Re: Distance objective
- To: BRIAN_LEMOFF@HP-PaloAlto-om16.om.hp.com, HSSG <stds-802-3-hssg@ieee.org>
- Subject: Re: Distance objective
- From: Rich Taborek <rtaborek@transcendata.com>
- Date: Thu, 01 Jul 1999 21:36:07 -0700
- Organization: Transcendata, Inc.
- References: <H00008250f06fa19@MHS>
- Reply-To: rtaborek@transcendata.com
- Sender: owner-stds-802-3-hssg@majordomo.ieee.org
Brian,
OK, now we're negotiating!
If I interpret your note correctly, you would not oppose a list consisting of
two items: 100m on MMF, 2km on SMF.
This is now very close to my ISO/IEC 11801 list excluding only the 550 m
number.
I have no problem excluding this number. However, we are a study group
investing higher speed Ethernet solutions for copper as well as fiber. I
believe that my "100 m for horizontal cabling" objective covers the copper UTP
folks adequately. Your 100m on MMF specifically excludes UTP and the 2km on SMF
certrainly doesn't help it.
What would you say if I deleted the "b. 550 m for vertical cabling" item from
my proposed motion and left "a. 100 m for horizontal cabling" and "c. 2 km for
campus cabling"? This way the objectives are still tied to ISO/IEC 11801, "a"
covers UTP and MMF, "c" covers SMF.
Best Regards,
Rich
--
BRIAN_LEMOFF@HP-PaloAlto-om16.om.hp.com wrote:
> Rich,
>
> Objective 13 in GbE was separate from the objective that explicitly
> listed fiber types and distance. This is similar to Bob Grow's
> proposal for 10GbE, i.e. one objective identical to 13 below, and the
> other to support 100m on MMF and 3km on SMF. You are confusing these
> two objectives. I will not vote for this proposal for the reasons I
> mentioned earlier. The distances and fiber types listed below seem to
> be those that have created the least number of objections, both from
> PMD vendors and system vendors.
>
> 100m on MMF
> 300m on MMF
> 2km on SMF
> 10km on SMF
> 40km on SMF
>
> Yes, this is a lengthy list, and if we want to shorten it without
> precluding viable PHY options, we can delete the longer distances,
> i.e.:
>
> 100m on MMF
> 2km on SMF
>
> I don't feel that this latter list is a particularly challenging set
> of objectives, but I'm quite confident that most would agree that the
> goals should be no less than this, and, as you have mentioned, it
> would not preclude longer-reach PMDs from the standard.
>
> Remember, 10GbE is not GbE. The physics is different and we have also
> learned some things since the GbE objectives were set out.
>
> -Brian Lemoff
> HP Labs
>
>
>
>
>
>
>
>
>
>
> Brian,
>
> Your argument about vertical and horizontal does not hold water for
> GbE that
> essentially used the same objective I'm proposing with the standard
> supporting
> distances of 220, 275, 500 and 550 m on MMF for some of its PMD
> variants. That
> objective was:
>
> 13. Support media selected from ISO/ IEC 11801
>
> Did you, or would you have have voted against that GbEobjective?
>
> - Rich
>
> --
>
> BRIAN_LEMOFF@HP-PaloAlto-om16.om.hp.com wrote:
>
> > Rich,
> >
> > As so many market surveys have indicated, the vast majority of
> MMF links,
> > including those used for vertical wiring, are 300m and below.
> Specifying
> > 100m for horizontal and 550m for vertical, rules out a PMD that
> can support
> > 300m being used for vertical cabling. I can't support this
> motion. This is
> > not a watered-down, generic motion that everyone will agree on.
> If the
> > "horizontal" and "vertical" wording were removed, or if 550m
> was changed to
> > 300m (or something less), then it would be more palatable. In
> fact, we
> > might as well go back to the original motion that was tabled in
> June which
> > listed only "100m on MMF" and "2km on SMF" as goals.
> >
> > -Brian Lemoff
> > HP Labs
> >
> > P.S. You may consider either of my suggestions as a friendly
> amendment if
> > you wish.
> >
> > ______________________________ Reply Separator
> _________________________________
> > Subject: Re: Going the distance
> > Author: Non-HP-rtaborek (rtaborek@transcendata.com) at
> HP-PaloAlto,mimegw2
> > Date: 7/1/99 2:24 PM
> >
> > Hi Ed,
> >
> > Your opinion and the same of others is exactly what I was afraid of.
> Therefore,
> > and since we're only in effect word-smithing a PROPOSED motion that
> I will make
> > at the appropriate time in Montreal. I'd like to offer the following
> rewording
> > of the motion, changing only the number 3 km to 2 km in Bob Grow's
> amendment to
> > the proposed motion. The motion would now read:
> >
> > ---------- Begin Proposed Motion ----------
> >
> > Move to adopt as an HSSG objective:
> >
> > Support premises cabling plant distances as specified in ISO/IEC
> 11801
> > a. 100 m for horizontal cabling
> > b. 550 m for vertical cabling
> > c. 2 km for campus cabling
> >
> > Mover: Rich Taborek Seconder: Howard Frazier
> >
> > ---------- End Proposed Motion ----------
> >
> > Please observe that:
> > - Howard Frazier must again second the rewording
> > - Bob Grow must accept these changes to his proposed amendment
> > - The motion addresses objectives, and not specific PMD variants
> > - A particular PHY variant, one approved for inclusion in the
> standard (if we
> > ever get a standards project underway), may specify a particular
> fiber type
> > and/or distance and/or PHY (except for fiber type) proposal.
> > - Nowhere in the motion is any distance associated with a particular
> fiber type
> > or PHY proposal
> > - Nowhere in the motion is any particular fiber type excluded.
> > - Nowhere in the motion is any particular PHY proposal excluded.
> > - Nowhere in the motion is exceeding the objectives precluded, in
> fact,
> > exceeding the objectives is encouraged.
> >
> > To the last point: We just can't seem to agree on HOW MUCH
> specifically to
> > exceed the objective. The purpose of my proposed motion is to delay
> the decision
> > of HOW MUCH until we can reasonably achieve consensus on that
> decision.
> >
> > --
> >
> > "Cornejo, Edward (Edward)" wrote:
> >
> > > Rich,
> > >
> > > I would be against 3km, and in favor of 2km because of my previous
> comments
> > > and those of Bruce LaVigne.
> > >
> > > Ed-LU
> > >
> > > > ----------
> > > > From: Rich Taborek[SMTP:rtaborek@transcendata.com]
> > > > Reply To: rtaborek@transcendata.com
> > > > Sent: Thursday, July 01, 1999 3:09 PM
> > > > To: Grow, Bob; HSSG
> > > > Subject: Re: Going the distance
> > > >
> > > >
> > > > Bob,
> > > >
> > > > I can accept your ammendment to my motion as friendly in
> general. One
> > > > specific
> > > > point is the choice of a single distance 3 km instead of 2 km.
> I'd like to
> > > > solicit comments from others as to whether this distinction (BY
> ITSELF!)
> > > > would
> > > > make the motion harder to attain 75% support. If others agree
> that the
> > > > specific
> > > > change from 2-3 km to 3 km is OK I will accept it as friendly.
> > > >
> > > > Howard?
> > > >
> > > > --
> > > >
> > > > "Grow, Bob" wrote:
> > > >
> > > > > Rich:
> > > > >
> > > > > I am in support of your compromise if with some discussion the
> Study
> > > > Group
> > > > > appears as deadlocked as the Ad Hoc is. To expedite matters,
> you should
> > > > > phrase your motion as an objective, not as guidelines for
> defining an
> > > > > objective. (We would still have to vote on the objective after
> voting on
> > > > the
> > > > > motion you outline below.) The third distance should only
> include one
> > > > > length.
> > > > >
> > > > > Move to adopt as an HSSG objective:
> > > > >
> > > > > x. Support premises cabling plant distances as specified in
> ISO/IEC
> > > > 11801
> > > > > a. 100 m for horizontal cabling
> > > > > b. 550 m for vertical cabling
> > > > > c. 3 km for campus cabling
> > > > >
> > > > > --Bob Grow
> > > > >
> > > > > -----Original Message-----
> > > > > From: Rich Taborek [mailto:rtaborek@transcendata.com]
> > > > > Sent: Wednesday, June 30, 1999 5:15 PM
> > > > > To: BRIAN_LEMOFF@HP-PaloAlto-om16.om.hp.com; HSSG
> > > > > Subject: Re: Going the distance
> > > > >
> > > > > Brian,
> > > > >
> > > > > Please keep in mind that my proposed motion to use ISO/IEC
> premises
> > > > cabling
> > > > > standards is based on our inability to overwhelmingly agree
> (75%) to
> > > > > distance
> > > > > objectives. Our best attempts at a motion failed in Coeur
> d'Alene. The
> > > > > distance ad
> > > > > hoc has reached no better consensus, and I'm afraid that
> Jonathan
> > > > Thatcher's
> > > > > proposed process is too convoluted to set clear objectives.
> I'm araid
> > > > that
> > > > > blending
> > > > > in the myriad market requirements for 10 GbE, 1 GbE
> specifications for a
> > > > > specific
> > > > > fiber type, requirements from 1 GbE links which greatly exceed
> the
> > > > standard
> > > > > and use
> > > > > non standard (enhanced) cable and/or components, and the
> capabilities of
> > > > any
> > > > > proposed 10 GbE schemes serve only to make any specific
> distance
> > > > decisions
> > > > > harder to
> > > > > make and attain the concensus of 75% of the group. Remember
> also that
> > > > we're
> > > > > a study
> > > > > group, and that you'll get your change to get your specific
> 'better'
> > > > > distance into
> > > > > the standard when we actually have a standards project to get
> it into.
> > > > >
> > > > > As an individual straw poll, would you as an individual IEEE
> voter, vote
> > > > > against the
> > > > > following motion, if made?
> > > > >
> > > > > That the distance objective support the premises cabling
> plant
> > > > distances
> > > > > as
> > > > > specified in ISO/IEC 11801
> > > > >
> > > > > The distances supported in ISO/IEC 11801 are:
> > > > >
> > > > > 100 m for horizontal cabling
> > > > > 550 m for vertical cabling
> > > > > 2-3 km for campus cabling
> > > > >
> > > > > It is assumed that the 10 GbE standard will exceed these
> objectives
> > > > quite
> > > > > handily as
> > > > > was the case for GbE.
> > > > >
> > > > > --
> > > > >
> > > > > BRIAN_LEMOFF@HP-PaloAlto-om16.om.hp.com wrote:
> > > > >
> > > > > > Paul:
> > > > > >
> > > > > > I believe that the WWDM approach that we have
> presented, when
> > > > used
> > > > > > with uncooled, unisolated, reduced spec (on SMSR,
> linearity, RIN)
> > > > > DFBs
> > > > > > will cost equal or less than the serial 10G FP laser
> approach
> > > > that
> > > > > > Lucent has proposed for 2km, and significantly less
> than the
> > > > isolated
> > > > > > DFB approach that they have proposed for 15km. This
> would
> > > > support
> > > > > > ~300m on 62.5 micron fiber, and ~10km on SMF. To push
> this
> > > > approach
> > > > > > to 15km may involve tightening the SMSR or RIN spec
> which will
> > > > > > significantly increase the cost (since much of the
> low-cost
> > > > nature of
> > > > > > the approach depends upon using low-cost DFBs).
> > > > > >
> > > > > > I realize that there is an ongoing debate about
> relative cost,
> > > > but it
> > > > > > would be a shame to set the objectives at 2km and 15km,
> when
> > > > there is
> > > > > > a potentially very low-cost solution that can go 10km.
> I have no
> > > > > > problem with a 2km and 10km objective, since I believe
> we can
> > > > satisfy
> > > > > > both with a single cost-competitive solution.
> > > > > >
> > > > > > I realize that Rich Taborek and others have criticized
> PMD
> > > > suppliers
> > > > > > (such as HP and Lucent) on this reflector for
> suggesting
> > > > objectives,
> > > > > > based on what each of our solutions can handle, but I
> don't think
> > > > we
> > > > > > can afford to ignore it either. I don't deny that I
> favor 300m
> > > > on
> > > > > > installed base MMF and 10km on SMF in large part
> because that is
> > > > what
> > > > > > our WWDM module can support. I have no problem backing
> off on
> > > > these
> > > > > > (say to 200m and 5km) if it allows alternative PMDs to
> be
> > > > considered.
> > > > > > Lucent wants 2km (not 3km) to be an objective so that
> their
> > > > serial FP
> > > > > > laser module is not excluded. I'd like 10km (and not
> 15km) for
> > > > the
> > > > > > same reason (although I believe we're still competitive
> at 2km).
> > > > > >
> > > > > > Distance objectives should reflect what the customers
> need, but
> > > > > should
> > > > > > be influenced by what the available technologies can
> achieve.
> > > > > >
> > > > > > -Brian Lemoff
> > > > > > HP Labs
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> >
-------------------------------------------------------------
Richard Taborek Sr. Tel: 650 210 8800 x101 or 408 370 9233
Principal Architect Fax: 650 940 1898 or 408 374 3645
Transcendata, Inc. Email: rtaborek@transcendata.com
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