Re: Short haul PMDs
Sharam,
For the record, I did propose a change to the MMF objectives. However,
the change is to add a third short-haul objective.
Furthermore, to help with the multimode PMD decision I further propose
that the 5 Criteria be considered, especially the related to cost that
the current PMD decisions seem to not take into consideration.
Best Regards,
Rich
--
"Hakimi, Sharam (Sharam)" wrote:
>
> During the past 15 years and through all of 802.3 distance Objectives, 100
> meters has been the minimum and essentially the trademark of IEEE 802.3.
> There has always been discussions that if the distance is reduced we can
> provide less expensive PHYs, but the cost difference never justified
> development of these PHYs . Providing 100 meter solutions does not prevent
> anyone from using a 10, 20, 30 or other length cables as their needs
> require. However, if time has come that the cost difference between a 100
> meter solution and something less will justify such development then we
> could look at it later, but changing the objectives at this time is a BAD
> idea in my opinion.
>
> Sharam Hakimi
>
> > ----------
> > From: Satish M.[SMTP:satish@xxxxxxxxxxxxxxxx]
> > Reply To: satish@xxxxxxxxxxxxxxxx
> > Sent: Wednesday, August 02, 2000 11:54 AM
> > To: rtaborek@xxxxxxxxxxxxx
> > Cc: HSSG
> > Subject: Re: Short haul PMDs
> >
> >
> > I am also interested in short haul solution, primarily within Data
> > centers and enterprises. My main area of interest is for ethernet
> > based SANs.
> >
> > Thanks
> >
> > Rich Taborek wrote:
> > >
> > > Ladies and Gentlemen,
> > >
> > > My best recollection of straw polls by Jonathan, our chair, was that the
> > > user community was very poorly represented at meetings. Recently, we
> > > have heard from two members of the Ethernet user community, representing
> > > very high volume Ethernet equipment users, that short haul PMDs are key.
> > >
> > > I know from others related standards bodies and industry associations
> > > representing SANs and clustered networks, sometimes referred to as
> > > System Area Networks, that the percentage of short haul links (<100 m)
> > > is significantly more than that encountered in LAN environments.
> > > Throwing typically short haul MAN/WAN access links into the fray, I'm
> > > having a hard time swallowing both the current HSSG distance/cable plant
> > > objectives and PMD solution set. This is especially true in light of a
> > > the last, but not least PAR criteria of Economic Feasibility.
> > >
> > > Ethernet users are demanding low-cost short-haul solutions. A small
> > > number of well defined and simple candidate solutions have been
> > > proposed. I suggest going with those solutions. If it takes adding a
> > > short-haul objective (<100 m) to get off the dime and allow the Task
> > > Force to further develop PMD solutions for the multimode fiber
> > > objectives, let's do it! I don't believe that the user community would
> > > settle for proprietary short haul solutions for well over half of their
> > > connections.
> > >
> > > It would help a great deal to hear from other users.
> > >
> > > Best Regards,
> > > Rich
> > >
> > > --
> > >
> > > > "McCormick, Corey" wrote:
> > > >
> > > > Our experience is still very similar. Last weekend we just cut our
> > > > last refinery from FDDI/Ethernet to GigE switches and again more than
> > > > half of the GigE ports are <25m and most of those are either 2-4m or
> > > > 10-15m. These short runs all used new cables with the correct ends so
> > > > there would be no couplers or splices. They are all SC or MT-RJ
> > > > (spec'd to get port density in the switches). The longer installed
> > > > links are 300m - 1Km and all are using 9 year old FDDI-spec fiber on
> > > > ST connectors. There are only ~10% LX and the rest are SX. We would
> > > > have used copper for the shorter links (cables that stay inside one
> > > > building and are <90M) had the cables, NICs, switch ports and GBICs
> > > > all been available at the time of the order/installation. I do not
> > > > know about others, but our short runs far outnumber long ones.
> > > >
> > > > Also it might be noted that petrochemical refineries are among the
> > > > larger manufacturing complexes in the world. They are large very
> > > > 2-dimensional installations and are usually measured in Km, not feet.
> > > > While we have some SM applications, 95+% are MM and the majority of
> > > > the ports will be hosts. I can only speculate that this will follow
> > > > as we move to 10G. Our physical architecture seems to stay about the
> > > > same regardless of the technology. Ethernet was replaced by FDDI,
> > > > which was replaced by ATM or GigE, which I believe will be replaced by
> > > > 10GE in the same pattern. As this was our last location to convert,
> > > > we have now done them all in a similar fashion and they were designed
> > > > and implemented by three different teams. (admittedly with some
> > > > cross-pollinated influence)
> > > >
> > > > Gates, Kroc, Walton all believe(d) that volume wins and I my
> > > > experience leaves me not in a position to argue. Which is better SCSI
> > > > or IDE/ATAPI? I believe SCSI to be the more scaleable, manageable and
> > > > extensible design, but ATAPI wins volume and thus cost by a huge
> > > > margin. I do not like the KISS principle sometimes, but it is more
> > > > often than not the correct one. So long as there can be modular
> > > > ports (a.k.a. GBICs), then the actual port technology matters little
> > > > to the switch/NIC vendors, but when there can be a low-cost solution
> > > > integrated everywhere, even with its limitations, I think that will be
> > > > the most successful.
> > > >
> > > > So, to improve the chances for a successful 10G implementation, it
> > > > seems to me that the short solution needs to be Good, Fast and Cheap.
> > > > The longer runs are varied in requirements and not as cost sensitive
> > > > since we need many fewer of them.
> > > >
> > > > Just more experience,
> > > >
> > > > Corey McCormick
> > > > CITGO Petroleum
> > > >
> > > > -----Original Message-----
> > > > From: Roy Bynum [mailto:rabynum@xxxxxxxxxxxxxx]
> > > > Sent: Tuesday, August 01, 2000 2:00 PM
> > > > To: Chris Simoneaux; stds-802-3-hssg@xxxxxxxx
> > > > Subject: RE: Equalization and benefits of Parallel Optics.
> > > >
> > > > Chris,
> > > >
> > > > After a lot of thought from a customer implementation viewpoint, that
> > > > is conclusion that I have come to.
> > > >
> > > > Thank you,
> > > > Roy Bynum
> > > >
> > > > At 04:29 PM 7/31/00 -0600, Chris Simoneaux wrote:
> > > >
> > > > >Roy,
> > > > >Nice piece of info. It is worthwhile to finally get an installer/end
> > > > >user perspective of the environment that 10GbE will exist in. If one
> > > > >believes your analysis (and I haven't seen any contradictions), then
> > > > >it would seem quite reasonable to expect a PMD objective which covers
> > > > >the 2~20m space.....i.e 66% of the initial market.
> > > > >
> > > > >Would you agree?
> > > > >
> > > > >Regards,
> > > > >Chris
> > --
> >
> > Satish Mali
> >
> > http://www.TrainingCity.com -> Train to success
> >
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Richard Taborek Sr. Phone: 408-845-6102
Chief Technology Officer Cell: 408-832-3957
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