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Re: [802.3BA] 802.3ba XR ad hoc next step concern


The Comparisons_xr_01_0708.xl under CDR option does state 5% cost premium, the input for 5% power premium was provided by the
proposal proponent. 

For cost and power we need to look at current product and then extrapolate instead of accepting everything at face value.  I suggest you
compare XFP vs SFP+ for cost difference.  The current XFP dual CDR PD is 450 mW and I assume in more advance process this
power will be reduced by 1/2. 

If there is real market for >100 m fiber reach there is a trivial solution to extend the fiber reach to 250m .


Chalupsky, David wrote:

The 20% cost premium applies to only one of our proposed XR alternatives.

According to the alternatives spreadsheet (Comparisons_xr_01_0708.xls) the CDR option adds only 5% module cost premium over the base proposal and provides reach of 168m to 251m (across the OM3/4, one-sided/two-sided matrix).


I’m struggling to keep up with the conversation here – but I believe that the 5% alternative addresses the same problem as the 20% alternative, right?


On that assumption I will rephrase Dan’s non-rhetorical question to address a 5% cost adder for 17% increase in coverage:


If I have the choice between:

A) carry two product SKUs: 100m and 150m, with 5% Bill of Material cost delta on the 150m product; or

B) carry only the 150m product

I would accept option B & use only the 150m module even though I know that most of my customers will use it at <100m.


By considering only the bill of material of the module we are missing two aspects of the big picture on cost. 

1) Carrying multiple product SKUs through design, validation, manufacture, customer qualification, customer confusion, etc. adds cost.

Regardless of whether 802.3ba adds a second objective, if the module supplier base develops two different module solutions for 100 & 150m, then the 100m solution will carry an intangible cost burden and the desired 0% cost adder for 100m will not be achieved anyway.

2) The module is not the whole solution.  The CDR module solution does not add cost to the host.  Thus a 5% increase in module cost is less than 5% increase in the total cost of the switch plus modules.


I appreciate that the task force is learning from the history of 10GBASE-SR: that over-specifying the solution had a long term cost impact.

However, we should take away another lesson from 10Gbit:  that providing too many options confuses the customers & slows adoption.


I strongly urge the task force to provide a single solution for parallel MMF.  I believe that it’s worth a 5% cost adder to the module to achieve that.


I really have no personal (or commercial) reason to prefer the CDR option.  I’m just looking at the 5% figure in the spreadsheet & wondering why this isn’t a no-brainer.


Thanks for your time,

Dave Chalupsky



From: Dove, Daniel [mailto:dan.dove@xxxxxx]
Sent: Wednesday, August 27, 2008 4:49 PM
To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3BA] 802.3ba XR ad hoc next step concern


Hi Mike,

We are pretty close to full circle now. :)


Assuming we make the decision that we want to stick with the "standard" model at 100m to keep those customers we would lose by adding cost, does the IEEE standardize a 150m solution or do we let the market solve that problem on its own?


This is not a rhetorical question, although it might appear to be.


Can someone provide any insight on the sensitivity of the market to an additional cost of 20% for every 100m link to satisfy the additional reach?


If the market is insensitive to cost (on this scale) then perhaps the additional reach is justified. If the market is going to be sensitive to that differential cost, then the question falls back to whether the IEEE wants to do a 150m spec or leave it to a market-defned solution.




From: Mike Dudek [mailto:Mike.Dudek@xxxxxxxx]
Sent: Wednesday, August 27, 2008 4:22 PM
To: Dove, Daniel; STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: RE: [802.3BA] 802.3ba XR ad hoc next step concern

Hi Dan


Of course if we don’t increase the cost of the basic Grade A model and have a Grade B version of the same part for extra reach with the Grade B version being loaded with any additional costs of handling two product codes and any additional testing, then we shouldn’t lose any customers.   



Mike Dudek

PMTS Standards & Technology

JDS Uniphase

1480 Arthur Ave.


CO 80027

Tel  303 530 3189 x7533.




From: Dove, Daniel [mailto:dan.dove@xxxxxx]
Sent: Wednesday, August 27, 2008 3:23 PM
To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3BA] 802.3ba XR ad hoc next step concern


Let me re-state one word of that message.


From: Dove, Daniel
Sent: Wednesday, August 27, 2008 2:00 PM
To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3BA] 802.3ba XR ad hoc next step concern

Hi Steve,


Yes that helped a lot. I hope the others on the list are not irritated by my request for repetition of the data.


Given the data, it truly is a challenging issue. I see a 20% premium for a 17% increase in coverage.


This means the confidence in the numbers is exceptionally important and assuming they are accurate, a judgement call by the committee on whether or not a 17% increase in port coverage justifies the 20% increase in cost.


This is important because if you increase the  *COST*  of a solution by 20%, you may decrease the number of customers who are willing to buy it by more than 20%. Thus, in the overall mix, it might turn out to satisfy less customers overall.


Its a pretty challenging judgement call IMHO.


Thanks for providing the data.





fn:Ali Ghiasi
org:Broadcom Corp.
adr;dom:;;3151 Zanker Road;San Jose;CA;95134
title:Chief Architect