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OTU3_LOF Alarm due to STG Board

Publication Date:  2012-07-25 Views:  163 Downloads:  0

Issue Description

We are adding one additional 8800T32 sub rack at a gateway site.
But after adding the new sub rack we have to confront with the OTU3 LOF alarm on all NS3 present in the new sub rack.
At that time, no screen shots were taken.

Alarm Information


Handling Process

Now, next day on site visit we saw that there is a STG board is present on the Slot 44, but its LED is in OFF condition.

We've reseated the TN52STG board & configured, everything got OK.....all OTU3_LOF alarms present on NS3's got cleared.

Then we're also having a new STG board with us (in case of failure). So we've placed that STG board in Slot 42, which was empty.

Root Cause

There are several causes for OTU3_LOF alarm, but our main concern is that the STG is not showing on NMS view which has to be at the 8800 T32 subrack on slot 42/44.
In meantime, we refered to the Product document, which also shows that :


For 8800 T64 & T32 Subrack with a crossconnect board must have TN52STG board with configuration.