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RE: [10GBASE-T] PAR and 5 critters

From what I heard Thursday afternoon in IEEE 802.3 and on Friday afternoon at the Executive Committee meeting where extension of the Study Group was discussed, one thing was quite clear.  Some members will require one or more data points on rate/reach/media that demonstrate technical feasibility, economic feasibility and broad market potential.  Failure of the Study Group to do this may result in the Study Group being dissolved.  (Sterling -- a great start on focusing on some data points!)
As Rick points out, project objectives can be adjusted after a PAR is approved (and frequently are adjusted on major projects -- e.g., 802.3ah, 802.3ae, 802.3z, etc.).  The objectives though, must be well enough specified to convince IEEE 802.3 members that a PAR evaluated per the Five Criteria should be submitted to NesCom. 
I personally do not require "proof" of technical feasibility at PAR initiation.  My own threshold for comfort increases during the standard development process.   I have a fairly low confidence threshold to vote to form a SG, and the threshold increases at each successive major benchmark -- approve a PAR, authorize WG ballot and finally forward for Sponsor Ballot.  If the highest levels of confidence are to be required at the early stages of a project, then we would only write standards for shipping products.
--Bob Grow
-----Original Message-----
From: Rabinovich, Rick []
Sent: Tuesday, July 29, 2003 9:54 AM
To: 'Bruce Tolley'; Sterling Vaden
Subject: RE: [10GBASE-T] PAR and 5 critters

Sterling, Bruce,
I agree with your previous statements.
I believe that there has been enough research made by IC and cable folks to be able to define the initial 10GBASE-T objectives.
I do not believe like some attendants mentioned last Thursday that the reach objective should be fully proven before the completion of  the PAR and 5critters.
There is a very recent precedent at the P802.3ah EFM Task Force objectives which evolved specially in the copper trail as additional research and testing was done.

Rick Rabinovich
Hardware Development Director
26750 Agoura Road
Calabasas, CA 91302
Office (818)676-2476
Cell   (818)292-1401
Fax    (818)676-2716

-----Original Message-----
From: Bruce Tolley []
Sent: Tuesday, July 29, 2003 8:46 AM
To: Sterling Vaden;
Subject: Re: [10GBASE-T] PAR and 5 critters


My comments in line. This is a good start.

At 09:42 AM 7/29/2003 -0400, Sterling Vaden wrote:
OK, I'll bite,

I think it has been "shown" that for the purposes of the PAR and 5 critters, 10G will work over the following:

ISO Class F without ammendment.

[Yes I agree.]

ISO Class E (or Cat6) screened or SSTP (with extended limits to 500 or 625 MHz) extended limits TBD by ISO or TIA
(note that Class D and Class E screened (overall shield) and SSTP (individually shielded pairs) are commonly installed in Europe, so this is not a "fantasy cable". Screened cabling is also specified by TIA)


ISO Class E (or Cat6) UTP to 50 meters (with extended limits to 500 or 625 MHz) extended limits TBD by ISO or TIA

[Yes. I agree. We as IEEE 802.3 do not spec cabling but can ask ISO and TIA to work on the issue]

ISO Class D (Cat5e) Screened? Perhaps up to 80 meters, but this is grey area.

[Yes. These screened cables exist in Europe. We need to do some work to figure out the distances that can be supported.]

ISO Class D (Cat5e) UTP? Perhaps up to 40 meters,

[Yes. I think we need some minimal goal for 5E to cover some portion of the installed base]

For ISO Class D (Cat5e) there is a basic problem in that the cabling standards groups are unwilling to standardize (create limits) beyond 100 MHz, or expend further work on the cabling besides measure it. This poses a very real difficulty in specifying a protocol that relies upon performance beyond that specified by the cabling standard. (ask Geoff  Thompson) Cabling manufacturers may decide to forego warranting their cabling systems for such a protocol.
[This is a stumbling block but we do not need to solve this to go into TF. I observe that CX4 passed the hurdle of broad market potential without any support of installed structured cabling. (And I thank Shimon for this observation)}

Also, for the time being, lets pretend that alien crosstalk field testing does not exist (it doesn't). Also lets pretend that alien crosstalk mitigation techniques (all, retrofit and new cable designs) for the moment do not exist. These are considerations for the task group.
[Yes indeed but as we did with the DMD issue on MM fiber in IEEE 802.3z, sometimes IEEE 802.3 has to do some serious investigation and push the technology to be able to move forward.]
Some may also contend that the protocol will run on longer lengths of Cat5e and Cat6 UTP. If so, that is fine, but it is a matter of dispute, and therefore cannot be considered. This is also a consideration for the task group.

At the Plenary, on the last day we heard the PHY vendors backpedaling on their previously stated opiniion that it would run on Class F. If that is the case, and they insist on this position, then the project is dead. Therefore I propose that there must be an agreement that the protocol will run on at least Class F cabling to 100 meters, or we need to start over. If we can agree on that, then we can move forward to consider the other cabling classes.
[[As our chair has directed several times, people are not supposed to make claims for vendors in the meetings. But I do note that several folks who work for other, more optimistic PHY vendors still support moving forward. We have voted in a tecnical feasibility hurdle into our timeline. We should execute on that plan and schedule.]]

//Bruce Tolley

Sterling Vaden

Bruce Tolley wrote:

Thanks for the follow up.

I am confident that if we can agree on crisp, clear objectives for 10 Gbps reach and media supported in September that we can get our PAR approved and move into Task Force mode, which is where the real work begins.


At 06:35 PM 7/24/2003 -0700, Booth, Bradley wrote:

Study Group Members,

Just to let others that were not at the meeting know the outcome of the 802.3 Working Group meeting, the Study Group will have to complete its PAR, 5 Criteria and Objectives in November.  This gives the Study Group the task of completing the PAR, 5 Criteria and Objectives in 4 months.  This will make our September Interim meeting extremely important.  We will need to complete the effort as much as possible to pre-submit to the 802.3 Working Group prior to the November Plenary.  November will permit us the ability to modify the PAR, 5 Criteria and Objectives prior to asking 802.3 to put the PAR on the NesCom agenda.  The September Interim meeting will focus on the completion of our PAR, 5 Criteria and Objectives.


Chair, 10GBASE-T Study Group

Bruce Tolley
Senior Manager, Emerging Technologies
Gigabit Systems Business Unit
Cisco Systems
170 West Tasman Drive
San Jose, CA 95134-1706
ip phone: 408-526-4534

"Don't put your hiking boots in the oven unless you plan on eating them."

Colin Fletcher, The Complete Walker

Bruce Tolley
Senior Manager, Emerging Technologies
Gigabit Systems Business Unit
Cisco Systems
170 West Tasman Drive
San Jose, CA 95134-1706
ip phone: 408-526-4534

"Don't put your hiking boots in the oven unless you plan on eating them."

Colin Fletcher, The Complete Walker