Re: RUNT Packets
Yes, I agree with you that we don't need to say anything about it.
The whole thing started with my question for Bob in clause 46 for
the background for the decision of ending packet receiving process
when we see a non-error control character on XGMII. Then someone
asked what's Runt..............I don't know how it got here. But it has
nothing to do with 802.3ae anymore.
Maybe I should have used undersized packets instead of Runt packets.
> 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.
> -----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
> 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.
> "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
> > 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
> > 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
> > __________________________________________________
> > Do You Yahoo!?
> > Yahoo! Calendar - Get organized for the holidays!
> > http://calendar.yahoo.com/