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RE: Finalizing objective




This has been a source of confusion for many people.

The speed we're talking about is at the MAC/PLS interface before any
encoding is done. For example, if we decided on 8b/10b encoding, the MAC/PLS
i/f would run at 10.000 and the symbol rate on the line would be 12.500. If
we settled on scrambling, the MAC/PLS i/f would still run at 10.000 and the
line rate would also be 10.000. As a final example, if we chose some a
multi-level code, the MAC/PLS would still run at 10.000, but the line rate
may be as low as 2.5 (based on one presentation).

Because 9.58464 and 10.000 are essentially the same order of magnitude, the
MAC/PLS signalling rate and the line code are orthogonal decisions.

Walt

> -----Original Message-----
> From: Bill St. Arnaud [mailto:Bill.St.Arnaud@xxxxxxxxxx]
> Sent: Tuesday, September 07, 1999 7:05 AM
> To: Walter Thirion
> Subject: RE: Finalizing objective
> 
> 
> Walter:
> 
> I have not been able to keep up with all the e-mail on HSSG 
> so I may have
> missed something.  But I don't understand how we can have 
> agreement on speed
> without an agreement on encoding.
> 
> For example if we use 8b/10b coding then there will be enough 
> room to map
> ethernet data at 10.0000 Gbps into SONET frammes.  However if 
> we use NRC
> scrambled coding (like SONET) then the speed becomes a very 
> critical issue
> 
> Bill
> 
> Bill St. Arnaud
> Senior Director Network Projects
> CANARIE
> bill.st.arnaud@xxxxxxxxxx
> +1 613 785-0426
> 
> > -----Original Message-----
> > From: owner-stds-802-3-hssg@xxxxxxxxxxxxxxxxxx
> > [mailto:owner-stds-802-3-hssg@xxxxxxxxxxxxxxxxxx]On Behalf Of Walter
> > Thirion
> > Sent: September 7, 1999 2:46 AM
> > To: 'stds-802-3-hssg@xxxxxxxx'
> > Subject: Finalizing objective
> >
> >
> >
> > At the last meeting, we narrowed the speed objective down 
> to two potential
> > candidates, 10.000 and 9.58464. Since then, there has been a
> > massive amount
> > of discussion on the reflector. At this point, I'd like to 
> see if we've
> > started forming a consensus. On the speed issue ONLY (i.e.
> > without endorsing
> > or putting any limitation on the encoding, line code, management
> > mechanism,
> > etc.), is there any objection to an objective of:
> >
> > 	"A MAC/PLS data rate of 10.000 Gb/s with an optional pacing
> > mechanism to support an effective 9.58464 Gb/s data rate."
> >
> >
> > Walt
> >
>