Avaya DEFINITY Server CSI Maintenance Manual page 1087

DS1-BD (DS1 Interface Circuit Pack)
Loss of Signal Alarm Inquiry Test (#138)
This test verifies the synchronization status and continuity of the DS1 link. The
Loss of Signal alarm indicates that the DS1 Interface circuit pack is unable to
derive the synchronization clock from the DS1 facility. When the DS1 Interface
circuit pack detects a Loss of Signal alarm, it stops providing the synchronization
clock for the system if it is administered as a timing source and transmits a Yellow
alarm to the remote DS1 endpoint.
When the Loss of Signal alarm is confirmed, the maintenance software places all
trunks or ports of the DS1 Interface circuit pack into the out-of-service state. The
inquiry test will run every 10 minutes until the loss of signal has been restored.
The DS1 Interface circuit pack raises a Loss of Signal alarm after the signal has
been lost for about 1second. It will not retire the alarm until the signal has returned
for about 10 seconds.
This test is also used to maintain the new 120A CSU Module and the 401A T1
Sync Splitter. The CSU Module, when combined with the functionality provided by
the TN767E circuit pack, provides functionality equivalent to an external
standalone ESF T1 CSU. The 401A T1 Sync Splitter, when combined with the
functionality provided by the TN767E circuit pack, allows an ATM switch to derive
its timing from a T1 connected to the DS1 in the Avaya Definity Server CSI.
If a TN767E circuit pack detects certain I-CSU/T1 Sync Splitter hardware errors, it
will notify maintenance. When the maintenance subsystem receives notification of
the error, it will execute this Loss of Signal Inquiry test. The test, in addition to
querying for a Loss Of Signal alarm condition, will also query the TN767E board to
confirm the error. A Minor or Warning alarm will be raised depending on the
severity of the error. The trunks on the board may be taken out of service if the
error is deemed serious.
If a Loss Of Signal alarm and an I-CSU/T1 Sync Splitter error co-exist, the Loss Of
Signal alarm condition will take priority and the board and all trunks on the board
will be put in the out-of-service state. Errors will be logged, however, for both.
When the maintenance subsystem receives notification that the ICSU/T1 Sync
Splitter hardware error condition no longer exists, maintenance will restore the
board and all trunks to their previous service state if the alarm can be cleared (no
other errors or Loss Of Signal alarm exist).
555-233-119 Issue 5 October 2002
1087