Hardware manual

loopback remote (interface)
IR-148
Cisco IOS Interface Command Reference
For the 2- and 4-wire, 56/64-kbps CSU/DSU module, an active connection is required before a
loopup can be initiated while in switched mode. When transmitting V.54 loopbacks, the remote
device is commanded into loopback using V.54 messages. Failure to loopup or initiate a remote
loopback request could be caused by enabling the no service-module 56k remote-loopback
command.
To show interfaces currently in loopback operation, use the show interfaces loopback EXEC
command.
Examples
The following example configures a remote loopback test:
Router(config)#interface serial 0
Router(config-if)#loopback remote
The following example configures the remote device into full-bandwidth line loopback while
specifying the qrw test pattern over the T1 CSU/DSU module on a Cisco 2524 or Cisco 2525 router:
Router(config)#interface serial 0
Router(config-if)#loopback remote full qrw
Router(config-if)#
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0, changed state to down
%LINK-3-UPDOWN: Interface Serial0, changed state to down
%SERVICE_MODULE-5-LOOPUPREMOTE: Unit 0 - Remote unit placed in loopback
The following example transmits a remote loopback stress pattern over the 4-wire, 56/64-kbps
CSU/DSU module, which tests the stress clocking of the network:
Router(config-if)#loopback remote stress-pattern 1
Router(config-if)#
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1, changed state to down
%LINK-3-UPDOWN: Interface Serial1, changed state to down
%SERVICE_MODULE-5-LOOPUPREMOTE: Unit 1 - Remote unit placed in loopback
Related Commands
You can use the master indexes or search online to find documentation of related commands.
clear service-module
loopback dte
loopback line
service-module 56k remote-loopback
service-module t1 remote-loopback
show service-module