Table Of Contents
1-Port DSU/CSU T1 WIC for the Cisco 1700, Cisco 2600, Cisco 3600, and Cisco 3700 Series Routers
Supported Standards, MIBs, and RFCs
Configuring Short Cable Transmission Attenuation
Verifying Configuration of Short Cable Transmission Attenuation
Enabling Remote Loopback Testing
Verifying Enabling of Remote Loopback Testing
service-module t1 cablelength short
service-module t1 remote-loopback
1-Port DSU/CSU T1 WIC for the Cisco 1700, Cisco 2600, Cisco 3600, and Cisco 3700 Series Routers
Feature History
This feature module describes the 1-port data service unit/channel service unit (DSU/CSU) WAN interface card (WIC) for Cisco 1700, 2600, 3600, and 3700 series routers. It describes the benefits of the new feature, supported platforms, configuration, and related documents, and provides command reference information.
This document includes the following sections:
•Supported Standards, MIBs, and RFCs
Feature Overview
The Cisco WIC-1DSU-T1-V2 is an integrated, managed, T1 or fractional T1 WAN interface card (WIC). It provides nonchannelized data rates of 1 to 24 X 64 kbps or 1 to 24 X 56 kbps and follows ANSI T1.403 and AT&T Publication 62411 standards.
The Cisco WIC-1DSU-T1-V2 interface management features include the following:
•You can remotely configure the interface using Telnet and the Cisco IOS command line interface (CLI).
•For monitoring purposes, the router and DSU/CSU are manageable as a single Simple Network Management Protocol (SNMP) entity, using CiscoWorks or CiscoView. DSU/CSU statistics are accessed from the CLI.
•The SNMP agent supports the standard Management Information Base II (MIB II), Cisco integrated DSU/CSU MIB, and T1 MIB (RFC 1406).
•Loopbacks (including a manual button for a network line loopback) are provided for troubleshooting.
•Transmission attenuation can be tailored to cable length using the CLI.
•Test patterns, alarm counters, and performance reports are accessible using the CLI.
•The module has carrier detect, loopback, and alarm LEDs.
Benefits
This T1 DSU/CSU card works on the Cisco 1700, 2600, and 3600 series platforms, and allows customers to integrate more peripheral network components into the chassis. This is especially valuable to customers who deploy large scale, end-to-end Cisco-based branch networks.
Other benefits of this solution include the following:
•Fewer devices to deploy and manage
•Simplified management of the router
•DSU/CSU as a single entity
•Remote/local configuration, monitoring, and troubleshooting by using the CLI
•Single vendor support
•Enhanced reliability
•Physical space savings
Related Documents
Cisco Interface Card Documentation
•Cisco Interface Card Installation Guide
Cisco 1700 Series Routers Documentation
•Cisco 1720 Router Hardware Installation Guide
•Quick Start Guide, Cisco 1720 Router
•Cisco 1721 Router Hardware Installation Guide
•Quick Start Guide, Cisco 1721 Router
•Cisco 1751 Router Hardware Installation Guide
•Cisco 1760 Router Hardware Installation Guide
•Quick Start Guide, Cisco 1760 Router
Cisco 2600 Series Routers Documentation
•Cisco 2600 Series Hardware Installation Guide
Cisco 3600 Series Routers Documentation
•Cisco 3600 Series Hardware Installation Guide
•Quick Start Guide, Cisco 3631 Router
Cisco 3700 Series Routers Documentation
•Cisco 3700 Series Routers Hardware Installation Guide
•Quick Start Guide, Cisco 3725 Router
•Quick Start Guide, Cisco 3745 Router
Cisco ICS 7750 Documentation
•ICS 7750 Documentation Roadmap
Supported Platforms
This feature is supported on the following platforms:
•Cisco 1700 series routers
•Cisco 2600XM and Cisco 2691 routers
•Cisco 3631 routers
•Cisco 3700 series routers
•Cisco ICS 7750 communications manager
Determining Platform Support Through Cisco Feature Navigator
Cisco IOS software is packaged in feature sets that are supported on specific platforms. To get updated information regarding platform support for this feature, access Cisco Feature Navigator. Cisco Feature Navigator dynamically updates the list of supported platforms as new platform support is added for the feature.
Cisco Feature Navigator is a web-based tool that enables you to determine which Cisco IOS software images support a specific set of features and which features are supported in a specific Cisco IOS image. You can search by feature or release. Under the release section, you can compare releases side by side to display both the features unique to each software release and the features in common.
To access Cisco Feature Navigator, you must have an account on Cisco.com. If you have forgotten or lost your account information, send a blank e-mail to cco-locksmith@cisco.com. An automatic check will verify that your e-mail address is registered with Cisco.com. If the check is successful, account details with a new random password will be e-mailed to you. Qualified users can establish an account on Cisco.com by following the directions found at this URL:
Cisco Feature Navigator is updated regularly when major Cisco IOS software releases and technology releases occur. For the most current information, go to the Cisco Feature Navigator home page at the following URL:
Availability of Cisco IOS Software Images
Platform support for particular Cisco IOS software releases is dependent on the availability of the software images for those platforms. Software images for some platforms may be deferred, delayed, or changed without prior notice. For updated information about platform support and availability of software images for each Cisco IOS software release, refer to the online release notes or, if supported, Cisco Feature Navigator.
Supported Standards, MIBs, and RFCs
Standards
No new or modified standards are supported by this feature.
MIBs
No new or modified MIBs are supported by this feature.
RFCs
No new or modified RFCs are supported by this feature.
Prerequisites
The following are prerequisites to enable the T1 CSU WIC:
•Leased line from your telephone company
•Configuration parameters as specified by your telephone company. For most connections, the following default settings should suffice:
–service-module t1 clock source line
–service-module t1 data-coding normal
–service-module t1 timeslots all speed 64
–service-module t1 framing esf
–service-module t1 lbo none
–service-module t1 linecode b8zs
–no service-module t1 remote-alarm-enable
–no service-module t1 fdl
Note In telephone company initiated loopback tests that use the QRSS test pattern, the WIC-1DSU-T1-V2 must be clocked from the line. Configuring the WIC-1DSU-T1-V2 and the telephone company to use the same clock source will result in errors.
Note To view the current configuration, enter the show service-module serial slot/port command. For further information about these commands and how to change them, refer to the Cisco IOS configuration guides and command references.
Configuration Tasks
See the following sections for configuration tasks for this feature.
•Configuring Short Cable Transmission Attenuation
•Enabling Remote Loopback Testing
Configuring Short Cable Transmission Attenuation
To configure transmission attenuation for short cable lengths (under 660 feet in length), use the following commands beginning in global configuration mode.
Verifying Configuration of Short Cable Transmission Attenuation
To verify the configuration of short cable transmission attenuation, enter the EXEC command show running-config interface serial<slot/port> replacing <slot/port> with the slot and port number of the serial interface. The following sample output shows transmission attenuation for a cable length between 0 and 110 feet:
Router#show running-config interface serial0/0Building configuration...Current configuration : 252 bytes!interface Serial0/0no ip addressload-interval 30no keepaliveno fair-queueservice-module t1 cablelength short 110ftservice-module t1 framing sfservice-module t1 linecode amiservice-module t1 timeslots 1-24 speed 56no cdp enableendEnabling Remote Loopback Testing
To enable remote loopback testing for the WIC, use the following commands beginning in global configuration mode.
Verifying Enabling of Remote Loopback Testing
To verify the loopback status of the current interface, after the far end has been put in loopback mode, enter the command show service-module serial<slot/port> replacing <slot/port> with the slot and port number of the serial interface. The output "Unit is currently in test mode: remote loopback is in progress", as shown in the following example, indicate that remote loopback testing is enabled:
Router#show service-module serial0/0Module type is T1/fractionalHardware revision is 0.1, Software revision is 20021210,Image checksum is 0x81277248, Protocol revision is 0.1Receiver has no alarms.Unit is currently in test mode:remote loopback is in progressFraming is SF, Line Code is AMI, Current clock source is line,Fraction has 24 timeslots (56 Kbits/sec each), Net bandwidth is 1344 Kbits/sec.Last module self-test (done at startup): PassedLast clearing of alarm counters 01:52:27loss of signal : 1, last occurred 01:45:24loss of frame : 2, last occurred 01:45:24AIS alarm : 0,Remote alarm : 0,Module access errors : 0,Total Data (last 7 15 minute intervals):255 Line Code Violations, 0 Path Code Violations1 Slip Secs, 326 Fr Loss Secs, 6 Line Err Secs, 0 Degraded Mins2 Errored Secs, 0 Bursty Err Secs, 7 Severely Err Secs, 327 Unavail SecsData in current interval (445 seconds elapsed):0 Line Code Violations, 0 Path Code Violations0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins0 Errored Secs, 0 Bursty Err Secs, 1 Severely Err Secs, 0 Unavail SecsConfiguration Example
This section provides a configuration example for a Cis co 1751 router with a WIC-1DSU-T1-V2 card installed. It is in a short cable environment (between 330 and 440 feet here), and is set to enter loopback when a loopback code is received on the line.
Current configuration :!version 12.2no parser cacheno service single-slot-reload-enableservice timestamps debug uptimeservice timestamps log uptimeno service password-encryption!hostname 1751-uut1!interface Serial0/0ip address 10.0.0.51 255.0.0.0service-module t1 framing esfservice-module t1 linecode b8zsservice-module t1 timeslots 1-12 speed 64service-module t1 data-coding normalservice-module t1 cablelength short 440ftservice-module t1 remote-loopback full!interface FastEthernet0/0ip address 6.0.0.1 255.0.0.0speed autofull-duplex!ip classlessno ip http server!!line con 0line aux 0line vty 0 4login!endCommand Reference
This section documents new and modified commands. All other commands used with this feature are documented in the Cisco IOS Release 12.2T command reference publications.
New
•service-module t1 cablelength short
Modified
•service-module t1 remote-loopback
service-module t1 cablelength short
To set transmission attenuation for shorter cable lengths, use the service-module t1 cablelength short command in interface configuration mode. To disable, use the no form of this command.
service-module t1 cablelength short {110ft | 220ft | 330ft | 440ft | 550ft | 660ft}
no service-module t1 cablelength short
Syntax Description
Defaults
No default behavior or values.
Command Modes
Interface configuration mode.
Command History
Usage Guidelines
This command is intended only for the Version 2 card, WIC-1-DSU-T1 V2, as part of the service-module t1 configuration options.
Use this command to configure the tx attenuation for cables whose length is shorter than 660ft. The related command, service-module t1 lbo, is used to define the line-build-out values for cablelengths longer than 660ft. At any time, only one, either the short configuration or the lbo configuration, can exist. They cannot co-exist. The configuration of one command will cause the effect of the other command to cease and only the new command will be in effect. The no form of this command will configure the attenuation to the default line-build-out gain of 0 db.
Examples
The following example sets the short cablelength to 220ft.
Router(config)#int s0/0Router(config-if)#service-module t1 cablelength short 220ftRelated Commands
Command Descriptionservice-module t1 lbo
Configures the CSU line-build-out (lbo) on a fractional T1/T1 DSU/CSU module.
service-module t1 remote-loopback
To specify that the fractional T1/T1 DSU/CSU module enters loopback mode when it receives a loopback code on the line, use the service-module t1 remote-loopback interface configuration command. Use the no form of this command to disable remote loopbacks.
service-module t1 remote-loopback {full | payload v54}
no service-module t1 remote-loopback {full | payload v54}
Syntax Description
Note By entering the service-module t1 remote-loopback full command without specifying any keywords, you enable the standard loopup codes, which use a 1-in-5 pattern for loopup and a 1-in-3 pattern for loopdown. By entering the service-module t1 remote-loopback payload v54 command without specifying any keywords, you enable the v54 pseudo-random loopup codes for loopup and v54 pseudo-random loopdown codes for loopdown.
Defaults
Full and payload loopbacks with standard-loopup codes.
Command Modes
Interface configuration mode.
Command History
Release Modification11.2
This command was introduced.
12.2( 15)ZL
The provision for an alternate loopback code was removed.
Usage Guidelines
The no form of this command disables loopback requests. For example, the no service-module t1 remote-loopback full command ignores all full-bandwidth loopback transmissions and requests.
Configuring the no form of the command might not prevent telco line providers from looping your router in esf mode because fractional T1/T1 lines use facilities data link messages to initiate loopbacks.
To have the loopback remote commands on the FT1/T1 CSU/DSU module function successfully, you need to enable the service-module t1 remote-loopback command.
Examples
The following examples display two routers connected back-to-back through a fractional T1/T1 line.
The example for loopback remote full:
Router(config)#int s0/0Router(config-if)#service-module t1 remote-loopback fullRouter(config-if)#loopback remote fullRouter(config-if)#%SERVICE_MODULE-5-LOOPUPREMOTE: Unit Serial0/0 - Remote unit placed in loopbackRouter(config-if)#no loopback remoteRouter(config-if)#%SERVICE_MODULE-5-LOOPDOWNREMOTE: Unit Serial0/0 - Remote loopback test cancelledThe example for loopback remote payload v54:
Router(config)#int s0/0Router(config-if)#service-module t1 remote-loopback payload v54Router(config-if)#loopback remote payloadRouter(config-if)#%SERVICE_MODULE-5-LOOPUPREMOTE: Unit Serial0/0 - Remote unit placed in loopbackRouter(config-if)#no loopback remoteRouter(config-if)#%SERVICE_MODULE-5-LOOPDOWNREMOTE: Unit Serial0/0 - Remote loopback test cancelledRelated Commands
Command Descriptionloopback remote (interface)
Loops packets through a DSU/CSU to a remote DSU/CSU and back, over a channelized T1 link.