Network Device User's Guide

Monitoring and Testing
4-16
3166-A2-GB20-10
November 1998
Remote Loopback Tests
The Remote Loopback tests enable you to troubleshoot your circuit by sending
the following to a far-end device:
For Networks
 Line loopback up activation sequence for 10 seconds (LLBUP)
 Line loopback down activation sequence for 10 seconds (LLBDN)
For Channels
 V.54 activation sequence to initiate a V.54 Loop 2 (54UP)
 V.54 deactivation sequence to terminate a V.54 Loop (54DN)
 ANSI T1.403 (Annex B) activation sequence to initiate a DCLB on the remote
device (FT1UP)
 ANSI T1.403 (Annex B) deactivation sequence to terminate a DCLB on the
remote device (FT1DN)
You cannot perform remote loopbacks if any of the local loopbacks are active. If
you attempt to do so, the error message Invld Test Combo (Invalid Test
Combination) appears.