Diagnostic Tests; Bit Error Rate Performance Testing - Nortel DMS-100 Series Maintenance Manual

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Diagnostic tests

Bit error rate performance testing

Bit error rate performance (BERP) tests test transmission paths through the
network. The BERP test allows the operating company to assess the bit error
performance of the Digital Multiplex System-100 (DMS-100) switch and
subtending nodes. The BERP are provided with tests with feature package
NTX881AB. The BERP requires the NT6X99AA IBERT line card supplied
in the LCM of the OPM.
The BERP tests consist of many separate bit error rate tests (BERT). To
perform a BERT test, operating company personnel must transmit a known bit
pattern and connect an integrated bit error rate tester (IBERT) to one of the
following:
•
•
The system reflects this bit pattern back to the IBERT and compares the IBERT
to the item that was sent. The system records any errors in the returned bit
stream. The results of these separate BERTs comprise the result of the BERP
test.
The user can access the BERP test from the maintenance (MTC) level of the
MAP terminal. Commands at the BERP level set up tests all the time or for a
fixed duration.
Link tests
The BERP tests can perform on the DS-1 links that connect the host controller
to the OPM. To perform the BERP test on a DS-1 link, a loopback must be
present at some point on the transmission path. The DS-1 loopback is at the
P-side of the host XPM. The system loops back all 24 channels on the DS-link.
When use of a DS-1 loopback occurs, the removal of the DS-1 link undergoes
necessary tests from service.
Post the OPM.
Use the QUERYPM command to display the PM load that resides in the OPM.
Determine the correct OPM PM load.
Correct Table LCMINV if the table has the wrong PM load for the OPM.
If the table has a PM load that is not correct for the OPM, obtain the correct
PM load. Load the OPM again.
the IBERT
a specified endpoint, like data line card (DLC)
DMS-100 Family OPM Maintenance Manual XPM14 and up
Trouble isolation and correction 10-5