Avaya S8700 Maintenance Manual page 406

Maintenance Object Repair Procedure
ISDN Test Call Test (#258)
This test performs a far-end loop around to a far-end switch over an ISDN trunk.
The trunk's service state must be in-service, maint-NE, or out-of-service/NE, and
no call can be active on the trunk.
A test call connection is established to a far-end switch over the ISDN trunk to be
tested. The digital port on a TN711D Maintenance/Test circuit pack generates a
test-pattern bit stream that is sent to the far-end switch and echoed back. The
received pattern is then compared to the sent pattern and checked for errors that
indicate a loss of integrity on the communications path.
If a test call is running when scheduled maintenance starts, the green LED is
turned off. To determine whether a test call is still running:
Issue the list isdn-testcall and status isdn-testcall commands.
Check for a lit amber LED on the Maintenance/Test circuit pack.
There are two ways to place an outgoing test call over trunk-side ISDN-BRI
facility:
1. The test call connection is established over the TDM bus of the transmit
and receive sides of the trunk-side ISDN-BRI facility to a digital trunk
testing port on the Maintenance/Test circuit pack. The Maintenance/Test
Digital Port generates a pseudo bit stream.
2. The test call connection is established over the TDM bus of the transmit
and receive sides of the trunk-side ISDN-BRI facility to a data channel.
This method is selected when no Maintenance/Test circuit pack resides in
the system.
A test is run periodically to check if the call is hung. If so, it gracefully tears down
the call to release the resources.
Synchronous Commands
You can demand a synchronous outgoing test call by using the following
maintenance commands:
test trunk trunk-group-no/member-no long [repeat-number]
test board UUCsspp long [repeat-number]
test port port-location long [repeat-number]
Whenever a circuit translates to a trunk-side ISDN-BRI channel during a long test
sequence, an outgoing test call is invoked, and the duration of the test call is 8.6
seconds. Once the test call completes, the bit error rate is retrieved from the
Maintenance/Test Digital Port. A bit error rate greater than zero is reported as a
failure to the Manager I terminal (MGRI). A failure indicates the need to run
further diagnostics.
8-1102 Issue 1 May 2002 555-233-142