Re: [HSSG] Reach Objectives
Eric,
Today many suppliers in the structured
cabling environment terminate test multistrand cables in the factory. I
believe that for distances up to 100m this will be the norm in the future.
While I agree that the CWDM optics may
be attractive, the density, very tight power budget and the power consumption
requirements in HPC and servers make it secondary choice to parallel.
Regards,
Peter
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
| "Eric B. Grann"
<ebgrann@xxxxxxxxxxxxx>
08/22/2006 07:54 PM
|
Please respond to
"Eric B. Grann" <ebgrann@xxxxxxxxxxxxx> |
|
|
To
| STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
|
|
cc
|
|
|
Subject
| Re: [HSSG] Reach Objectives |
|
Ali,
If the datacenter is set up
to handle pre-terminated cables at 100m, than ribbon fiber is a potential
solution. However, if the datacenter requires field termination,
than ribbon fiber is not easy to work with. Additionally, when one
includes the cost of the fiber in the equation for total link cost, the
cross-over point between parallel optics and CWDM optics (for multimode
fiber only) is around 15m. At this point, I would not conclude that
parallel optics is the most cost effective solution for a 100m target.
On another note, I am hopeful
that this potential standard will not try to force an “all in one solution”
like 10G Ethernet did. If this standard sets an objective for both
multimode and single mode, a PMD set should not be forced to tackle both
issues. If this approach had been taken in 10G Ethernet, we might
have had more cost effective solution for 300m over installed multimode
fiber, and not have a single-mode transmitter that never sees a single-mode
fiber.
Regards,
Eric Grann
Omron Network Products
From: Ali Ghiasi [mailto:aghiasi@xxxxxxxxxxxx]
Sent: Tuesday, August 22, 2006 1:13 PM
To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [HSSG] Reach Objectives
Roger and Mat
Generally in the data center it is more desirable to use multi-mode fiber
for ease of use, handling, and termination.
I prefer to make the ribbon fiber MMF and use CWDM on SMF. Because
of the ribbon cable cost I don't see
a reason to define length beyond the datacenter (100 m) or define an SMF
ribbon PMD.
Thanks,
Ali
Roger Merel wrote:
Agree with Matt that once you
are considering a new cable (ribbon MMF), the considerations are different,
and SMF make the distinction between 50m/100m/300m/2km irrelevant. One
PMD should address all of them.
However, the optimal solution
may not be parallel SMF fibers but rather multiple-lambdas over a single-pair
of SMF. In which case you don’t have to suffer the cost of ribbon
fiber (of either SMF or OM3) which can be less economically attractive
both “per meter” and “per patch panel”.
-Roger
From: Matt Traverso [mailto:matt.traverso@xxxxxxxxx]
Sent: Tuesday, August 22, 2006 1:47 PM
To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [HSSG] Reach Objectives
Hi Petar, John,
Since the OM3 fiber we are discussing would primarily be parallel, is there
merit in defining an OM3 PMD versus specifying a parallel SMF based
PMD?
My assumption is that in both cases the data center in question would be
pulling new fiber. If my assumption is true, then we should not limit
our consideration to OM3,but should also look at SMF. For example
SMF would allow for the extension to greater distances more simply.
There may indeed be merit in defining the data center PMD to be OM3 based,
but my opinion is that we should not jump to conclusions.
thanks
--Matt Traverso
Opnext, Inc.
mtraverso@xxxxxxxxxx
Note - I sent this from a personal account to avoid an automated statement
from my IT dept which contains phrases that would likely be considered
"unfriendly" to the reflector.
On 8/22/06, Petar Pepeljugoski
<petarp@xxxxxxxxxx>
wrote:
Brad,
I agree with you. And the breakpoints vary from solution to solution.
Let's consider the following two examples:
1. N ch. x 10 Gb/s over OM3 fiber at 50m, and at 100m, there is very little
difference in the specs, so the cost will most likely not be affected.
2. M ch. x 17 Gb/s (or 20 gb/s) over OM3, there will be much larger difference
between 50m and 100m and there might be cost premium.
This will depend on the expected yield distribution and how sensitive is
to changes in the specs. So, we will need to carefully tread and not become
prisoners to the reach objectives, but rather optimize the cost.
From our perspective, there are distances up to 150m, but the largest distances
are not so common, so that is why I proposed the 100m.
Whatever is not covered by the 0-100m, should be covered by the next PMD
(most likely SMF based). That will reduce the cost by giving it additional
volume, while the short distance on the MMF will drive the cost by increasing
the yield.
Regards,
Peter
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
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
John/Petar;
I agree datacenter for up to 100m. How about 10GigE LR disctance (10km)
or campus 2km discussed earlier?
Frank
-----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
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