Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

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

I donot know how to interpret your comment "in reality the number of people who need 300m is close to 0". Have you verified your statement with those folks who have spent so many years to develop the various LX4, LRM, SFP+ plus shipping the Xenpak, X2, XFP, SFP+ Modules and Systems associated to meet those specs.
Also I believe these folks well understood what they (or their customers) were looking for before investing money/time, i.e, there was a market or demand there, I believe the same for XR extended reach today. 
My understanding the ad hoc group led by Alessandro/John is giving enough thoughts to address your concern to avoid amortize the cost.

From: Gourgen Oganessyan [mailto:gourgen@xxxxxxxxxxx]
Sent: Wednesday, July 09, 2008 8:02 PM
To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3BA] XR ad hoc Phone Conference Notice


Well, sadly that’s what has been happening in the 10G world, people are forced to amortize the cost of 300m reach (LRM), while in reality the number of people who need 300m is close to 0.

That’s why I am strongly in support of your approach of keeping the 100m objective as primary goal.


Frank, OM4 can add as much cost as it wants to, the beauty is the added cost goes directly where it’s needed, which is the longer links. Alternatives force higher cost/higher power consumption on all ports regardless of whether it’s needed there or not.


Gourgen Oganessyan


Quellan Inc.

Phone: (630)-802-0574 (cell)

Fax:     (630)-364-5724

e-mail: gourgen@xxxxxxxxxxx

From: Petar Pepeljugoski [mailto:petarp@xxxxxxxxxx]
Sent: Wednesday, July 09, 2008 7:51 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