RE: PMD discussion
Joel:
The bit rate of CWDM /WWDM is 3.125 Gbps which is way low from 10 Gbps; as a
result, there is no need for excessive data rate concern of 12.5 Gbps. The
main reason for the 64b/66b is to reduce 12.5 Gbps to 10.3125 bps to relief
bandwidth pressure. C/WWDM does not need this 25% bandwidth relief, 8B/10B
at 3.125 Gbps has 75% bandwidth relief already.
Please do not introduce any unnecessary 64b/66b complex coding into the
simple, cost-effective C/WWDM technologies. 8B/10B at 3.125 Gbps is a
efficient, proved technology. Please leave it alone.
Regards,
Edward S. Chang
NetWorth Technologies, Inc.
EChang@xxxxxxxxxxxxxxxx
Tel: (610)292-2870
Fax: (610)292-2872
-----Original Message-----
From: owner-stds-802-3-hssg@xxxxxxxx
[mailto:owner-stds-802-3-hssg@xxxxxxxx]On Behalf Of Rich Taborek
Sent: Monday, May 29, 2000 12:15 AM
To: HSSG
Subject: Re: PMD discussion
Joel,
There are no complete 4-lane serial proposals for WDM on the table which use
a
transmission code other then 8B/10B. The 8B/10B 4-lane serial proposals have
been essentially stable for more than 6 months now. It's getting darn close
to
July, any other candidate transmission codes for WWDM need to get aired very
soon.
Best Regards,
Rich
--
Joel Goergen wrote:
>
> Walter,
>
> I like the second better, but for clarity, I have a question .... for the
> serial solution, my understanding is the thought is to use 64b66b on the
> fiber. What is the general thought for wdm? Is it just 8b10b or is the
> thinking in general that the line interface is 64b66b?
>
> Take care
> Joel
> -----------------------------
>
> Walter Thirion wrote:
>
> > First of all, thanks to everybody that presented PMD proposals at the
last
> > meeting. I've sent my presentation to David Law, so it should be
available
> > on the web site in the next couple of days.
> >
> > In listening to the discussion after my presentation and then going
around
> > and talking to people, it feels to me like we're starting to converge.
Not
> > there, yet, but making progress.
> >
> > The equipment manufacturers made it pretty clear they would like to see
no
> > more than 3 PMDs in the standard. The PMD vendors have some concern that
> > using only 3 PMDs may sub-optimize certain objectives, however, they
could
> > support the 3 PMD position if it is made clear which 3 PMDs the
equipment
> > oems want.
> >
> > Based on an informal straw poll and anecdotal evidence, my opinion is
the
> > first choice would be the set:
> > ________________
> > 850 nm WWDM
> > 1310 nm WWDM
> > 1550 nm Serial
> > ________________
> >
> > If that set isn't feasible, then the 2nd most popular choice is:
> > ________________
> > 850 nm WWDM
> > 1310 nm Serial
> > 1550 nm Serial
> > ________________
> >
> > Thoughts, feedback?
> >
> > Walt
> > ___________________
> > Walter Thirion
> > Chair, IEEE 802.3ae PMD Sub-Task Force
> > 301 Congress Ave.
> > Suite 2050
> > Austin, Texas 78701
> > Voice: 512-236-6951
> > Fax: 512-236-6959
> > wthirion@xxxxxxxxxxxx
> > ___________________
>
> --
> Joel Goergen
> Force10 Networks
> 1440 McCarthy blvd
> Milpitas, Ca, 95035
>
> Email: joel@xxxxxxxxxxxxxxxxxxx
> Direct: (408) 571-3694
> Cell: (612) 670-5930
> Fax: (408) 571-3550
-------------------------------------------------------
Richard Taborek Sr. Phone: 408-845-6102
Chief Technology Officer Cell: 408-832-3957
nSerial Corporation Fax: 408-845-6114
2500-5 Augustine Dr. mailto:rtaborek@xxxxxxxxxxx
Santa Clara, CA 95054 http://www.nSerial.com