Re: [802.3BA] 5 Criteria mod to support 40 G on SMF
The study group, the working group, and the EC all agreed that
broad market potential had been demonstrated for both 40 G and
100 G. The broad market potential for 100 G was based, in no small
part, on the needs of very vocal and prominent individuals
representing end users of the technology. These individuals made
it clear that 40 G was not sufficient for their needs. I don't
think that the inclusion of a new objective for 40 G operation
on 10 km of single mode fiber will change their view in the slightest.
They need 100 G, and 40 G in any form simply won't satisfy their needs.
I think that this is well captured in the approved response to the
broad market potential criterion.
What has changed is that a new set of individuals are asking for 40 G
on 10 km of single mode fiber because they believe it will satisfy
their needs. They aren't contradicting the people who want 100 G. They
are simply saying that their needs are different.
Customers tend to be pretty smart people. They know what they need,
they know how to calculate cost/performance ratios, and they know how
to pick the right data rate for each of the links in their networks.
We haven't had any problem with Distinct Identity over the last 16 years
that we have been cranking up the operating speed of Ethernet. Customers
know when to use 10 Mb/s, 100 Mb/s, 1000 Mb/s and 10 Gb/s. They will
be able to draw the same distinction between 40 Gb/s and 100 Gb/s,
regardless of what media types are supported.
I think it would be a terrible idea to limit the link span for 40 G
operation on single mode fiber to 2 km. Customers have been designing
around a maximum link span of 10 km (and the associated channel
insertion
loss) for at least the last decade. It would be wrong to arbitrarily
limit the span of 40 G to 2 km in an attempt to provide unnecessary
differentiation.
Howard Frazier
Broadcom Corporation
-----Original Message-----
From: Brad Booth [mailto:bbooth@AMCC.COM]
Sent: Thursday, February 14, 2008 1:00 PM
To: STDS-802-3-HSSG@LISTSERV.IEEE.ORG
Subject: Re: [802.3BA] 5 Criteria mod to support 40 G on SMF
Steve,
I agree that this does change things up. 40G was positioned as a server
interconnect, and 100G as the network interconnect. The overlap with an
existing 100G objective blurs the distinct identity making it hard to
differentiate the broad market potential for either objective.
If the 40G SMF option was being targeted at a 2 km reach, that would
make sense considering that's a typical campus area network. If someone
then wanted to use that to do 10 km, that would be their option and
considered outside the scope of the standard.
Thanks,
Brad
-----Original Message-----
From: Swanson, Steven E [mailto:SwansonSE@CORNING.COM]
Sent: Thursday, February 14, 2008 1:08 PM
To: STDS-802-3-HSSG@LISTSERV.IEEE.ORG
Subject: Re: [802.3BA] 5 Criteria mod to support 40 G on SMF
Howard etal,
I could agree that this proposal may address what needs to change in our
response to the Economic Feasibility criterion to add the 10km SMF
objective at 40G. However, I think this change goes against the basis of
the decision that we took in July 2007 for considering 40G in the first
place, i.e., segmenting the server and computing applications from the
network aggregation applications. Now the network aggregation space
includes two solutions - 40G and 100G. This seems to place a burden on
us to also re-evaluate Distinct Identity criterion and calls into
question the Broad Market Potential criterion. In reviewing some of the
presentations leading up to our decision to include 40G, I note some of
the concerns expressed then that I think are now back on the table:
* "Fragmentation of R&D efforts (lack of critical mass on either
40G or 100G initially) - two rates will ultimately force component and
equipment vendors to support BOTH."
* "Requires the industry to develop 2 x MACs, 2 x PCS chips, 2 x
PMA (serdes) chips, 2 x N PMDs"
* "Industry confusion on "application versus rate" - Distinct
Identity does not just mean "Is there anything else exactly like this?"
but also "Is there sufficient difference between this and available
alternatives to justify the effort?"
* "Interoperability concerns (some vendors elect to implement 40G
initially, whereas others implement 100G)"
* "Do we now have a triple rate required (40G LAN, 40G WAN, 100G)
since 40G SMF solutions already exist?"
I do not have any proposed changes at this point regarding the BMP or DI
criterion but wanted to express an opinion that these criterion should
be re-evaluated. If others do not share that view, then on we go.
Steve Swanson
Corning Incorporated
-----Original Message-----
From: Howard Frazier [mailto:hfrazier@BROADCOM.COM]
Sent: Thursday, February 07, 2008 6:21 PM
To: STDS-802-3-HSSG@LISTSERV.IEEE.ORG
Subject: [802.3BA] 5 Criteria mod to support 40 G on SMF
Dear members of the IEEE 802.3ba Task Force,
I have reviewed our approved set of 5 Criteria responses
http://www.ieee802.org/3/ba/PAR/HSSG_5C_0707.pdf
looking for any material that will need to be changed in the event we
adopt an objective to support 40 Gb/s operation on 10 km of single mode
fiber. In my opinion, the responses will remain valid and complete, with
one exception.
On page 6 of the above referenced file, in our response to the Economic
Feasibility criterion, we state:
Presentations indicate that for the server market and
computing applications the optimized rate to provide
the best balance of performance and cost is 40 Gb/s.
For the network aggregation market and core networking
applications, the optimized rate offering the best
balance of performance and cost is 100 Gb/s.
If we adopt a 40 Gb/s SMF objective, then this response should be
modified along the lines of:
Presentations indicate that for the server market,
computing applications and some cost-sensitive
aggregation applications, the optimized rate to provide
the best balance of performance and cost is 40 Gb/s.
For the network aggregation market and core networking
applications, the optimized rate offering the best
balance of performance and cost is 100 Gb/s.
The change being the insertion of the words "some cost-sensitive
aggregation applications" in the first sentence.
I think that our previously approved responses for Broad Market
Potential, Compatibility, Distinct Identity, and Technical Feasibility
will not require any change in the event that we adopt an objective for
40 Gb/s operation on SMF. I think that the proponents of the new
objective will be able to readily demonstrate this.
If you think I have over looked something else that might need to be
changed, please speak up, and please provide a proposed change.
Howard Frazier
Broadcom Corporation