Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

RE: PMD discussion


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.


Pat Gilliland


At 06:17 PM 6/1/00 -0400, you wrote:
>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. 
>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
>	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
>	satisfy our criteria.  I think there is a small subset that the IEEE
>	to standardize that we (I'm talking 100% majority) believe we should
>	our effort on to meet our objectives while providing a small subset
>	satisfy our customer's needs.
>	Cheers,
>	Brad
>			-----Original Message-----
>			From:	Kolesar, Paul F (Paul)
>			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
>	fiber (which has two
>			bandwidth grades), but also included 50 um fiber in
>	grades. These are a
>			400 MHz-km grade (representing the worst installed
>	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
>	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
>	and patch panels
>			are distinctly color coded to distinguish them from
>	fiber types. 
>			I cannot predict the percentage of new versus old
>	since I don't have
>			a crystal ball. But I believe it will be a
>	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
>	equipment in the
>			near term. So the absolute percentage conversion is
>not the
>	key indicator to
>			monitor, but rather the conversion occurring in
>	customers sites.
>			When I look at the 10 port types, I see them serving
>	types of
>			customers. I believe that it will be a rare customer
>	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
>	will not apply
>			for any one customer, all of the choices have their
>	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
>	cabling (the
>			scope of Ethernet up to now), and PHY objectives
>	address both LAN and
>			WAN. Larger and more diverse market spaces will
>	need a greater
>			variety of solutions. 
>			Regards,
>			Paul Kolesar