup pending. Delaying DTR00:05:06:%LINK-5-CHANGED:Interface Async1, changed state to reset00:05:07:TTY1:cleanup pending. Delaying DTR00:05:07:TTY1:cleanup pending. Delaying DTR00:05:07:%LINEPROTO-5-UPDOWN:Line protocol on Interface Async1,changed state to down00:05:08:TTY1:cleanup pending. Delaying DTR00:05:08:TTY1:cleanup pending. Delaying DTR
There are no new commands for the V.90 modem WIC feature. All commands used with this feature are documented in the Cisco IOS Release 12.1 command reference publications. See the Related Documents section for more information.
baud rate—bits per second data rate of an asynchronous interface.
DDR—dial-on-demand routing. Also known as direct data routing or dial-up routing (PPP or IP).
DRAMM—Dynamic Random Access Memory Module.
DS0—A single 64 kbps channel of a T1 span.
DSP—digital signal processor.
DSPM—digital signal processing module—voice module card.
IOS—Internet Operating System.
ISDN—Integrated Services Digital Network.
MAR—modular access router.
OIR—Online insertion and removal (hot swap).
POTS—Plain old telephone service.
PSTN—Public Switched Telephone Network.
RAS—remote access server.
TDM—time-division multiplexing. Also used to describe a single channel on a TDM bus.
VFC—voice feature card.
VIC—voice interface card.
WIC—WAN interface card.
Note For a list of other internetworking terms, see the Internetworking Terms and Acronyms document available on the Documentation CD-ROM and Cisco Connection Online (CCO) at the following URL: http://www.cisco.com/univercd/cc/td/doc/cisintwk/ita/index.htm.