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RE: [10GBASE-T] September interim meeting


I believe that everyone of us has painfully learned a lot from the history of 1000BASE-T.  We have observed the power of a single 1000BASE-T dropped from a few watts to sub-watt level today.   And we can pretty confidently assess the impact of the technology that we are gonna use in 5 years and we definitely should take that into account NOW.  

Many circuit design experts will tell you that the power of digital circuit part can be scaled down while the semiconductor technology got significant improvement in the following years (how about using 65nm when 10GB-T reach the market), but the analog circuit part won't get too much benefit from that and its performance (for example, the ADC resolution) will be limited by some fundamental physical rule.  Due to the complexity increase of the DSP part and the analog part, even using 65nm technology for digital circuit and using SiGe technology for analog circuit, to reach 100m on CAT-7, the estimated power of the transceiver (assume it is practically feasible) will be a number that can surprise you.  I believe more and more data will be given in the following meeting to show you the reality.


Bruce Tolley <>
Sent by:

07/31/2003 10:12 AM

        Subject:        RE: [10GBASE-T] September interim meeting


Thanks for providing detail on data centers. I would argue that in terms of broad market potential, 10GBASE-T would pass muster even if the only market application was data centers.

On the power issue, the first 1000BASE-T implementations did not appear until well after the standard was done, some 5 years after the High Speed Study Group got its PAR, and consumed an obscene about of power. We might have never achieved the  low power 1000BASE-T PHYs we have today if we had tried to agree on exact numbers in 1996.


At 11:00 AM 7/31/2003 -0600, wrote:


CX4 is useful especially when we have in rack connections to make or ones going to the next rack. However, the distance is too short for many other data center connects. Also, the cable for the long distance is relatively bulky which may be a problem for some uses. We will be glad to get it, but it only solves a corner of the problem space.

Something for the longer distances in data centers that is lower cost than fiber would be useful. For that environment, it doesn't necessarily have to rely on already installed wiring. Running on existing wiring is nice, but not essential.

My view of the important items for the data center environment:

It must perform solidly on the media we choose for it - data integrity factors such as BER must be met.
It must be able to live on "standard" server bus adapter formats with a TOE: e.g. PCI Express and Infiniband

which means power is a concern
It must be transparent to existing MACs - that is, the MAC must see the same behavior it sees with 10 Gig fiber.
100 m would be desireable (partly to enable future horizontal usage) but the data center could live with shaving something off that. (100 m is nice from a standards development standpoint as it saves us from arguing about what lower number is enough.)
The media it runs over should not be so stiff or bulky that it is a problem to accomodate with normal rack and data center cable management.
Of couse it must also meet EMI requirements


-----Original Message-----
From: Nariman Yousefi []
Sent: Wednesday, July 30, 2003 8:10 PM
Subject: RE: [10GBASE-T] September interim meeting


I agree that the issues you raised must be addressed by November. One of the biggest challenges for this group is to establish reality on technical feasibility on Cat7, Cat6 and Cat5e channels.  Different vendors have different conclusion on Technical feasibility. That is due to assumptions on alien cross talk mitigation techniques, impact on implementation impairments on SNR, channel model, coding gain, and analysis on chip complexity in a given process. Assumptions must be stated clearly by vendors that present technical feasibility. In this case, technical feasibility drives the broad market potential.  Technical feasibility must be addressed at least based on the following criteria:

1. Achievable distance on Class D channel with and without installation mitigation techniques.
2. Achievable distance on Class E channel with and without installation mitigation techniques.
3. Transceiver complexity in terms of estimated power dissipation and realistic targets for building blocks like ADC, PLL and etc 2-3 years from now.

We reached a conclusion that cat7 cable or class F channel has high enough capacity for 10Gbps operation.  But, can a transceiver be built with reasonable power dissipation and cost say in 90nm process or finer geometries to achieve broad market potential?

We need to keep in mind that customers have fiber and CX4 as alternatives.


At 01:08 PM 7/30/2003 -0600, wrote:
Generally, when the group can agree on clear objectives, then they can finish the rest of the work. Fuzzy objectives often indicate a lack of real concensus.
In November, I will also be expecting arguments that support the 5 criteria based on the objectives -
Broad market potential - evidence that there will be a broad market the minimum requirements of the objectives are met.
Technical feasibility - is it feasible to meet those minimum requirements
Economic feasibility - when you have met the minimum requirements will cost be suitable to make it a viable product in the markets?
In the discussions at the plenary, a power consumption issue was raised by some of the speakers.
If the broad market potential is based in part on use in devices such as end nodes (including servers in data centers), then an objective for power consumption such that this can reside in server card formats would be important. Can it fit within the power constraints of a PCI Express board and an Infiniband board (remembering that one has to allow some power for the MAC and probably TOE/RDMAP engine)?
Looking at the objectifves in agenda_1_07_03, I don't see any that address power consumption or the abilitiy to live on server card formats. In a quick search, I also didn't find any material on power consumption in the presentations that have been made to the study group. I hope that in September the group will address the issue of power.
-----Original Message-----
From: Bruce Tolley []
Sent: Monday, July 28, 2003 1:22 PM
To: Booth, Bradley;
Subject: Re: [10GBASE-T] September interim meeting


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

Nariman Yousefi
Vice President Networking Engineering

PH  (949) 585 5450
FAX (949) 453 1848
e-mail :

Bruce Tolley Senior Manager, Emerging Technologies Gigabit Systems Business Unit Cisco Systems 170 West Tasman Drive MS SJ B2 San Jose, CA 95134-1706 internet: 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