Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

Re: Going the distance




Bruce,

It is so that we can have one objective for campus cabling with a minimum required
support distance of 2 km.

It should be understood that this is predominantly a SMF domain.

We can then go ahead with a 10 GbE standards project and exceed these objectives
with specific optics, cable, and signaling proposals and do a credible
technical/ecomomic feasibility investigation before discarding some proposals.

Please note that the GbE objective on this issue reads:

   11. Provide a family of Physical Layer specifications which support a link
distance of:

         c. At least 3 km on single mode fiber

The GbE standard specifies 5 km, and many GbE products support 10 km. Some support
even longer distances.

Alternatively, I've heard these other numbers mentioned for SMF support for 10 GbE:

3, 5, 10, 15, 20, 40, 100 km.

Did I miss any? Are you going to get 75% agreement on any of these numbers in
Montreal?

 Some people don't like ranges as your 5 - 10 km suggests.

I say it's too early to fill in the exact supported distances for SMF. That's why I
like 2 km as an objective for campus cabling. It is also a number backed up by  a
panel of experts, ISO/IEC 11801.

- Rich

--

Bruce_Tolley@xxxxxxxx wrote:

> Rich:
>
> Would you please explain again why a goal of 5 to 10 km is not on this motion?
>
> I thought we had seen multiple comments that such a goal is technically feasible
> at reasonable cost.
>
> Bruce Tolley
> 3Com Corporation
>
> Rich Taborek <rtaborek@xxxxxxxxxxxxxxxx> on 07/01/99 02:24:05 PM
>
> Please respond to rtaborek@xxxxxxxxxxxxxxxx
>
> Sent by:  Rich Taborek <rtaborek@xxxxxxxxxxxxxxxx>
>
> To:   "Cornejo, Edward , Giles Frazier <grf@xxxxxxxxxx>, "Grow, Bob"
>       <bob.grow@xxxxxxxxx>, HSSG <stds-802-3-hssg@xxxxxxxx>
> cc:    (Bruce Tolley/HQ/3Com)
> Subject:  Re: Going the distance
>
> 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@xxxxxxxxxxxxxxxx]
> > > Reply To:     rtaborek@xxxxxxxxxxxxxxxx
> > > 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@xxxxxxxxxxxxxxxx]
> > > > Sent: Wednesday, June 30, 1999 5:15 PM
> > > > To: BRIAN_LEMOFF@xxxxxxxxxxxxxxxxxxxxxxxxxx; 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@xxxxxxxxxxxxxxxxxxxxxxxxxx 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
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > ______________________________ Reply Separator
> > > > _________________________________
> > > > > Subject: Re: Going the distance
> > > > > Author:  Non-HP-pbottorf (pbottorf@xxxxxxxxxxxxxxxxxx) at
> > > > HP-PaloAlto,mimegw2
> > > > > Date:    6/30/99 3:24 PM
> > > > >
> > > > > Bruce:
> > > > >
> > > > > I support your outlook. We already have 5-10 km with gigabit.
> > > Supporting
> > > > > these distances is necessary to support the installed base. Since the
> > > > > technology cut-off point is around 20 km and since a standard MAN
> > > distance
> > > > > is 15 km I'd prefer a slightly more aggressive objective of 15 km.
> > > This
> > > > > would still give reasonable design margin. I also believe lower cost
> > > > > technology exits below 2.5 km motivating a 2 km specification. We
> > > could
> > > > > either specify a single 15 km objective which covers all the
> > > applications
> > > > > with a higher component cost or 2 km and 15 km each with a different
> > > price
> > > > > point.
> > > > >
> > > > > I would like to see further extension into the MAN. GigE is selling
> > > day
> > > > > with reaches over 50 km. The next standard distance is 40 km. I've
> > > heard
> > > > > this distance was chosen to match the spacing of microwave towers.
> > > With
> > > > the
> > > > > 40 km distance I believe we would have all that is necessary to build
> > > > Metro
> > > > > networks.
> > > > >
> > > > > The three standard distances on SMF would be 2, 15, and 40 km. Each of
> > > > > these ranges I believe falls into a different technology with a
> > > different
> > > > > price point. If anyone has a technology which can do all three at the
> > > 2 km
> > > > > price then all the better.
> > > > >
> > > > > Paul
> > > > >
> > > > > At 09:13 AM 6/30/99 -0700, Bruce_Tolley@xxxxxxxx wrote:
> > > > > >
> > > > > >
> > > > > >
> > > > > >The point has been made before that today customers are already going
> > > 5
> > > > to
> > > > > 10 Km
> > > > > >with 1000BASE-LX.  There should be no debate that it is a market
> > > > > requirement to
> > > > > >go 5 to 10 km with 10 GbE.
> > > > > >
> > > > > >While I am willing to consider accepting  a conservative 2 to 3 km
> > > goal
> > > > as
> > > > > the
> > > > > >official goal of the project,  we need to acknowledge that this is a
> > > > > >conservative goal and, as we get on with the work of the project , we
> > > > should
> > > > > >investigate whether we can stretch this goal..
> > > > > >
> > > > > >Bruce Tolley
> > > > > >3Com Corporation
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >Rich Taborek <rtaborek@xxxxxxxxxxxxxxxx> on 06/29/99 05:01:32 PM
> > > > > >
> > > > > >Please respond to rtaborek@xxxxxxxxxxxxxxxx
> > > > > >
> > > > > >Sent by:  Rich Taborek <rtaborek@xxxxxxxxxxxxxxxx>
> > > > > >
> > > > > >
> > > > > >To:   Howard Frazier <hfrazier@xxxxxxxxx>, HSSG
> > > > <stds-802-3-hssg@xxxxxxxx>
> > > > > >cc:    (Bruce Tolley/HQ/3Com)
> > > > > >Subject:  Re: Going the distance
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >Howard,
> > > > > >
> > > > > >I will gladly accept your suggestion of removing the portion of the
> > > > > >motion in parenthesis as a  friendly amendment post-haste given your
> > > > > >support of this motion as a seconder.
> > > > > >
> > > > > >- Rich
> > > > > >
> > > > > >Howard Frazier wrote:
> > > > > >
> > > > > >> The more I think about it, the more I like the idea of adopting the
> > > > > >> 802.3z link distance objectives for 10 Gig. We should remember that
> > > > > >> we are still in the study group phase, trying to scope out a
> > > project.
> > > > > >> We can always adjust the objectives later.
> > > > > >>
> > > > > >> Let me therefore state my support for Rich's proposed motion:
> > > > > >>
> > > > > >> > "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 (applicable to copper, MMF, SMF)
> > > > > >> >
> > > > > >> > 550 m for vertical cabling: (applicable to SMF and possibly MMF)
> > > > > >> >
> > > > > >> > 2-3 km for campus cabling: (applicable to SMF)
> > > > > >>
> > > > > >> Rich, I would encourage you to drop the parenthesis.
> > > > > >>
> > > > > >> If we adopt this objective, we can make progress on the rest of the
> > > > > >> work we need to do as a study group.  As was demonstrated in
> > > 802.3z,
> > > > > >> we will need to review the objectives periodically, and revise them
> > > > > >> if there is consensus to do so.
> > > > > >>
> > > > > >> Howard Frazier
> > > > > >> Cisco Sytems, Inc.
> > > > > >
> > > > > >-------------------------------------------------------------
> > > > > >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@xxxxxxxxxxxxxxxx
> > > > > >1029 Corporation Way             http://www.transcendata.com
> > > > > >Palo Alto, CA 94303-4305    Alt email: rtaborek@xxxxxxxxxxxxx
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > Paul A. Bottorff, Director Switching Architecture
> > > > > Bay Architecture Laboratory
> > > > > Nortel Networks, Inc.
> > > > > 4401 Great America Parkway
> > > > > Santa Clara, CA 95052-8185
> > > > > Tel: 408 495 3365 Fax: 408 495 1299 ESN: 265 3365
> > > > > email: pbottorf@xxxxxxxxxxxxxxxxxx
> > > > Palo Alto, CA 94303-4305    Alt email: rtaborek@xxxxxxxxxxxxx
> > >
> > > --
> > >
> > > Best Regards,
> > > Rich

-------------------------------------------------------------
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@xxxxxxxxxxxxxxxx
1029 Corporation Way              http://www.transcendata.com
Palo Alto, CA 94303-4305    Alt email: rtaborek@xxxxxxxxxxxxx