Problem Description

After a frontline engineer sets up an SSN2PQ1A03 single-board port inner loop on an OSN2500 R8C02 version network element, the loopback is never automatically released, . The loopback was eventually lifted manually. On the other hand, other line veneers can automatically release the loopback after setting it.

Alarm message

:cfg-set-loop:7,1,inloop

51026 7 LOOP_ALM MN start 2011-08-11 20:27:26 None 0x01 0x00 0x01 0x00 0x00 0x00

Process

Manually unlock the tributary single board loopback.

Root Cause

The mainframe has been modified in R7 extreme later versions, and all branch circuit boards in R7 and later mainframe versions do not support unloopback. All line boards support automatic unloopback.

Recommendations and Summary

By command:cfg-set-loop:7,1,inloop

Setting loopback in port one of single board No.7

You can use the following command to query whether the port that is currently in loopback state can be released automatically or not

:cfg-get-autoclearlist.

AUTOCLEAR-RECORD

optype bid port path

portloop 7 1 0

Form output method with corresponding fields:

OPTYPE : Type to be autocleared

BID : Board ID

PORT : Port number

PATH : Channel number

This means that port 1 of board 7 can be automatically released from loopback.