This is a high level 'smart MIB' object. This object provides a running average of the number of errors per 10000 packets. This is an error rate, and is calculated over the number of packets received in the sample periods, and not on every 10000 packets. This value is calculated locally on the agent and so does not require processor bandwidth from a management station or occupy valuable network bandwidth communicating with that station.

By default an agent supporting this parameter will exhibit the following behaviour:

1) The parameter will be recalculated at approx 15 second intervals. 2) Every calculation period the device will read the value of mrmMonPortTotalErrors and mrmMonPortReadableFrames. 3) The calculation will be performed on the most recent 4 samples as follows:

4 Sum(Errors(i)/Frames(i)) * 10000/4 i=1

Errors(i) = mrmMonPortTotalErrors(i)-mrmMonPortTotalErrors(i-1) Frames(i) = mrmMonPortReadableFrames(i)-mrmMonPortReadableFrames(i-1)

The value is an integer number of errors per 10,000 packets received by this repeater.

A default threshold exists on this average so that if a calculated average exceeds 200 (i.e. 2% of frames are in error) a trap will be sent to the management station. Further traps will not be sent until the average drops to below 100 (i.e. 1% of frames are in error).

A particular device may provide a means of changing the number of samples, the averaging period and threshold if it so wishes.