Distance objective
- TO: rtaborek@xxxxxxxxxxxxxxxx, stds-802-3-hssg@xxxxxxxx
- Subject: Distance objective
- From: BRIAN_LEMOFF@xxxxxxxxxxxxxxxxxxxxxxxxxx
- Date: Thu, 1 Jul 1999 17:34:31 -0700
- Sender: owner-stds-802-3-hssg@xxxxxxxxxxxxxxxxxx
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@xxxxxxxxxxxxxxxxxxxxxxxxxx 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@xxxxxxxxxxxxxxxx) 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@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
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
>