Avaya S8700 Series, Maintenance Manual

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Maintenance-Object Repair Procedures
555-233-143 8-342 Issue 1 May 2002
This Loop Around test runs a series of individual tests on the two B channels (B1
and B2) associated with the port. It is a collection of the following:
■
Loop Around test across the TDM Bus for B1.
■
Conference Circuit test for B1.
■
Loop Around test across the TDM Bus for B2.
■
Conference Circuit test for B2.
The tests are run in the above order. If one fails, the remaining tests in the
sequence are not executed. An error code is returned at that point.
This test is not executed for ABRI-PORT/ATT-PORT/LGATE-PT/ATTE-PT
because the B channels associated with the port are not used by ASAI or Avaya
adjuncts.
The dotted lines in Figure 8-13 on page 8-342 show how a Loop Around test is
performed for the B channels. The figure shows a terminal connected to a BRI
line board using a TN556. If a TN2198 is used the terminal would be connected to
a NT1, and the NT1 to the BRI board.
Figure 8-13. Path of the BRI Port Local TDM Loop Around
Tone
Generator
Tone
Detector
BRI Line
Board
TDM Bus