RE: PMDs and Customer requirements
Chris:
Because I am talking with two or three potential end users of 10 GbE a
week, I disagree that my opinion represents the needs of the few. I am
talking with the real customers of 10 GbE.
In York the votes were cast on the distance objectives. For the most part
during the York voting the components and transceiver vendors voted on the
basis of what they thought their PMD solutions could do, not on the basis
of a scientific examination of the customer requirements.
Therefore it is no surprise that there is some sentiment for 5 PMDs based
on the distance objectives because the objectives themselves are based on
what people thought the PMDs could do at the time of the York meeting. .
Bruce
At 06:47 PM 5/30/00 -0600, Chris Simoneaux wrote:
>Bruce,
>
>My concern here is that we are letting the needs of the few drive the needs
>of the many...so to speak. As an equipment vendor, you must support any
>application that the customer brings to you. That's a fact we all would
>agree with. However, I disagree with basing the success of 10GbE on how
>well it supports the minority applications.
>
>Customers are typically adverse to "forklift upgrades". But in the end,
>it's a matter of economics. And the cost vs. profit of the upgrade is the
>determining factor. If most of the user's links are shorter than 100m
>(probably much shorter), then the approach to the system upgrade will
>usually be based on the short distance link and expand into the lower volume
>longer distance links, not the other way around.
>
>Embedded in this PMD selection process is the 850nm serial solution. It
>clearly offers a solution for the 300m objective. It also offers added
>value of lowest cost, simplistic interconnections for all MM fibers up to
>28m and most 50um MM fibers up to 86 meters. If technology proliferation is
>important, then 850nm serial should be a choice as it has several vendors
>that are doing actual link testing. And one that is actively demo'ing in
>the public forum. Ask that of any WDM solution. With all of it's benefits,
>why would the group not include the 850nm solution? Maybe someone can help
>me understand that.
>
>Also, I must respectfully ask for someone out there to inform me why the
>"100m over installed base", objective was chosen. Why not 50m? or 150m?
>Were there any scientific data or surveys used? Don't misinterpret, this is
>not a "knock" on the 802.3ae process. It's merely a question that's been
>bugging me for a while now.
>
>Finally, I would suggest we base our PMD solution set opinions on straw
>polls where all participants have an opportunity to vote. Informal straw
>polls can be misleading. Each subgroup within the 802.3ae seems to have an
>opinion on the PMD issue. However, we should not forget about the user
>community. The only user that stood up and voiced an opinion (that I
>remember) during the Ottawa meeting was MCI/Worldcom, and I believe they
>stood in support of 850nm serial. Correct me if I'm wrong.
>
>Chris
>
>-----Original Message-----
>From: Bruce Tolley [mailto:btolley@cisco.com]
>Sent: Tuesday, May 30, 2000 9:49 AM
>To: Walter Thirion; '802.3ae'
>Subject: PMDs and Customer requirements
>
>
>
>Walter:
>
>I have to reject the 2nd most popular set because it abandons the installed
>base of customers using their installed 62.5 nm 160 and 200 MHz*km fiber.
>
>o Buildings will not move because of 10 GbE
>
>o The cabling infrastructure will not change overnight because of 10 GbE
>
>o Customers have a requirement to run 10 GbE on the same fiber links they
>run 1 GbE today
>
>o Customers have a requirement to use 10 GbE in building backbone
>applications on their installed fiber to distances of 200 to 300 meters.
>
>There is only one PMD proposal that runs on the installed fiber at building
>backbone distances: the 4 lambda 1300 nm WWDM proposal. If we do not
>support the installed base, it will stall the market acceptance of 10
>GbE. Customers resist forklift upgrades.
>
>At the meeting in York I felt that the study group basically abandoned the
>installed base of customer by deleting the word "installed" out of the 300
>meter goal. We have to build a standard that supports the installed base
>of building backbones. There is no good reason to exclude the one proposal
>that supports this market segment.
>
>I have not hung up on the number of 3 PMDs but we have to have the one that
>supports the installed base of fiber out to 300 meters.
>
>
>Bruce Tolley
>Enterprise Line of Business
>Cisco Systems
>
>
>
>At 12:58 PM 5/28/00 -0500, Walter Thirion wrote:
>
> >First of all, thanks to everybody that presented PMD proposals at the last
> >meeting. I've sent my presentation to David Law, so it should be available
> >on the web site in the next couple of days.
> >
> >In listening to the discussion after my presentation and then going around
> >and talking to people, it feels to me like we're starting to converge. Not
> >there, yet, but making progress.
> >
> >The equipment manufacturers made it pretty clear they would like to see no
> >more than 3 PMDs in the standard. The PMD vendors have some concern that
> >using only 3 PMDs may sub-optimize certain objectives, however, they could
> >support the 3 PMD position if it is made clear which 3 PMDs the equipment
> >oems want.
> >
> >Based on an informal straw poll and anecdotal evidence, my opinion is the
> >first choice would be the set:
> >________________
> >850 nm WWDM
> >1310 nm WWDM
> >1550 nm Serial
> >________________
> >
> >If that set isn't feasible, then the 2nd most popular choice is:
> >________________
> >850 nm WWDM
> >1310 nm Serial
> >1550 nm Serial
> >________________
> >
> >Thoughts, feedback?
> >
> >Walt
> >___________________
> >Walter Thirion
> >Chair, IEEE 802.3ae PMD Sub-Task Force
> >301 Congress Ave.
> >Suite 2050
> >Austin, Texas 78701
> >Voice: 512-236-6951
> >Fax: 512-236-6959
> >wthirion@jatotech.com
> >___________________
> >