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Re: XAUI and 64b/66b


Again, you are twisting the issues of XAUI.

1.There is NO market potential for XAUI because is a hidden interface that
is not part of the customer offering.

2. XAUI was presented as being an optional implementation practice, which
means that it could be left out of any implementation without any
consequences to interoperability.  It also means that any PCS that has 8B10B
as a precoding requirement can not be considered and stay within the
definition of "optional".  I noticed that a vote on continuing development
on "Hari" which is the main ingredient in XAUI was avoided at the last

3.  The vendors that started their silicon based on "Hari" before
alternative codings, particularly for a WAN compatible PHY, can build LAN
only switches with the LAN only PHY that they originally intended.  I had
hoped that they would not continue to sabotage the efforts to produce an
effective WAN compatible PHY that did not include their legacy encoding
scheme, even after the compromise to separate the efforts.  To say ""We and
they" are planning to make LAN PHYs as well as provide multiple solutions
for the MAN/WAN. All of those solutions will provide optional support for
XAUI/XGXS" is to say that they intend to have what ever is standardized,
provide an additional market for the 8B10B encoding of "XAUI".

I do not see the proposal of the "UniPHY" as an effort to "standardize the
pieces that are similar" between the PHYs, when there was very little
similarity other than potentially in the serial optical transceivers.  This
was the reason that there was so much support for the compromise of having
two separate PHYs in the objectives.  I see the "UniPHY" as an effort to try
to put the previously mentioned LAN chips into the expanding potential
market of Ethernet in the WAN.  If the LAN people were able to conceive any
other use for Ethernet, particularly in service provider based WAN markets,
they may have used some other coding scheme.  Of course it would have
required them to take their potential market a little less for granted.

I also do not see XAUI as being a requirement except for legacy vendors with
legacy form factors based on their preconceived notion of what a 10 Gigabit
interface would physically require.  I find it fascinating that none of the
existing 10 Gigabit transport vendors use that kind of large PCB form
factor.  Could it be that the 10 Gigabit transport vendors figured out
something that the legacy LAN vendors did not pay attention to, or were
unwilling to learn from?  Perhaps the legacy LAN vendors in their $50+
billion market thought they were smarter and knew better than the 10 Gigabit
transport vendors in their $1+ trillion market?

All I can do is observe the actions of the individuals involved with "Hari",
and now "XAUI", to be able to determine what their agenda is.  I can not
ascribe to their actual thoughts or words amongst themselves.  I know that
several non-"Hari/XAUI" individuals have attempted to be accommodating by
allowing it in as an optional implemenation practice, only to have it used
against them by having a "UniPHY" that has 8B10B as a precoding requirement
now be pushed.

I am not a vendor.  I am a customer.  Within the company that I work for, I
establish the requirements for technologies that get deployed.  I do work
for a data switch vendor nor do I own stock in a data switch vendor, and
have no financial agenda for a particulary solution.  I only want what I
perceive as best for the industry and the customers that it supports.

Thank you,
Roy Bynum

----- Original Message -----
From: Rich Taborek <rtaborek@xxxxxxxxxxx>
To: HSSG <stds-802-3-hssg@xxxxxxxx>
Sent: Thursday, March 23, 2000 3:01 AM
Subject: Re: XAUI and 64b/66b

> Roy,
> Once again, XAUI/XGXS is optional, please don't be compelled to endorse
> At this point XAUI/XGXS meets and exceeds Critter #1 Broad Market
Potential in a
> manner unparalleled by any other 10 GbE proposal with the exception of the
> Serial LAN PHY (which supports XAUI/XGXS).
> There are NO other complete proposals on the table which address the many
> and backplane interconnect requirements. Please consider this statement as
> challenge, because if there is something out there that is better than the
> current XAUI/XGXS proposal, I'm interested in building chips to it. Time
is also
> running out for new proposals so be quick about getting your competing
> aired before July '00. BTW, that'll be close to the timeframe that
> chips should be sampling from multiple vendors.
> "We and they" are planning to make LAN PHYs as well as provide multiple
> solutions for the MAN/WAN. All of those solutions will provide optional
> for XAUI/XGXS.
> As an individual IEEE member, I find your recent threads related to 8B/10B
to be
> somewhat counter-productive to the 10 Gigabit Ethernet standardization
effort. I
> suggest you "move on" to more productive threads.
> Best Regards,
> Rich
> --