Nortel DMS-100 Series Maintenance Manual page 428

11-2 Advanced troubleshooting procedures
The system records critical events in the SMS with the associated data
during the normal operation of the SMS. When the active buffer is full, the
buffer wraps around to the beginning of the data area. The full active buffer
overwrites data events recorded before. This feature makes sure that the
latest events are present in the footprint area. This wrap can result in the
loss of important data. To avoid loss of data, the system groups events in
classes. The type of events that the footprint tool stores occur in the
following SMS classes:
Select or omit these classes of events to fine tune the data the system
collects. Select or omit these classes of events to make sure the data does
not overflow the buffers. For example, the suspected cause of an outage is a
specified diagnostic. You can enable this class, and omit all other classes to
focus the data collection on the diagnostics.
The system records an additional set of events and system variables before
the SMS unit reinitializes. Before the system reinitializes the SMS unit, the
system decides if the system must lock the active buffer. The following
conditions determine this decision:
A footprint information area is available. This footprint information area
points to a wraparound. The footprint information area indicates the size of
297-8231-550 Standard 09.01 August 1998
Note: The system does not lock the buffers for planned SMS outages
like manual warm activity switches (SWACT) or routine exercise (REX)
tests. The system does not lock the buffers for Busy (BSY) operations.
The system does not lock buffers if a holding buffer is locked.
maintenance
sync
activity
diagnostics
audits
messaging
patcher
call processing
PMDEBUG
static data
If the drop request came from the central control (CC), the system does
not lock. Buffers can lock after a system request.
If an internal SMS decision caused the drop request, the system locks the
buffers.