Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

Re: aRunts

At 06:41 AM 4/28/01 -0700, Jamal Elsaadi wrote:

aRunts, what is this variable means ?

See the definition below taken from Clause 30.
This is an error condition.
In a CSMA/CD network there is a window of event size that "shouldn't happen". That is, the event is longer than a legal collision fragment and smaller than a legal frame. If you are going to try to have all carrier events reported in 10 Gig and use the same buckets that are used at lower speed (so that you can use the same management) then you gotta have it included. aRunts
Generalized nonresettable counter.This counter has a maximum increment rate of 75 000 counts
per second at 10 Mb/s
Increment counter by one for each CarrierEvent that meets one of the following two conditions.
Only one test need be made.
        a)The ActivityDuration is greater than ShortEventMaxTime and less than ValidPacketMinTime and the CollisionEvent signal is deasserted.
        b)The OctetCount is less than 64,the ActivityDuration is greater than ShortEventMaxTime,and the CollisionEvent signal
is deasserted. For 10 and 100 Mb/s repeaters,ValidPacketMinTime is greater than or equal to 552 BT and less than 565 BT.A CarrierEvent greater than or equal to 552 BT but less than 565 BT may or may not be counted as a runt.At 10 Mb/s an event whose length is greater than 74 BT but
less than 82 BT shall increment either the aShortEvents attribute or the aRunts attribute,but not both.ValidPacketMinTime has tolerances included to provide for circuit losses between a
conformance test point at the AUI and the measurement point within the state diagram.
For 1000 Mb/s repeaters,ValidPacketMinTime is 4136 BT.

NOTE: Runts usually indicate collision fragments,a normal network event.
In certain situations associated with large diameter networks a percentage of runts may exceed ValidPacketMinTime.;