Configuring A Line Loopback On A Service Module; Managing Bit Error Rate Tests; Configuring A Bit Error Rate Test - Cisco MGX 8850 (PXM1E/PXM45) Configuration Manual

Managing Bit Error Rate Tests

Note

Configuring a Line Loopback on a Service Module

Once your physical line is connected, you can perform a loopback test using the following procedure.
Connect a single line to the appropriate transfer and receive ports on the backcard you want to test.
Step 1
Step 2 Establish a configuration session with the active PXM1E or AXSM using a user name with
SERVICE_GP privileges or higher.
Step 3 Enter the dsplns command to display the configuration for all lines on the current card.
Step 4 Enter the addlnloop <-line type> <bay.line> <-lpb loopback type> command.
addlnloop -ds3 2.1 -lpb 2
Enter the dspln -<line type> <line_num> command to verify the that the appropriate line is in the
Step 5
specified loopback state.
dspln -ds3 4.1
Before you can change the loopback type for an existing loopback, you must first delete the loopback by
executing dellnloop, or you can just enter the addlnloop command with the -lpb 1 (No loopback) option.
Managing Bit Error Rate Tests
BERT commands can help you analyze and resolve problems on a physical interface. To conduct a BERT
on a line, a user sends a specified pattern over a line that is configured in loopback mode at the far end.
The local end receives the loopback pattern, and the user compares the local end pattern to the original
pattern sent from the far end. The number of bit errors discovered in the local (or receive) end pattern
help the user determine the quality of the physical line.
BERT is only available for T1 lines and IMA cards.
Note

Configuring a Bit Error Rate Test

Use the following procedure to configure BERT on an MGX switch.
Step 1 Put the appropriate lines into loopback mode.
Establish a configuration session with the active PXM1E or PXM45 using a user name with
Step 2
SERVICE_GP privileges or higher.
Cisco MGX 8850 (PXM1E/PXM45), Cisco MGX 8950, Cisco MGX 8830, and Cisco MGX 8880 Configuration Guide
9-80
Before you can change the loopback type for an existing loopback, you must first delete the
loopback by executing dellnloop, or you can just enter the addlnloop command with the -lpb 1
(No loopback) option.
Chapter 9 Switch Operating Procedures
Release 5.0.10, OL-3845-01 Rev. B0, August 16, 2004