RE: RUNT Packets
Louis,
Where do you plan to use Runt in 802.3ae?
The existing runt object, aRunts, is a part of the repeater monitoring
performance capability. The MAC has no equivalent counter. The MAC doesn't
run LayerManagementReceiveCounters until it goes through ReceiveDataDecap
with receiveSucceeding. ReceiveSucceeding is only sent when the received
frame was greater than the minimum packet length. Therefore,
LayerManagementReceiveCounters is not run for runts and has no counters for
runts. The MAC managed objects do not currently contain an object for runts.
We counted runts in the repeater to contribute to an understanding of how
busy the network was since they represent time spent in collisions. We
didn't monitor them in the MAC where performance monitored was the more
selfish view of "How often do I experience a collision when I transmit?"
Therefore, runts do not apply to 802.3ae and we don't need to say anything
about them.
Pat
-----Original Message-----
From: Louis Lin [mailto:louislin@xxxxxxxx]
Sent: Wednesday, November 15, 2000 2:17 PM
To: THALER,PAT (A-Roseville,ex1)
Cc: Grow, Bob; 'James Colin'; stds-802-3-hssg@xxxxxxxx
Subject: Re: RUNT Packets
Hi,
Should we say Runt is a carrier event comes to the receive port with
qualified preamble and SFD, and it ends as an undersized packet.
If a carrier event comes to the receive without the valid preamble
and SFD, then it's just a carrier event.
Regards,
Louis
"THALER,PAT (A-Roseville,ex1)" wrote:
> Bob,
>
> I do not understand your point. At lower speeds, there are four possible
> causes of a runt -
>
> A noise hit causes a short event on a segment which arrives at a repeater,
> since ther repeater never transmits less than a minimum size fragment it
> sends a runt.
>
> A collision fragment
>
> A noise hit that causes an end delimiter to be detected in error.
>
> Someone transmitted a frame smaller than the minimum frame size. (Is this
> the protocol error you referred to?)
>
> Therefore, at the lower speeds, runts can be caused by noise, the normal
> operation of CSMA/CD or transmission shorter than the minimum. For full
> duplex they are only caused by noise or transmission shorter than minimum.
>
> Pat
>
> -----Original Message-----
> From: Grow, Bob [mailto:bob.grow@xxxxxxxxx]
> Sent: Tuesday, November 14, 2000 10:52 AM
> To: 'James Colin'; stds-802-3-hssg@xxxxxxxx
> Subject: RE: RUNT Packets
>
> A minimum frame size was established at 10 Mb/s to assure that collisions
> were detected. Shorter "runt" frames are an error and are commonly
counted
> and monitored in management databases. In the desire to maintain
> consistency over all speeds of ethernet, we should attempt to preserve
> similar error properties. If the RS turns an error created by
transmission
> noise into a protocol error (e.g., runt frame) we are violating the
> objective to make things look the same.
>
> --Bob Grow
>
> -----Original Message-----
> From: James Colin [mailto:james_colin_j@xxxxxxxxx]
> Sent: Tuesday, November 14, 2000 2:50 AM
> To: stds-802-3-hssg@xxxxxxxx
> Subject: RUNT Packets
>
> Louis, Bob
> Can you explain the term "runt packets"?
> Thank you,
> James
>
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