Unusable Communication Links; Loop-Around Message Audit Failure - Nortel DMS-100 Series Maintenance Manual

Unusable communication links

The following conditions do not allow the use of communication links from
the OPAC to the CM:
There is a break in the links between the OPAC and the host.
The peripheral side (P-side) message link (DS-1 cards) of the LTC are
pulled out.
The C-side message link (DS-1 cards) of the OPAC are pulled out.
The RLCM_ESAENTRY_BADLINK office parameter determines the
desired delay time between failure of the C-side message link and enter of
the ESA mode.

Loop-around message audit failure

The OPAC enters ESA mode when the loop-around message audit detects
failure of messaging between the OPAC and the CM. The following
conditions cause this failure:
An extended loss of communication with the CM for longer than the
time-out period the RLCM_ESAENTRY_BADCSIDE office parameter
specifies.
Both LTC units (C-side peripherals) are ManB.
Network planes of the LTC or LGC are ManB.
The RLCM_ESAENTRY_BADCSIDE office parameter determines the
desired delay time between failure of OPAC communication with the C-side
peripheral and entering ESA mode.
The delay time prevents the OPAC from entering the ESA mode while the
system performs a restart. A restart causes the loop-around message to fail.
The OPAC enters ESA mode if all loop-around messages within the time-out
period fail.
DMS-100 Family OPAC Maintenance Manual XPM12 and up
ESA maintenance overview 3-29