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Re: [802.3BA] XR ad hoc Phone Conference Notice

I agree with what you say; my preference has been/is to add another objective but there has been reluctance by others to add another PMD for several reasons including that we will get wrapped around the distinct identity issue even though we have violated that "critter" in the past. So we have been trying to exhaust other avenues prior to adding an objective.
I think my position is clear:
  • I would support another MMF objective, say 150m on OM3 and 250m on OM4 per Jewell (although other means are also acceptable to me)
  • I support the low cost baseline, but by itself, it is not sufficient
  • My customers prefer 1 PMD (zero polled think 100m is adequate) but would likely accept 2
  • I am technology agnostic in how we get to longer reach
  • I prefer a normative requirement to support longer reach but would not oppose an informative approach
Bottom-line: The only thing that I would oppose is a 100m-only solution; I would support any means to get to an extended reach solution that we can get consensus on but it is not clear to me what that is........

From: John DAmbrosia [mailto:jdambrosia@xxxxxxxxxxxxxxx]
Sent: Thursday, July 10, 2008 10:38 AM
To: Swanson, Steven E; STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: RE: [802.3BA] XR ad hoc Phone Conference Notice


Your comment below could be interpreted that something has stopped the group from making a motion regarding a new objective for MMF.  I do not recall any motion (or straw poll) regarding adding a 2nd MMF objective ever being made.  This is different than the SMF scenario described below, where separate motions for each of the distances were made.  (> 10km over SMF adopted Motion #5 11/06 plenary meeting and > 40km over SMF adopted Motion #5 at 1/07 interim meeting).


Furthermore, I gave a presentation to the XR over Parallel Fiber Ad hoc ( where the topic was discussed as well in relation to distinct identity.  I also addressed this issue in an email to Paul Kolesar (, and observed that I saw three general routes that the ad hoc might choose in forming a proposal:

1)       handle extended reach in some sort of informative manner

2)       modify the existing solution in some manner

3)       propose a new objective that enables a second solution


To date I have still not heard anyone propose adding a new objective.  If such a course were to be pursued, it would be advisable to do at the coming plenary meeting, so that the added objective could be confirmed by the WG.








From: Swanson, Steven E [mailto:SwansonSE@xxxxxxxxxxx]
Sent: Thursday, July 10, 2008 8:30 AM
To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3BA] XR ad hoc Phone Conference Notice




Just to be crystal clear, the objective reads:


"at least 100m on OM3 MMF"

While I agree that 100m meets that objective, Kolesar and I presented data in November 2006 noting that 100m was not adequate. We were assured that longer link lengths could be accommodated because of the words "at least." This was my beef in Munich.

In a survey of our customers 0/20 said that 100m was adequate and that MMF was preferred over SMF where possible.

I still don't understand why it is OK to have two link length objectives for SMF (and we considered a third (2-4km)) but we can't have two link length objectives for MMF. Better yet from my point of view is to have one PMD that satisfies both - the premium that we are talking about at the module level (estimated at ~20%) is in the noise for 40/100.

We need a compromise here of some sorts.



From: Brad Booth [mailto:bbooth@xxxxxxxx]
Sent: Wednesday, July 09, 2008 11:11 PM
To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3BA] XR ad hoc Phone Conference Notice

That's an excellent point.  I'm glad that Jeff brought this up.


The objectives state 100m on OM3.  That is the requirement of the project and one by which the draft standard will be judged.  There is no requirement to satisfy a non-objective.





Brad Booth
Sr. Principal Engineer, AMCC

From: Petar Pepeljugoski [mailto:petarp@xxxxxxxxxx]
Sent: Wednesday, July 09, 2008 9:51 PM
To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3BA] XR ad hoc Phone Conference Notice


If I interpret correctly, you are saying that all users should amortize the cost of very few who need extended reach.
We need to be careful how we proceed here - we should not repeat the mistakes of the past if we want successful standard.



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


Frank Chang <ychang@xxxxxxxxxxx>




07/09/2008 10:29 PM


Re: [802.3BA] XR ad hoc Phone Conference Notice


Hi Jeff;
Thanks for your comment. You missed one critical point that there is cost increase from OM3 to OM4. If you take ribbon cable cost in perspective, OM4 option is possibly the largest of the 4 options.
Besides, the use of OM4 requires to tighten TX specs which impact TX yield, so you are actually compromising the primary goal.

From: Jeff Maki [mailto:jmaki@xxxxxxxxxxx]
Wednesday, July 09, 2008 7:02 PM
Re: [802.3BA] XR ad hoc Phone Conference Notice

Dear MMF XR Ad Hoc Committee Members,
I believe our current objective of “at least 100 meters on OM3 MMF” should remain as a primary goal, the baseline.  Support for any form of extended reach should be considered only if it does not compromise this primary goal.  A single PMD for all reach objectives is indeed a good starting premise; however, it should not be paramount.  In the following lists are factors, enhancements, or approaches I would like to put forward as acceptable and not acceptable for obtaining extended reach.
Not Acceptable:
1. Cost increase for the baseline PMD (optic) in order to obtain greater than 100-meter reach
2. EDC on the system/host board in any case
3. CDR on the system/host board as part of the baseline solution
4. EDC in the baseline PMD (optic)
5. CDR in the baseline PMD (optic)
1. Use of OM4 fiber
2. Process maturity that yields longer reach with no cost increase
In summary, we should not burden the baseline solution with cost increases to meet the needs of an extended-reach solution.
Jeffery Maki
Jeffery J. Maki, Ph.D.
Principal Optical Engineer
Juniper Networks, Inc.
1194 North Mathilda Avenue
Sunnyvale, CA  94089-1206

Voice +1-408-936-8575
FAX +1-408-936-3025