Counters And Rmon Alarms - 3Com LINKBUILDER 3C18500 User Manual

D-8 A D: RMON A M
PPENDIX AND DVANCED ANAGEMENT

Counters and RMON Alarms

The management module supports the RMON alarm. Alarms can be
assigned by Transcend or any SNMP network manager to monitor any
counter. Consult the manual of the application you use for details of
how to set up the possible 1024 alarms.
Each alarm monitors its assigned counter, by calculating the differences
over a preset time interval. It remembers the high and low tide marks
and it can take actions when the value of the counter has crossed
preset thresholds. The diagram below shows the variation of a typical
counter with time.
Figure A-5 Counter Values During Autosetting Of Thresholds
Alarm thresholds may be autocalibrated or set manually.
Autocalibration is a means of calculating alarm thresholds specific to
the activity of the counter being monitored. For autocalibration, the
high threshold is set to 5% above the high tide mark. Also, the low
threshold is set to 20% below the high tide mark (see diagram above).
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