Re: 850 nm solutions
Hi
I was referring to Roy Bynum but I wrote Bob.
Thanks,
Ali
>
> Hi Bob
>
> I am one of people, which has been involved in Hari, Ethernet, NGIO, and IB. Many of us have
> come to the same conclusion or the point of minimum resistance. Our goal has been to deliver
> cost competitive 10 Gig solution and absolutely not as you say "creating voting blocks".
Bob,
> I would appreciate an apology here.
>
> The big question, does it make sense for every applications to use 4 lanes of 8B/10B data to
> generate 10 gig?
> For many applications it does, allows implementation of flexible backplane and ASIC
interface.
>
> XAUI allows the development of multiple technology:
> XAUI allows the development of multiple optical technologies, at time were we don't know
which
> one is the clear winner. No body is forced to use XAUI, it is not an external interface.
>
>
> Would a serial 10 Gig using XAUI have cost advantage?
> Today most of the 10 Gig serial xcvr have a 16 bit interface. XAUI provide a flexible 2.5
gig
> interface, 8b/10b coded, jitter isolated, and capable of driving 24" without much fuss. In
> comparison your source syncournous bus allow limited PCB distance. Conversion from Hari to
> 64/66 will add about 10% to the cost of a transceiver. Compare to today 10 Gig xcvr the cost
> associated with XAUI to 64/66 chip almost could be ignored.
>
> Does XAUI Disadvantage some Applications?
> The 10 Gig E has many potential applications. Any time you are developing a technology which
> applies from 10's meters to 10's kilometers some segment of the application may not be at
> absolute lowest cost assuming same volume holds.
>
> In my view the largest cluster (~50%) of applications will be <100 m for 10 Gig E. If short
> reach segment get the burden, then it will be just DOA. Don't forget short reach provides
the
> volume, which will also reduce the cost of serial 10 Gig.
>
>
> Finally I don't believe even if you get ride of XAUI, your serial 10 Gig solution would be
any
> lower cost. You will just end up with many proprietary solutions just like right now.
>
> Thanks,
>
> Ali Ghiasi
>
> Sun Microsystems
>
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> > From: "Roy Bynum" <rabynum@xxxxxxxxxxxxxx>
> > To: "THALER,PAT (A-Roseville,ex1)" <pat_thaler@xxxxxxxxxxx>, "Rick Walker"
> <walker@xxxxxxxxxxxxxxxxx>, <stds-802-3-hssg@xxxxxxxx>
> > Subject: Re: 850 nm solutions
> > Date: Sat, 29 Apr 2000 18:05:54 -0500
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> >
> >
> > Pat,
> >
> > What I am curious about what you say is that it is "different" "groups" that came up with
> "Hari" and "XAUI", but those "groups" seem
> > to contain the same "people", and are representing the same "vendors" in the "different"
> "groups". If it is the same "people" then
> > it is effectively the same "group" in the different organizations. Technical details
aside,
> it is the massive similarities that
> > demonstrate the "commonality" and the repeated efforts to insert it into an "unrelated"
> standard. When an organization is then
> > formed that has limited closed membership with the effective purpose of creating voting
> blocks within the open organizations then
> > the process of creating "open" standards becomes skewed. As a potential customer of the
> results of the IEEE P802.3ae TF, I find
> > this disturbing.
> >
> > Thank you,
> > Roy Bynum
> >
> >
> >
> > ----- Original Message -----
> > From: THALER,PAT (A-Roseville,ex1) <pat_thaler@xxxxxxxxxxx>
> > To: Roy Bynum <rabynum@xxxxxxxxxxxxxx>; THALER,PAT (A-Roseville,ex1)
> <pat_thaler@xxxxxxxxxxx>; Rick Walker
> > <walker@xxxxxxxxxxxxxxxxx>; <stds-802-3-hssg@xxxxxxxx>
> > Sent: Friday, April 28, 2000 6:40 PM
> > Subject: RE: 850 nm solutions
> >
> >
> > > Roy,
> > >
> > > Your note seems to imply that Hari was developed within Infiniband and then
> > > introduced from
> > > there into 802.3. This is not my understanding of its history. The
> > > Infiniband group developed/
> > > is developing a 2.5 Gbaud/s serial link for use in 1-wide, 4-wide, and
> > > 12-wide configurations
> > > using the 8B/10B code. Somewhat in parallel with this, people from the Fibre
> > > Channel and
> > > Ethernet communitties got together to look at what might be good interfaces
> > > to use between
> > > physical layer chips for 10 Gbit/s implementations and came up with Hari and
> > > Sali which
> > > are roughly equivalent to the current proposals for XAUI and XGMII. These
> > > people also
> > > chose the 8B/10B code for Hari. Since one 4x2.5 Gbit'isn 8B/10B interface is
> > > pretty much
> > > like another, there is similarity between Hari and the Infiniband x4
> > > interface though
> > > there is a 25% speed difference.
> > >
> > > The interfaces were each developed by communities focused on their market's
> > > needs. In my
> > > opinion, the decision to use different speeds was driven by differences in
> > > the respective
> > > market needs.
> > >
> > > An interface at these speeds is analog. This is particularly true if it is
> > > to serve the
> > > length of traces likely to be found between transceivers and switch chips.
> > > Taking analog
> > > considerations into account when we develop the standard will enable
> > > cost-effective,
> > > robust designs. XAUI is very suitable to the use for which it has been
> > > proposed.
> > >
> > > The point of my note was: if we were going to standardize a short run copper
> > > link, it
> > > would make sense to look at what could be done on a 4-wide connection vs. a
> > > 10 Gbit
> > > serial connection. Our existing decision has been to not do a short copper
> > > link -
> > > probably driven in part by the low usage of 1000BASE-CX.
> > >
> > > Regards,
> > > Pat Thaler
> > >
> > > -----Original Message-----
> > > From: Roy Bynum [mailto:rabynum@xxxxxxxxxxxxxx]
> > > Sent: Wednesday, April 26, 2000 6:43 PM
> > > To: THALER,PAT (A-Roseville,ex1); Rick Walker; stds-802-3-hssg@xxxxxxxx
> > > Subject: Re: 850 nm solutions
> > >
> > >
> > > Pat,
> > >
> > > For Infiniband, I think that HARI is a very good solution. I question the
> > > way that it was introduced and developed as part of the
> > > effort in something that is not Infiniband. If people want to make products
> > > for Infiniband, I have no problem with that. As a
> > > customer, I question the motivations of my vendors to have me pay for the
> > > development of technology that was actually intended for
> > > another use. I wonder how much that has already increased the price of the
> > > product that I will be receiving. I wonder even more
> > > how much the vendor was actually trying to develop something for my use
> > > instead of somebody else, and gave me, the customer, the
> > > "left overs". I wonder how much better the product, that I may buy, would
> > > have been better if the vendor had not been developing
> > > technology for another use.
> > >
> > > As a customer, I was hoping to receive an 802.3 Ethernet product that
> > > treated the interface to the optical domain as a digital
> > > optical system, not an analog copper system, which you refer to for the use
> > > of HARI. As a customer I was hoping that the vendors
> > > would listen to me and my requirements and look at it as an opportunity to
> > > enter a market that is as large as the global Internet,
> > > instead of staying in the collective enterprise space. Vendors that are not
> > > looking at the market correctly have already lost their
> > > market share in the Internet backbone, and they are about to start loosing
> > > it at the access edge as well. History has shown that
> > > customers will get what they want one way or another.
> > >
> > > The response of a BIG customer,
> > > Thank you,
> > > Roy Bynum
> > >
> > >
> > >
> > >
> > > ----- Original Message -----
> > > From: THALER,PAT (A-Roseville,ex1) <pat_thaler@xxxxxxxxxxx>
> > > To: Rick Walker <walker@xxxxxxxxxxxxxxxxx>; <stds-802-3-hssg@xxxxxxxx>
> > > Sent: Wednesday, April 26, 2000 1:08 PM
> > > Subject: RE: 850 nm solutions
> > >
> > >
> > > >
> > > >
> > > > 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
> >
>