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

RE: PMD discussion


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


	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.


			-----Original Message-----
			From:	Kolesar, Paul F (Paul)
			Sent:	Thursday, June 01, 2000 4:06 PM
			To:	'802.3ae'; 'Booth, Bradley'
			Subject:	RE: PMD discussion


			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. 

			Paul Kolesar