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John,
I
agree some reflector discussion would be helpful on this
topic.
I
characterize the discussion I heard around the choice of PMD as really boiling
down to a debate on the primary applications and the drivers for those
applications.
The original justification for adding the 40G SMF objective was primarily
based on the application of Data Center inter-switch links. There was also
other applications such as for use in interconnecting to OTN equipment
which is good for BMP. In both cases lower cost solutions are
preferential. The debate appears to revolve around what other assumptions
there are around market timing, technology risks, cost projections and
operational issues etc.
To me the simple view is that to achieve low cost, you need higher
volume. Higher volume is achieved by the having a solution that addresses
the largest primary application and as many others as possible. I am
assuming that the primary application is still the DC.
Since DC applications are inherently much more sensitive to cost, a near
term low cost solution is needed or else the application will likely not be
adopted. In this case, if 40G SMF PMD is uneconomical in the near term
then the DC users will likely stay with nx10G as long as possible and then
presumably assess the 40G/100G economics at some later date.
The argument for adopting serial technology now is that the potential
higher volume of the DC application will trigger the necessary development
investments now and drive the cost of that technology down so we will ultimately
get it to the low cost solutions needed. My concern is that the timing and
cost windows needed for the DC application do no fit with that model and we
would end up with little adoption in that market and end up with a lower volume,
higher cost PMD which is what we would all like to avoid.
Mark
Dear Task Force
Members,
Per Motion #9 from July, the
editorial team is working on creating a “a draft
based on adopted baseline proposals for circulation prior to the September
2008 interim meeting
.”
Unfortunately, at the July meeting the Task Force
did not reach consensus on a baseline proposal to satisfy the 40G over =>
10km SMF objective. Therefore, in
September we need to reach closure on this issue.
With that said, I
would like to strongly recommend that the TF make use of the reflector to
discuss the various issues of debate that have been going on, both during the
meetings and during offline discussions.
Let’s use the next
several weeks to have meaningful debate so we can reach consensus at the
September meeting.
Regards,
John
D’Ambrosia
Chair, IEEE P802.3ba
Task Force
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