Nortel DMS-100 Series Maintenance Manual page 68

1-52 Maintenance overview
Processor occupancy—memory block reduction after real-time overload
detection
The XLCM is memory block limited and cannot handle real-time overload.
This state can result in outages because of the following
Enhancements to the overload protection system
The enhanced XLCM overload protection system detects when the XLCM is
in real-time overload, reports overload to the CM. The enhanced XLCM
also takes protective measures to assure XLCM sanity. These protective
measures are active for as short a time as possible to retain the XLCMs call
processing capacity.
This enhancement adds three new components to the current Overload
Protection System:
297–8351–550 Standard 04.01 August 1999
Processor occupancy
100%
0%
0
the system does not transmit an overload report because XLCMs do not
currently detect real-time overload. The CM does not suspend functions
that require a response from the XLCM. The CM suspends functions
when the system transmit an overload report. If the XLCM does not
respond in time, the CM system busies the XLCM.
the system cannot handle starvation, when lower priority tasks cannot
run. This problem can lead to traps or important software errors which
cause the CM to system busy the XLCM.
Processor occupancy data collection component is distributed over key
areas of the XLCM code to collect raw data. This data is used to detect
real-time overload. The processor occupancy data collection component
leaves the raw data in a depository for the data analysis component. The
priority of this component matches the priority of the segment of the
system in which the component resides.
P-phone MADN traffic
POTS traffic
Adjusted Normal
max max
Memory blocks