Avaya 03-300430 User Manual

The Line Loopback (LLB) is used by the remote DS1 endpoint to put the DS1 board into a 
loopback mode. When the 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.

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

 ABRT

Internal 

system 

error

1. Retry the command at 1-minute intervals for a maximum of 5 times.

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