3Com 10002211 Switch User Manual


 
RMON Groups B-5
History and
axFDDI Groups
The History group records periodic statistical samples from the network
and stores them for retrieval at another time. The information available
per interface for each time interval includes:
Number of received octets
Number of received packets
Number of received broadcast packets
Number of received multicast packets
Number of received packets with CRC or alignment errors
Number of received undersized but otherwise well-formed packets
Number of received oversized but otherwise well-formed packets
Number of received undersized packets with either a CRC or an alignment
error
Number of detected transmit collisions
Estimate of the mean physical layer network utilization
Alarms
The CoreBuilder 6000 system supports the following syntax for alarms:
Counters
Gauges
Integers
Timeticks
These mechanisms report information about the network to the network
administrator. Counters, for example, hold and update the number of
occurrences of a particular event through a port, module, or switch on the
network. Alarms monitor the counters and report instances of when
counters exceed their set threshold.
Counters are useful when you compare their values at specific time intervals
to determine rates of change. The time intervals can be short or long,
depending on what you measure. Occasionally, reading counters can give
you misleading results.
Counters are not infinite, which makes rate comparisons an efficient way to
use them. When counters reach a predetermined limit, they return to 0 (roll
over). A single low counter value might accurately represent a condition on
the network. Or it might simply indicate that a roll over has occurred.