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Re: 850 nm solutions




Rich,

As you remind us, short haul copper 10Gbs was voted down as a PHY for P802.3ae.  I also noticed that you included XAUI with Hari.
Does this mean that you acknowledge that XAUI is actually another form of Hari?  Since Hari could not get a 75% supporting vote,
does this mean that you recognize XAUI at that time, in its original form, could not have gotten a 75% favorable vote?  The
technology hasn't changed.  The customer base hasn't changed.  The objectives haven't changed.  If nothing has changed, then XAUI
should not get 75% favorable vote now.  Thank you for acknowledging that Hari/XAUI has already failed to meet the 75% voting
requirement once, and could well have failed again in March, if it had been allowed to go to vote.

Thank you,
Roy Bynum



----- Original Message -----
From: Rich Taborek <rtaborek@xxxxxxxxxxxxx>
To: <stds-802-3-hssg@xxxxxxxx>
Sent: Wednesday, April 26, 2000 2:29 PM
Subject: Re: 850 nm solutions


>
> All,
>
> This note is along the same lines as Ms. Pat Thaler and Mr. Rick Walker's
> comments regarding the suitability and economic benefit of providing a short
> (e.g. to ~20 meters) coax-based copper solution at 10 Gbps.
>
> At it's April meetings in San Diego, the Fibre Channel Copper Working Group
> approved a work item to document a Hari/XAUI coax-based copper PMD for it's
> approved 10 Gigabit Fibre Channel project. The specific 10 GFC objective calls
> for a 15 meter support distance. A call for proposals is outstanding. The T11.2
> Copper Working Group will next meet in Boise, ID on June 6, 2000.
>
> I understand fully that this same solution has been voted down by the IEEE 802.3
> HSSG and I am NOT trying to dredge it up again. The purpose of this note is
> simply to present related industry activities for short-haul 10 Gbps
> interconnects.
>
> Best Regards,
> Rich
>
> --
>
> "THALER,PAT (A-Roseville,ex1)" wrote:
> >
> > Infiniband will be using something very similar to the HARI interface over
> > short copper links though the distance goal is, I think, 6 m. To travel over
> > short copper cables, it may make sense to use a 4 wide signal from HARI
> > rather than 10 Gbit/s serial.
> >
> > -----Original Message-----
> > From: Rick Walker [mailto:walker@xxxxxxxxxxxxxxxxx]
> > Sent: Wednesday, April 19, 2000 4:58 PM
> > To: stds-802-3-hssg@xxxxxxxx
> > Subject: Re: 850 nm solutions
> >
> > > Jim Tatum writes:
> > > But why does it matter? Why limit the users? Why not put in the table. It
> > > costs nothing.  Just put in what the model and data tell us to.  It is
> > > my opinion that a large percentage of 10GB style links are going to be
> > > very short, less than 10m.  If you look at the way many fiber ports
> > > are being used today, many are in the 10m range.  Also, since copper
> > > cables are going to be EXTREMELY challanged to go that distance at
> > > 10GB, why not let the market choose the lowest cost solution using
> > > 850nm VCSELs and 62.5um fiber?
> >
> > FWIW, I agree that 10G across CAT-6 or other twisted pair would be very
> > difficult.  However 10G across coaxial cable is fairly easy.  It can be
> > done with 0.1" diameter coaxial cable using simple NRZ data encoding.  A
> > simple FIR pre-equalizer can double this distance.  Without a doubt
> > copper would be the cheapest solution for links under 10M.  I would
> > estimate a mature chipset price of about $50 per end and $15 for the
> > cable.
> >
> > This performance was demonstrated in 1998 using a 25GHz bipolar chipset.
> > See: Walker, R. C., K. Hsieh, T. A. Knotts and C. Yen, "A 10Gb/s
> > Si-Bipolar TX/RX Chipset for Computer Data Transmission" , ISSCC Digest
> > of Technical Papers 41(February 1998), 302,303,450.
> >
> > A Copper PHY was voted down by the committee because it was thought that
> > there was no market for this type of low-cost short distance link.
> >
> > kind regards,
> > --
> > Rick Walker
>
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