RE: Equalization and benefits of Parallel Optics.
Roy and Bruce,
If there were any such preliminary claims made for 850 serial regarding its
capability to 100 m on the installed base, (and I do not recall any) it
would have had to have been with the understanding that the "installed base"
contained 500 MHz-km 50 um fibers. Using 500 MHz-km bandwidth in the link
model results in distances approaching, but short of, 100 m.
I do not believe that the 100 m objective was chosen because of any such
claims. As I have stated before, I believe the 100 m objective was chosen
because we though that some reasonable solution would be able to achieve
this objective, not necessarily 850 nm Serial.
Now upon further examination of the rationale behind that objective, we
find it is rather empty. It neither protects a significant customer
investment, nor necessarily addresses a particular distance need tied to an
application space where 10GbE is expected to be deployed.
As such it is probably better to replace it with a more meaningful
objective, one that addresses the needs of the equipment room. To develop a
better objective for the equipment room, we will need data on distance
distributions. Today we heard from Chris Diminico that equipment room
distance distribution data is available. I suggest examining it and setting
up the appropriate objective around this data.
Paul
----------
From: Bruce Tolley [SMTP:btolley@xxxxxxxxx]
Sent: Friday, August 04, 2000 3:56 PM
To: Roy Bynum; Paul Bottorff; Booth, Bradley;
stds-802-3-hssg@xxxxxxxx
Subject: RE: Equalization and benefits of Parallel Optics.
Roy:
I agree in part. My recollection is that according to statements
made in
the ad hocs and during the York meeting one year ago, the 850 nm
proponents
thought they could obtain distances100 meters over installed, low
bandwidth
MM fiber. I do not recall any promises being made and I do not think
any
were implied since at that time almost all the work was very
preliminary.
Bruce
At 08:37 AM 8/2/00 -0500, Roy Bynum wrote:
>Paul,
>
>As part of the distance Ad Hoc, I was under the impression that the
300m
>objective was for new technology MMF in the building risers. The
Ad Hoc
>was told that 100m over "installed" MMF was feasable at a symbol
rate of
>over 10Gb, equivalent to the proposed 850nm serial PMD. Were we
>mislead? I don't know. As a customer participating in this
process and
>going back to looking at the most likely areas of initial
implementation
>and the implementation practices, I am the more serious about
holding the
>people that said that they could do the serial 850nm PMD to their
implied
>promise.
>
>Thank you,
>Roy Bynum
>
>
>At 01:33 PM 7/27/00 -0700, Paul Bottorff wrote:
>
>>Brad:
>>
>>I also understand our objectives in the same way. We don't have an
>>objective for 100 m computer room connections. It seems to me the
300 m
>>objective was written for computer rooms. The 300 m over MMF could
be
>>applied to any fiber solution.
>>
>>Cheers,
>>
>>Paul
>>
>>At 12:55 PM 7/27/2000 -0700, Booth, Bradley wrote:
>>
>>>Ali,
>>>
>>> From my understanding of the objectives, the task force doesn't
have a
>>>distance objective of "100m data center applications." We do
have an
>>>objective for 100m over installed MMF fiber. That 100m distance
objective
>>>was chosen because it reflects what is used in the data center
applications.
>>>If the task force satisfies the objective (which is a requirement
for the
>>>task force to do), then we provide a solution for the
application. The
>>>reverse is not true. If task force satisfies the application,
then we don't
>>>meet our objectives.
>>>
>>>Given that the task force has to satisfy objectives first and
foremost, I
>>>believe that it is key that the task force focus on those
proposals that in
>>>some manner satisfy an objective. As I see it, parallel optics
and parallel
>>>fiber do not satisfy any of our objectives; therefore, the task
force needs
>>>to work on the ones that will satisfy our objectives.
>>>
>>>Cheers,
>>>Brad
>>>
>>> -----Original Message-----
>>> From: ghiasi [mailto:Ali.Ghiasi@xxxxxxxxxxx]
>>> Sent: Thursday, July 27, 2000 2:17 PM
>>> To: stds-802-3-hssg@xxxxxxxx;
bradley.booth@xxxxxxxxx
>>> Cc: Ali.Ghiasi@xxxxxxxxxxx
>>> Subject: RE: Equalization and benefits of
Parallel
>>>Optics.
>>>
>>> Brad
>>>
>>> > From: "Booth, Bradley"
<bradley.booth@xxxxxxxxx>
>>> > To: stds-802-3-hssg@xxxxxxxx
>>> > Subject: RE: Equalization and benefits of
Parallel
>>> Optics.
>>> > Date: Wed, 26 Jul 2000 18:29:56 -0700
>>> > MIME-Version: 1.0
>>> > X-Resent-To: Multiple Recipients
>>><stds-802-3-hssg@xxxxxxxxxxxxxxxxxx>
>>> > X-Listname: stds-802-3-hssg
>>> > X-Info: [Un]Subscribe requests to
>>>majordomo@xxxxxxxxxxxxxxxxxx
>>> > X-Moderator-Address:
>>>stds-802-3-hssg-approval@xxxxxxxxxxxxxxxxxx
>>> >
>>> >
>>> > I have one question:
>>> >
>>> > Which of our distance objectives is satisfied
with
>>>parallel fiber and
>>> > parallel optics?
>>>
>>> The 100 m data center applications.
>>> >
>>> > It has been my interpretation that when we
talked about
>>>100m of installed
>>> > base of MMF, that we were referring to the MMF
fiber
>>>currently available for
>>> > use by 802.3z. Parallel optics does not
operate over
>>> this
>>>installed base.
>>>
>>> You are correct parallel optics would not
operate over an
>>>installed two fiber
>>> plant. Parallel optics would loose if you go in
to an
>>>installed fiber base.
>>> What I suggested was 100m data center
applications, where
>>>the fiber are not
>>> installed in the building wiring.
>>>
>>> Data center application are very significant as
stated in
>>>the last meeting
>>> about half the total market. Solutions
significantly lower
>>>cost targeted
>>> for sub 100 m is needed, otherwise there will
several
>>>proprietary solutions.
>>> Parallel optics is the lowest cost, almost
mature after 3
>>>years, lowest power,
>>> and smallest foot print. Parallel optics is
ideal to get
>>>bandwidth off the
>>> edge of your board.
>>>
>>> Serial 850 or CWDM 850 can be another candidate
for low
>>> cost
>>>data center
>>> applications by having cable advantage over
parallell
>>> fiber.
>>>But you need
>>> to offset fiber advantage against power, size,
cost,
>>>testing, and maturity.
>>>
>>> >
>>> > Or am I missing the point here?
>>> >
>>> > Cheers,
>>> > Brad
>>>
>>> Thanks,
>>>
>>> Ali Ghiasi
>>> Sun Microsystems
>>>
>>> >
>>
>>Paul A. Bottorff, Director Switching Architecture
>>Enterprise Solutions Technology Center
>>Nortel Networks, Inc.
>>4401 Great America Parkway
>>Santa Clara, CA 95052-8185
>>Tel: 408 495 3365 Fax: 408 495 1299 ESN: 265 3365
>>email: pbottorf@xxxxxxxxxxxxxxxxxx
>