Nortel DMS-100 Series Maintenance Manual page 88

1-72 Maintenance overview
Pre-gain audit
The pre-gain audit monitors the XPM status data in the inactive unit. The
pre-gain audit sends the XPM status data to the pre-drop audit in the active
unit. The pre-drop audit uses the XPM status data to determine if the active
unit must drop activity. The XPM status data examined by the audit
includes the following:
The pre-gain audit continues to monitor and report unit status and condition
information while the unit is inactive. The pre-drop audit uses the
information provided by the pre-gain audit to determine if the active unit can
drop activity. A Warm SWACT occurs and the post-gain audit in the newly
active unit begins to run.
Post-gain audit
The post-gain audit runs in the newly active unit. The post-gain audit
verifies that the unit establishes two-way communication with the CM. If
the unit establishes communication with the CM, the newly active unit
maintains activity.
If the communication check fails, the unit forces a drop of activity to initiate
a SWACT back to the originally active unit. In this occurrence, the pre-drop
audit does not refuse the SWACT. The pre-drop audit allows the SWACT to
proceed. If the SWACT back fails, the XPM node is busied and returned to
service.
Post-drop audit
The post-drop audit runs in the newly inactive unit. The newly inactive unit
remains in service for a temporary period. The newly inactive unit does not
initialize. The post-drop audit cleans up the call processing data structures
of calls that are not stable and stable calls that are not synchronized. If a
297-8231-550 Standard 09.01 August 1998
Facility audits – the XPM records the result of the last run for each
diagnostic in the facility audit for a given peripheral.
Status information contained within the unit – this information includes
if the inactive unit:
— is in-service and ready
— has CM links OK
— does not have corrupt static data
— is in synchronization
— is not jammed as the inactive unit
Note: An inactive unit cannot reach all diagnostic paths. You may need
to perform a manual SWACT with the FORCE option. This action
clears a failure from the pre-gain audit record.