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Re: [802.3_100GNGOPTX] Minutes Uploaded - Forward Direction



Ali,

We have to keep in mind we are talking about *cost*.

For example, when we look at the media *cost* we compare the relative cost of using two 12-lane fiber bundles, versus one. The media difference is about 2x although I am not including connectors and assembly which has to occur in either case and might nullify the difference a bit.

For an optical interface, we have 10 VCSELs @ 10Gb vs 4 VCSELs @ 25Gb. If you assume the higher speed VCSELs will eventually yield a small cost adder of 20%, then its (10x1)/(4*1.2)or relative cost of 48% for SR4 optics. You can do similar things on the ROSA side of the optics.

On the silicon side, we can assume that 10x10G is going to require more balls, more serdes, and bigger package due to power. As we move to 4x25G we should see cost savings there and this can be quantified in a relative manner.

What we do *NOT* do, is look at the "cost" of modules on the street and use that as the basis for cost comparisons. At that point, you are not talking about "cost". I think we should also avoid relating costs of silicon, system, etc to any particular think like media cost. If we do that, we violate the "bananas" argument which essentially says that creating anything that can be related back to dollar value is inappropriate.

Dan

On 2/3/12 9:09 AM, Ali Ghiasi wrote:
Paul/Dan

My concern by using 100Gbase-SR10 which is high cost we are creating too low a bar.  The situation is even 
worse if you look at 100G-LR4 with its astronomical cost!

I prefer still for any cost comparison to go to 10Gbase-SR/LR something were its cost close to earth than moon.

Thanks,
Ali


On Feb 3, 2012, at 6:03 AM, Kolesar, Paul wrote:

All,

I struggled with the cost basis question while I prepared my contribution to the just-past meeting.  I considered using either 10GBASE-SR or 100GBASE-SR10 as the basis.  In reviewing contributions on transceivers (a.k.a. PMDs) I noticed that there was a tendency to use 100GBASE-SR10.  So to make it straight forward I decided to also use 100GBASE-SR10 as the cost basis for the cabling cost analysis portion of the Solution Set Analyzer called “Kolesar Kalculator 2012_01_25” in the tools folder on our web site.  This spreadsheet analysis tool allows one to get a complete channel cost analysis that includes the transceiver modules and the cabling that connects them.  See

http://grouper.ieee.org/groups/802/3/100GNGOPTX/public/tools/index.html

 

Therefore, to use this tool to get a complete cost comparison, the cost basis comparison of transceiver modules must also be entered relative to 100GBASE-SR10. 

 

I offer this tool as a means to get various cost projections on the same playing field.  My rationale is that using a common analysis tool will remove some of the variability factors that cloud the cost picture. This should allow us to make more confident and less contentious decisions regarding reach objectives that often contain significant consideration of the trade-off between reach and cost. 

 

The analysis that I included at the end of my user’s-guide contribution “Solution Set Analyzer Update (revised)”

http://grouper.ieee.org/groups/802/3/100GNGOPTX/public/jan12/kolesar_01a_0112_NG100GOPTX.pdf

 

indicates that the optimal reach objective for a possible future 100GBASE-SR4 is heavily dependent on the cost of the single-mode transceivers that will be needed to satisfy channel lengths that exceed -SR4 capability.  I stressed this point at the conclusion of my presentation, and I bring it up here again, because the structure of the ad-hocs mentioned by Dan compartmentalizes and separates the MM from the SM studies.  While this seems like a natural and traditional organization structure, and there is overlap among those involved, I would like all involved to keep this fact in mind:  These are not independent silos.  They are highly interdependent parts of the whole data center ecosystem and must be treated that way in order to arrive at an optimal solution set. 

 

So I encourage folks in both ad-hocs to apply the Solution Set Analyzer to sets of PMDs (both MM and SM) that are needed to provide complete data center channel coverage.  With sufficient cross-pollination between the ad-hocs, each should be able to keep informed of the other’s relevant contributions in a timely way. 

 

Regards,

Paul

 


From: Daniel Dove [mailto:ddove@xxxxxxx]
Sent: Thursday, February 02, 2012 10:41 PM
To: STDS-802-3-100GNGOPTX@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3_100GNGOPTX] Minutes Uploaded - Forward Direction

 

Hi Ali,

I don't think the 10x vs 3x model applies to new PMDs for a given speed.

What is important is that we believe we can achieve Broad Market Potential, Economic Feasibility, and Technical Feasibility for any particular objective we produce. (assuming distinct identity and compatibility are met)

First, we need to convince ourselves of this. Then, we need to convince 802.3 and the SEC.

Dan

On 2/2/12 8:33 PM, Ali Ghiasi wrote:

Dan

 

We can go with 100GBase-SR10 cost if its cost has reach traditional Ethernet cost which is 10x BW 3X the cost.

Otherwise it would be better to go back to the basic  100G-SR4 should be 3x the cost of 10GBase-SR

and the new SMF PMD should be 3x the cost of 10Gbase-LR.

 

I expect both 100Gbase-SR10 and 100Gbase-LR4 would fail above criteria!

 

Thanks,

Ali

 

On Feb 2, 2012, at 4:49 PM, Daniel Dove wrote:



Participants,

I should mention that my suggestion below to use 100GBASE-SR10 for relative cost is not mandatory. It was a suggestion and should be considered as one possible approach to relative cost assessment for SR4.

For an SMF objective, the ad hoc should decide what it wishes to use for relative cost assessment if anything.

In theory, having a common point for relative cost assessment is not required. Each presenter can provide their best judgment, explain how they came to it, and let the group determine whether they are accurate. This approach is also acceptable.

Regards,

Dan Dove



On 2/2/12 2:43 PM, Daniel Dove wrote:

Dear Study Group Participants,

The draft minutes have been uploaded to our website at http://www.ieee802.org/3/100GNGOPTX/public/index.html. Please take a moment to review and feedback any items to Kapil Shrikhande our vice-chair.

For those who attended the Study Group meeting in Newport Beach, you are aware that we ended without a wrap-up due to a call for adjournment, second and lacking opposition, we adjourned. At the time, I felt it would be better to gather our thoughts and focus on how to move forward.

For those who did not attend, we were able to secure another objective, "
Define re-timed 4-lane 100G PMA to PMA electrical interfaces for chip to chip and chip to module applications". In addition, we saw many presentations related to study for MMF and SMF objectives.

We ran a few straw-polls and essentially the outcome was that we have additional work to come to consensus on either a SMF or MMF objective. In addition, guidance was provided through the straw-polling, but it may not have been specific to making progress as a team. Rather, it was oriented towards the type of material we would like to see. So, below I will address a proposal for making forward progress using the information gleaned from our meeting.

Adhocs:

Multi-Mode ad hoc led by Jonathan King.
Single-Mode ad hoc led by Pete Anslow.

These two groups will solicit participation and meet via teleconference to:

  1. Identify a straw-man objective that can gain consensus
  2. Identify specific media/reach, market potential related to that reach based on relative cost to SR10, technical feasibility
  3. Identify presentation material that they believe will convince the SG their objective is valid.

We need to avoid getting into "baseline proposal mode" where we see our preferred alternative competing with the other alternatives. The goal of SG presentations should not be not to sell a proposal. They should be focused on demonstrating an objective meets the 5 criteria with multiple approaches.

If these two groups can pull together a compelling set of objectives, and presentations that demonstrate they meet the 5 criteria, we can then come together in March and work to identify any remaining consensus opportunities that can be worked on for the upcoming May meeting.

Presuming we can finalize our objectives, 5 criteria responses, and get our PAR completed in May, we will be ready to pre-submit and move toward a July PAR submittal.

Best Regards,


Dan Dove
Chair, IEEE 802.3 Next Generation Optical Ethernet Study Group