Avaya Definity SI, Maintenance Manual, Page: 2660 / 2968

Maintenance Object Repair Procedures
555-233-123 10-1874 Issue 4 May 2002
Blue Alarm Inquiry Test (#139)
The Blue Alarm is a signal sent by the remote DS1 endpoint when it is
out-of-service. The Blue Alarm Inquiry Test checks the blue alarm status of the
remote DS1 endpoint.
When the UDS1 Interface circuit pack detects a Blue Alarm signal from the
remote DS1 endpoint, the circuit pack transmits a Yellow alarm to the remote DS1
endpoint and sends a BLUE ALARM message to the maintenance software.
When the Blue alarm is confirmed, the maintenance software places all trunks or
ports of the UDS1 Interface circuit pack into the out-of-service state. The inquiry
test runs every 10 minutes until the Blue alarm is cleared.
The UDS1 Interface circuit pack takes one second to recognize and report a Blue
alarm and 16 seconds to recognize and report the resolution of a Blue alarm.
When the Blue alarm is cleared, the UDS1 Interface circuit pack stops transmitting
the Yellow alarm and places the trunks or ports back into the service state before
the Blue alarm occurs.
Line Loopback Alarm
The Line Loopback (LLB) is used by the remote DS1 endpoint to put the ICSU or
DS1 board into a loopback mode. When the ICSU or DS1 board is in the LLB
mode, the arriving bit pattern is regenerated and sent back. The Line Loopback
(LLB) Alarm activates when the in-band activate LLB bit pattern arrives
continuously for 5 seconds on the DS1 line. The LLB deactivates when the
in-band deactivate LLB bit pattern arrives continuously for 5 seconds on the DS1
line.
Since LLB is a maintenance condition rendering all DS0 channels unavailable for
signaling or bearer traffic, maintenance software treats this the same as a Blue
Alarm.
Payload Loopback Alarm
The Payload Loopback (PLB) is used by the remote DS1 endpoint to put the
switch DS1 into a loopback mode. The PLB Alarm activates when a network
protocol activate bit pattern arrives over the 4Kbps ESF data link on the DS1 line.
The PLB deactivates when a network protocol deactivate bit pattern arrives over
the 4Kbps ESF data link on the DS1 line.
Since PLB is a maintenance condition rendering all DS0 channels unavailable for
signaling or bearer traffic, maintenance software treats this the same as a Blue
Alarm