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

your procedural guidance is appreciated.  It is precisely the broad market potential that I believe is assisted by a low-cost longer reach PMD.  As I stated in the thread you quoted from:
It is also my understanding that these longer reaches are needed to cover the backbone portions of the data center, which will support traffic aggregated from lower rate channels.  This aggregated traffic represents one of the primary reasons to deploy higher rate Ethernet.  To not provide a low-cost solution for this space is to ignore one of the earliest applications that will drive broad market adoption.

I agree that we did too many PHYs for 10G, but not because of the optics variants, but rather because they were generally multiplied by 2 for LAN and WAN.  It was the PHY multiplier, not the PMDs that was excessive.  To support my point I observe that after we did the original 10GBASE-S, L, E, LX4, we added more in the form of CX4, T and LRM.  Of the original four, the one most heavily disputed was S.  Yet today it represents the largest module market share for 10GbE, despite the fact that it has competition from LX4 and LRM and even L.  I would bet that S volume rivals that of all three combined.  

10GBASE-S serves the data center market, and there is every reason to believe that the data center market will once again prove to be the main market for 40G and 100GbE.  Why do we optimize the longer reach market, dividing it into two distance ranges, 10km and 40km, yet not optimize the short reach market?  In my view, failure to do so is simply foolish.  Taking a closer look, the market for 100BASE-ER4 is certainly smaller than that for a low-cost extended reach PMD, yet the need for 100BASE-ER4 was no more disputed than any other PMD within the broad market potential context.  We have the same situation in the data center, with the exception that the much more costly 10km singlemode PMD stands ready to address the market for distances greater than 100m.  As I have said before, taking such an approach will delay market acceptance of our work because it will drive deployment of link aggregated 10GBASE-S.  It will not drive deployment of 40/100GBASE-LR4, as the cost will be too great for most customers to justify.  If there is a lesson to be learned from 10GbE, its that cost matters.  A second low-cost PMD with extended reach addresses that concern as effectively as possible.

Paul Kolesar
CommScope Inc.
Enterprise Solutions
1300 East Lookout Drive
Richardson, TX 75082
Phone:  972.792.3155
Fax:      972.792.3111
eMail:   pkolesar@xxxxxxxxxxxxx

Geoff Thompson <gthompso@xxxxxxxxxx>

07/11/2008 12:28 PM
Please respond to
Geoff Thompson <gthompso@xxxxxxxxxx>

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


At 09:58 AM 7/11/2008 , Paul Kolesar wrote:

To be completely clear,
I am advocating retention of the 100m objective and the development of a longer reach solution.

for which the "Broad Market Potential"
will be 10 - 15% of the 100 meter PHY
( conclusion drawn from data presented in this thread )

on a project that we felt we "had to do" to fully serve our market
BUT for which most had significant misgivings about the total size of the market.

We currently have fully approved objectives for the PAR in hand.
One of the issues learned from 10Gig was that we did too many PHYs.

Any objective for an additional PHY should be subject to the full scrutiny of the 5 Criteria
especially in the areas of Broad Market Potential and Economic Feasibility.


Geoff Thompson