Why? Because the debate has been had
repeatedly for every generation of technology that has come and gone and will
probably be had for every generation that is yet to come. The underlying technology
changes and that will change the answer in terms of where the breakpoints lie
between different technologies. Another big thing that changes is the set of
people in the room and different groups will always come up with different
answers based on their different perspectives. But one thing that I believe changes
very little from generation to generation is the reach between different boxes.
My comments are mostly influenced by my perspective on telecommunications applications,
but I suspect the same thing mostly applies to datacenters too. The shape of
the histogram of the number of links plotted vs. the length of those links
probably stays roughly constant. Where the breakpoints are of greatest cost effectiveness
between different fundamental technologies will move depending on bit rate, but
to the first order the number of PMDs probably remains roughly equal.
My thoughts are further influenced by my
expectation that for multi-km reaches we’ll likely end up with Nx10G (or
N/2x20G) WDM PMDs. The smaller the N and the larger the bit rate, the more the
breakpoints are likely to move around.
Drew
_____________________________
Drew Perkins
Chief Technology Officer
Infinera Corporation
1322 Bordeaux Drive
Sunnyvale, CA 94089
Phone: 408-572-5308
Cell:
408-666-1686
Fax:
408-904-4644
Email: dperkins@xxxxxxxxxxxx
WWW : http://www.infinera.com
_____________________________
From: Brad Booth
[mailto:bbooth@xxxxxxxxxxxxx]
Sent: Tuesday, August 22, 2006
10:56 AM
To:
STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [HSSG] Reach
Objectives
Excuse my ignorance, but why? When
10G started, this was an important debate. If they had stuck with the
number of PMDs in 802.3z, then there would have only been two PMDs. The
study group needs to define the markets that it wants to satisfy, and only then
when the study group becomes a task force can the group decide on the actual
number of PMDs required.
Thanks,
Brad
From: Drew
Perkins [mailto:dperkins@xxxxxxxxxxxx]
Sent: Tuesday, August 22, 2006
10:45 AM
To: Brad Booth;
STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: RE: [HSSG] Reach
Objectives
I have a simple proposal to save everyone
a lot of time. Let’s make the baseline plan to stick with exactly the
same number of PMDs with exactly the same reaches as 10GbE. They have all been
developed to fit someone’s requirements. We should have a very high
hurdle to eliminate any of these or add to them.
Drew
_____________________________
Drew Perkins
Chief Technology Officer
Infinera Corporation
1322 Bordeaux Drive
Sunnyvale, CA 94089
Phone: 408-572-5308
Cell:
408-666-1686
Fax:
408-904-4644
Email: dperkins@xxxxxxxxxxxx
WWW : http://www.infinera.com
_____________________________
From: Brad Booth
[mailto:bbooth@xxxxxxxxxxxxx]
Sent: Tuesday, August 22, 2006
10:19 AM
To:
STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [HSSG] Reach
Objectives
The 10km vs. 2km debate occurred in
802.3ae. It was determined that the solution for 2km was virtually the
same as that for 10km; therefore, the task force felt it would be better to
select only one of those reaches and 10km was it. If there is a desire
for 2km and 10km reaches in HSSG, then in my humble opinion, those wishing
to support will need to bring justification forward as to why the study group
should consider possibly increasing the number of PHYs.
Cheers,
Brad
From: Frank
Chang [mailto:ychang@xxxxxxxxxxx]
Sent: Tuesday, August 22, 2006
9:19 AM
To:
STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [HSSG] Reach
Objectives
I agree datacenter for up to 100m. How
about 10GigE LR disctance (10km) or campus 2km discussed earlier?
-----Original Message-----
From: Petar Pepeljugoski
[mailto:petarp@xxxxxxxxxx]
Sent: Tuesday, August 22, 2006
6:02 AM
To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [HSSG] Reach
Objectives
John,
I
believe that the Data
Center distances should
be 100m and 300m.
Petar Pepeljugoski
IBM Research
P.O.Box 218
(mail)
1101 Kitchawan Road,
Rte. 134 (shipping)
Yorktown Heights, NY 10598
e-mail: petarp@xxxxxxxxxx
phone: (914)-945-3761
fax: (914)-945-4134
|
John DAmbrosia
<jdambrosia@xxxxxxxxxxxxxxxxxxx>
08/22/2006
12:37 AM
|
Please respond
to
John DAmbrosia <jdambrosia@xxxxxxxxxxxxxxxxxxx>
|
|
|
To
|
STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
|
|
cc
|
|
|
Subject
|
[HSSG] Reach Objectives
|
|
All,
We
have had some conversation on the reflector regarding reach objectives.
Summarizing what has been discussed on the reflector I see the following
–
Reach Objectives
Long-Haul
--> 100+ km
Metro
--> 10+ km
Data
Center --> 50m & 300m
Data Center Reach Segregation
Intra-rack
Inter-rack
Horizontal
runs
Vertical
risers
Use
this data to identify a single low-cost solution that would address a couple of
the reach objectives
Other Areas
During
the course of the CFI there were individuals who wanted Backplane Applications
kept in for consideration, but I have not heard any further input in this area.
Are there still individuals who wish to propose Backplane as an
objective?
John