Hi Mark
I agree that DC application is cost
sensitive.
As many people agreed in some
presentations at meeting, CWDM will be cheaper at near term and serial will
became cheaper in maybe 2011 or beyond.
That means transceiver supplier have to
develop CWDM in 2009 timeframe and serial in 2010 or 11.
This development will cost much. And I do
not think CWDM cost in 2009 or 2010 will be cheaper than 4x10G.
Even more DC application users can choose
8x10G CWDM that has more bandwidth.
I do not think CWDM has superior merit for
DC application.
Also I think there was a presentation that said that DC will start install
40G in 2015 or beyond.
----- Original Message -----
Sent: Wednesday, July 30, 2008
4:08 AM
Subject: Re: [802.3BA] Discussion
on 40G for ="" 10 km SMF
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