Re: XAUI, SFF connectors
Roy,
For the edification of the reader, please pleasure us with your
distinction between a "copper etch extension contained only on the PCB"
and a "backplane". I expect that your explanation will have significant
entertainment value. XAUI was designed to support at least 20" of FR-4
PCBs. In doing this it will support operation over media including chip
metal layers, bond wires, solder balls, chip pins, pads, PCB vias,
connectors, traces, and yes, backplanes. Where to you get your material
from? You may need to hire some new writers :-)
Along with Fibre Channel and InfiniBand, Ethernet has no mature
technology at 10 Gbps yet. The only technology, I wouldn't exactly call
it mature, at 10 Gbps is SONET OC-192. This technology is sooooo
expensive that many folks came to the IEEE 802.3 Call for Interest for
10 Gigabit Ethernet in March, 1999 in Austin to see if 802.3 could
somehow reduce the cost of their prohibitively expensive technology. By
a vote of 113 to ZERO in La Jolla earlier this month, IEEE 802.3 voters
unanimously approved the XAUI baseline proposal as the way to provide
cost effective, technically simple and straightforward transport for 10
Gbps over 4 serial lanes. XAUI is applicable only to PCB traces (and
backplanes). However, the PCS and PMA components of the XGXS associated
with XAUI are identical and support 10 Gbps transport across fiber optic
cables as well. It is clear that XAUI has broad market potential within
802.3. Further significant economic benefit to the Ethernet user
community will come from the exploitation of basic XAUI technology for
Fibre Channel, InfiniBand, and general purpose backplane applications.
IEEE 802.3 and 802 has a well proven track record in developing
technologies. In fact, I consider 802.3 to be the Tiger Woods of the
standards world. This is one reason that I put tremendous personal
effort into IEEE 802.3 and have done so since initially introducing
Fibre Channel technology into the same organization in 1995. In fact,
XAUI is exactly 4X the number of lanes and 2.5X the speed of the
corresponding 1000BASE-X interface and employs the same coding. This
gives us a 10X speed increase in the simplest and most straightforward
manner possible. This is one explanation for the 113 to zip voting
result.
I don't understand how you can make the statement: "I also find it
uncomfortable and insecure to attempt to depend on a technology that
does not have a development and maturation history."
Let me ask you a question: Do you have the problem with Gigabit
Ethernet?
I think you need to find a different target than XAUI. XAUI is too easy
to defend and this thread is probably a waste of most readers' time.
Best Regards,
Rich
--
Roy Bynum wrote:
>
> Ali,
>
> You may have it backwards. XAUI is not presented as a back plane
> technology. XAUI is presented as a copper etch extension contained only on
> the PCB.
>
> The people that would be benefiting from the technology sharing is Fibre
> Channel and Infiniband. At present, those groups do not have any mature
> technology at 10Gb. Have you not noticed the reflector traffic discussing
> how this technology should be developed. If Fibre Channel and Infiniband
> had demonstrated 10Gb parallel interfaces already, then it would be a
> different situation. The original presentations on "Hari" and then "XAUI"
> would have been very different; they would have referenced previous
> implementations. If it were mature technology from the other environments,
> then the questions of "striping" and "jitter" would have been answered
> already and not be topics of discussion here. The fact that these are
> topics of discussion is another proof that it is P802.3ae that is paying
> for this and the other technologies are the actual beneficiaries.
>
> It will be P802.3ae that will be paying for the technology development and
> go through the "growing pains" to mature the technology. As a customer, I
> find paying for the development of a technology specific for other markets
> to be difficult to accept in order to get the technology that I do want and
> am willing to pay for. I also find it uncomfortable and insecure to
> attempt to depend on a technology that does not have a development and
> maturation history.
>
> Thank you,
> Roy Bynum
>
> At 09:03 AM 7/26/00 -0700, ghiasi wrote:
>
> >Hi Roy
> >
> > > X-Sender: rabynum@pop.mindspring.com
> > > Date: Mon, 24 Jul 2000 14:26:27 -0500
> > > To: ghiasi <Ali.Ghiasi@eng.sun.com>
> > > From: Roy Bynum <rabynum@mindspring.com>
> > > Subject: Re: XAUI, SFF connectors
> > > Mime-Version: 1.0
> > >
> > > Ali,
> > >
> > > I agree, it should be possible to put more than one 10GbE port on a PCI
> > > form factor. I agree, XAUI is a good technology to get from the backplane
> > > to the ASIC.
> >
> >How do you expect 10Gig Ethernet data is getting from ASIC through
> >backplane and to the I/O?
> >
> > >What I object to is hijacking the Ethernet standard to
> > >develop technology that is not for Ethernet, but for generic system
> > >vendors using Infeneband and Fibre Channel.
> >
> >Gigabit Ethernet physical layer was based on Fiber Channel, it is called
> >leveraging or cost amortization. Also Infeneband is written as
> >"Infiniband".
> >
> > >If possible, I am going to make the
> > >XAUI people pay for their pushing the cost of that technology development
> > >into the P802.3ae standard.
> >
> >Since we are going to save you some buck, I hope you don't mind instead
> >you paying us.
> >
> >Thanks,
> >
> >Ali Ghiasi
> >Sun Microsystems
> >
> > >
> > > Thank you,
> > > Roy Bynum
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Richard Taborek Sr. Phone: 408-845-6102
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