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
Please respond to
Brad Booth <bbooth@xxxxxxxxxxxxx>
To
STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
cc
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.
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
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?