Re: Unified PMD vs. Unified PHY
Rich,
The original compromise was to have separate LAN and WAN PHYs. Now a group
of people is trying to compromise on the compromise by compromising the best
features of both of the separate PHYs in a continuing attempt to justify an
8B10B precoding to everything else by calling it another name. This is the
same problem that was had with the "hari" proposals. The "UniPHY" as
proposed is nothing more than the original 10.00 Gb 8B10B LAN PHY attempting
to "shoe horn" itself into the WAN PHY and being an additional 3% less
efficient doing it.
I know that you have an emotional attachment to 8B10B. I know that at least
one large LAN vendor has already done an ASIC using 8B10B out of the MAC.
Not using 8B10B does not preclude the LAN vendor from having his LAN PHY
based on block encoding, 8B10B or 64B/66B; while allowing the WAN vendors
from having a non-8B10B solution. Please do not presume that one solution
will be best for all implementations.
Thank you,
Roy Bynum
----- Original Message -----
From: Rich Taborek <rtaborek@nSerial.com>
To: HSSG <stds-802-3-hssg@ieee.org>
Sent: Sunday, March 19, 2000 12:17 AM
Subject: Re: Unified PMD vs. Unified PHY
>
> Roger,
>
> The problem we're having is that the leading proposals for the LAN, WAN
and Uni
> PHY's are all proposing putting different things on the wire. This doesn't
help.
> Therefore, the UniPHY may be the "compromise" solution since it would
result in
> one definition of what's on the wire.
>
> Best Regards,
> Rich
>
> --
>
> Roger Ronald wrote:
> >
> > If you ask a question that only considers benefits and not costs, the
answer will be
> > skewed and (IMHO) fairly meaningless.
> >
> > Is one PHY better than two? Sure.
> >
> > Is one PHY better than two if the cost for the part is tripled.
Absolutely not!
> >
> > How about if having both PHY capabilities increases the power budget by
a factor of
> > 50% over each individually?
> >
> > If a part can meet the standards for operating in the mode of operation
that
> > the vendor chooses to support, it should be acceptable. It should not be
unacceptable
> > just because it might be "better" if it could also do other things.
> >
> > If someone wants to make a LAN only PHY, why not let them?
> > If someone wants to make a WAN only PHY, why not let them?
> > If someone wants to make a UNI PHY, why not let them?
> >
> > Standards groups (again IMHO) should define standards, not
implementations. I.e.
> > define what is on the wire, not how it gets there.
> >
> > RR
> > ----- Original Message -----
> > From: Rich Taborek <rtaborek@nSerial.com>
> > To: HSSG <stds-802-3-hssg@ieee.org>
> > Sent: Tuesday, March 14, 2000 4:41 PM
> > Subject: Re: Unified PMD vs. Unified PHY
> >
> > >
> > > Bruce,
> > >
> > > Well said! This was also my interpretation of the survey results. If
there were
> > > only one question on the survey, UniPHY vs. separate LAN and WAN PHY,
I believe
> > > that the survey results would be the same (i.e. strongly in favor of a
UniPHY).
> > >
> > > Best Regards,
> > > Rich
> > >
> > > --
> > >
> > > Bruce Tolley wrote:
> > > >
> > > > At 08:33 AM 3/14/00 -0600, Roy Bynum wrote:
> > > > > I think that the original compromise and
> > > > >the objectives as stated are correct, there needs to be seperate
LAN and WAN
> > > > >PHYs.
> > > >
> > > > Roy:
> > > >
> > > > I think in the first part of your statement you hit the nail on the
head. Goal #9 (Define two families of PHYs) was a
> > compromise that came out of several meetings that was aided by the
bridge diagram originally proposed by Howard Frazier.
> > > >
> > > > Many folks have since expressed displeasure with the idea of a
bridge but the picture gave the members of the study group a way
> > to understand and bound the problem.
> > > >
> > > > The goal of two PHYs agreed upon in York was as much political
statement as it was a technical statement. There was a strong
> > feeling up to the meeting in York of the need to limit the problem,
define the goals, and get on with the work.
> > > >
> > > > It was always clearly stated that the goals were not written in
stone and we might come back to revise them.
> > > >
> > > > Given the basis of the findings from survey conducted by Jonathan, I
conclude that there is strong support among the members of
> > the task force to seriously investigate the concept of the UniPHY.
> > > >
> > > > Bruce
> > >
> > > -------------------------------------------------------
> > > 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@nSerial.com
> > > Santa Clara, CA 95054 http://www.nSerial.com
>
> -------------------------------------------------------
> 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@nSerial.com
> Santa Clara, CA 95054 http://www.nSerial.com
>
>