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
>
>
>