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