Avaya DEFINITY Server CSI Maintenance Manual page 1786

Maintenance Objects
Loss of Signal Alarm Inquiry Test (#138)
This test verifies the synchronization status, echo cancellation, and continuity of
the DS1 link. The Loss of Signal alarm indicates that the UDS1 Interface circuit
pack is unable to derive the synchronization clock from the DS1 facility. When the
UDS1 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, maintenance software places all
trunks or ports of the UDS1 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 UDS1 Interface circuit pack raises a Loss of Signal alarm after the signal has
been lost for about 1 second. It will not retire the alarm until the signal has
returned for about 10 seconds.
120A1 CSU Module/Sync Splitter
This test is also used to maintain the 120A1 CSU Module or the 401A T1 Sync
Splitter, and the 402A or 403A E1 Synchronization Splitter. The CSU Module,
when combined with the functionality provided by the UDS1 circuit pack, provides
functionality equivalent to an external stand-alone ESF T1 CSU. The combination
of the UDS1 and 120A1 CSU Module is known as an Enhanced Integrated CSU
(I-CSU).
The 401A T1 Synchronization Splitter, when combined with the functionality
provided by the UDS1 circuit pack, allows an ATM switch to derive its timing from
a T1 connected to the UDS1 in the Avaya DEFINITY Server.
The 402A or 403A E1 Synchronization Splitter, when combined with the
functionality provided by the UDS1 circuit pack, allows an ATM switch to derive its
timing from an E1 connected to the UDS1 in the Avaya DEFINITY Server.
If a UDS1 circuit pack detects certain I-CSU/Sync Splitter hardware errors, it
notifies maintenance. When the maintenance subsystem receives notification of
the I-CSU/Sync Splitter error, it executes this Loss of Signal Alarm Inquiry, Test
#138. The test, in addition to querying for a Loss Of Signal alarm condition, also
queries the UDS1 board to confirm the I-CSU/Sync Splitter error. A Minor or
Warning alarm is raised depending on the severity of the I-CSU/Sync Splitter
error. The trunks on the board may be taken out of service if the I-CSU/Sync
Splitter error is deemed serious.
If a Loss Of Signal alarm and an I-CSU/Sync Splitter error co-exist, the Loss Of
Signal alarm condition takes priority, and the board and all trunks on the board are
put in the out-of-service state. Errors are logged, however, for both.
When the maintenance subsystem receives notification that the I-CSU/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 I-CSU/Sync Splitter errors or Loss Of Signal alarm exist).
1786
Issue 5 October 2002