RE: PMD discussion
Pat,
I am unclear as to what is meant by VSR. 802.3ae has two short reach
objectives, 100 and 300 m. In your view, is VSR space not covered by these?
Or is VSR sub-100m to you? Either way, I don't see the point of the
discussion unless it is aimed at changing the objectives.
Paul
----------
From: Patrick Gilliland [SMTP:pgilliland@xxxxxxxxxxx]
Sent: Thursday, June 01, 2000 9:34 PM
To: stds-802-3-hssg@xxxxxxxx
Subject: RE: PMD discussion
Paul,
Brad is suggesting, among other things, the VSR
solutions such as 850nm might be best addressed
in a different standard.
I believe Rich Taborek has suggested the same and
is soliciting proposals for the Fibre Channel PMD
working group. Probably the natural place for this
work might be a different forum. Otherwise, we must
ask the entire membership to reexamine the objectives.
I see no future in delaying the standard by maintaining
an 850nm voting block. If the membership does not want
to standardize VSR applications within 802.3, let's take
it to a different forum where it is of primary interest.
Regards,
Pat Gilliland
patgil@xxxxxxxxxxx
--------------------------------------------------------
At 06:17 PM 6/1/00 -0400, you wrote:
>
>Brad,
>
>There are no PMDs in the set of 5 that do not meet at least one of
the
>objectives. As far as the 850 nm serial PMD, I believe I made a
strong case
>at the May interim as to why it also broadly meets the criteria.
80% of the
>market for 10GbE will be under 300 m. A solution optimized for this
large a
>portion of the market has broad market application regardless of
the number
>of distance objectives it covers.
>
>To your point on a small subset getting 100% majority, the
indication of the
>straw poll from the May interim is that down selecting below 5 PMDs
this is
>going in the wrong direction to achieve consensus. The poll
indicated that
>the 5 PMD set was favored by roughly 2 to 1 compared to the closest
>alternative of 3 PMDs. Further, I believe that the 3 PMDs are not
the same 3
>among the supporters of that choice, which subdivides the support.
From my
>perspective an inclusive approach will work better than an
exclusive
>approach in getting to consensus. In an inclusive approach you get
the PMDs
>you prefer, while others also get the PMDs they prefer. If you
really
>believe the market will be best served by some subset of the PMDs,
you are
>free to use only those.
>
>Regards,
>Paul Kolesar
>
>
> ----------
> From: Booth, Bradley [SMTP:bradley.booth@xxxxxxxxx]
> Sent: Thursday, June 01, 2000 5:19 PM
> To: '802.3ae'
> Subject: RE: PMD discussion
>
>
> Paul,
>
> You touched on a key point. To quote you, "The norm is
likely a
>choice
> between a small subset that is targeted for their needs." I
see
>this as
> applying directly to what we need to work on. If there is
something
> available from another standards body (i.e. VSR VCSELs),
then I
>would prefer
> to leave that effort in that standards body especially if it
doesn't
>broadly
> satisfy our criteria. I think there is a small subset that
the IEEE
>needs
> to standardize that we (I'm talking 100% majority) believe
we should
>focus
> our effort on to meet our objectives while providing a small
subset
>to
> satisfy our customer's needs.
>
> Cheers,
> Brad
>
> -----Original Message-----
> From: Kolesar, Paul F (Paul)
>[mailto:pkolesar@xxxxxxxxxx]
> Sent: Thursday, June 01, 2000 4:06 PM
> To: '802.3ae'; 'Booth, Bradley'
> Subject: RE: PMD discussion
>
> Brad,
>
> 802.3z not only supported the installed base
of 62.5
>um
> fiber (which has two
> bandwidth grades), but also included 50 um
fiber in
>two
> grades. These are a
> 400 MHz-km grade (representing the worst
installed
>base
> grade of 50 um) and
> a newer 500 MHz-km grade that allowed the SX
>solution to
> meet the 550 m
> distance objective. I don't think customers
have had
>a
> difficult time
> getting GbE technologies to work in this
situation.
>But we
> are sensitive to
> this issue. So recognizing the need to
distinguish
>new MMF
> from old, Lucent
> has made the new fiber easily identifiable.
New MMF
>cable
> and patch panels
> are distinctly color coded to distinguish
them from
>other
> fiber types.
>
> I cannot predict the percentage of new
versus old
>fiber,
> since I don't have
> a crystal ball. But I believe it will be a
>significant
> amount with
> conversion accelerating as other fiber
suppliers
>come on
> line. Lucent
> already shipped hundreds of kilometers of
new MMF
>and we are
> still ramping
> up production. Also, I believe that
deployment will
>tend to
> occur most
> rapidly in those customer sites that intend
to use
>10GbE
> equipment in the
> near term. So the absolute percentage
conversion is
>not the
> key indicator to
> monitor, but rather the conversion occurring
in
>10GbE
> customers sites.
>
> When I look at the 10 port types, I see them
serving
>several
> types of
> customers. I believe that it will be a rare
customer
>that
> must make a choice
> between all 10 types. The norm is likely a
choice
>between a
> small subset
> that is targeted for their needs. While most
of the
>choices
> will not apply
> for any one customer, all of the choices
have their
>purpose
> in serving the
> entire customer base. Let's not loose site
of the
>fact that
> 802.3 is
> entering new market spaces. These new spaces
are
>embodied in
> the 10 and 40
> km distance objectives that far exceed the
scope of
>building
> cabling (the
> scope of Ethernet up to now), and PHY
objectives
>which
> address both LAN and
> WAN. Larger and more diverse market spaces
will
>naturally
> need a greater
> variety of solutions.
>
> Regards,
> Paul Kolesar
>
>
>