RE: Going the distance
- To: "'rtaborek@xxxxxxxxxxxxxxxx'" <rtaborek@xxxxxxxxxxxxxxxx>, "Cornejo, Edward (Edward)" <ecornejo@xxxxxxxxxx>, HSSG <stds-802-3-hssg@xxxxxxxx>
- Subject: RE: Going the distance
- From: "Haile-Mariam, Atikem" <ahmariam@xxxxxxx>
- Date: Thu, 1 Jul 1999 16:12:12 -0400
- Sender: owner-stds-802-3-hssg@xxxxxxxxxxxxxxxxxx
From the Metro data I have analyzed:
- A large majority of RBOCs/IECs have start topology-based links that are
under 5 km (mean of 3.85 km).
- As a business strategy, most CLECs are trying to collocate with
RBOCs/IECs. This means that most CLECs will also have similar link length
requirements.
- CLECs that are building rings in addition to collocation agreements have
links "clustered" around two link lengths:
- 10 km's (uni-directional)
- 20 km's (uni-directional)
Given that the mean of 3.85 km has good correlation with "tele-density"
(i.e.; where most users are); I don't think settling for 3 km's as one of
the distance objectives would pose much of a problem. (It's not ideal, but
it's a good compromise).
Additionally, 3 km "fits" with our the objective we initially set for 802.3z
and will address most - if not all - traditional LAN/enterprise
requirements....
My vote is therefore for the following SMF distance objectives for metro
grade applications:
3 km's
10 km's
20 km's
Regards
Atikem
AMP
> -----Original Message-----
> From: Rich Taborek [SMTP:rtaborek@xxxxxxxxxxxxxxxx]
> Sent: Thursday, July 01, 1999 2:40 PM
> To: Cornejo, Edward (Edward); HSSG
> Subject: Re: Going the distance
>
>
> Ed,
>
> I have no general objections to an additional 10 km and 40 km objectives
> for SMF
> for the the reasons indicated below. However, I'll reiterate Howard
> Frazier's
> advice with respect to setting distance objectives per ISO/IEC 11801:
>
> "If we adopt this objective (2-3 km for campus cabling), 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."
>
> From a Marketing perspective:
> - I have heard about significant demand for 10-15 km 10 GbE SMF links from
> many
> sources quoting fairly large volumes. I'll leave it to our surveys to
> quantify
> "large volumes"
> - I'm not so sure about the 40 km number. It sound a bit short for the
> MAN/WAN
> environment and I expect the volumes to be significantly less relative to
> 10-15
> km links. We're also playing with fire here since this is the domain of
> existing
> MAN/WAN equipment and I agree with experts like Roy Bynum and Paul
> Bottorff
> about how different the operational requirements here are than our
> familiar LAN
> environment. This objective scares me as to the supplementary requirements
> associated with the distance and how much work it will be to satisfy those
> requirements in our 10 GbE standard. Think 'delayed standard' here.
> - SMF is not a widely deployed LAN "installed base" fiber. I believe that
> this
> eliminates any installed base arguments regarding these objectives.
>
> From a Technical perspective:
> - I have absolutely no problem supporting either the 10 or 40 km
> objectives from
> a multilevel signaling perspective since this signaling is essentially
> independent of the PMD choice and can easily accommodate single optical
> laser
> required to achieve these distances, whether it be 1310 or 1550 nm. The
> proposed
> PAM5 signaling rate is only 5 GBaud to achieve 10 Gbps, thereby halving
> the
> dispersion effects at long distances.
> - For the 40 km objective more expensive (not that much more) optical
> components including optical isolators can be used here to provide a
> higher RIN,
> offsetting the effects of SNR loss due to multilevel signaling.
>
> In summary, I'm not so concerned about a 10 km SMF objective for the 10
> GbE PAR
> and would support it. I would have a more difficult time supporting the 40
> km
> solution due to all the "supplementary" issues.
>
> I would have a far more difficult time supporting any MMF objective which
> excludes ANY proposed PHY solution by requiring the support of specific
> low-bandwidth fibers at distances which only a small subset of proposed
> PHY
> solutions can support. Such an ill formed objective would certainly
> unnecessarily increase the cost of high volume 10 GbE products and would
> be a
> huge blow to the 10 GbE standards effort at this point in our process.
>
> --
>
> "Cornejo, Edward (Edward)" wrote:
>
> > I have no problem including 2km, 10km, and 40km. So I would support your
> > comments.
> >
> > Ed-Lucent
> >
> > > ----------
> > > From: Bruce_Tolley@xxxxxxxx[SMTP:Bruce_Tolley@xxxxxxxx]
> > > Sent: Thursday, July 01, 1999 1:40 PM
> > > To: Cornejo, Edward (Edward)
> > > Cc: stds-802-3-hssg@xxxxxxxx
> > > Subject: RE: Going the distance
> > >
> > >
> > >
> > > Ed:
> > >
> > > I would like to see the numbers go like this for SM fiber: 2, 10, and
> 40
> > > (if
> > > possible).
> > >
> > > Bruce
> > >
> > >
> > >
> > >
> > > "Cornejo, Edward (Edward)" <ecornejo@xxxxxxxxxx> on 07/01/99 10:36:19
> AM
> > >
> > > Sent by: "Cornejo, Edward (Edward)" <ecornejo@xxxxxxxxxx>
> > >
> > >
> > > To: stds-802-3-hssg@xxxxxxxx
> > > cc: (Bruce Tolley/HQ/3Com)
> > > Subject: RE: Going the distance
> > >
> > >
> > >
> > >
> > >
> > > Brian,
> > >
> > > It seems that HP and Lucent have a general consensus on having an
> > > objective
> > > that lists two distance requirements for single mode fiber.
> > >
> > > How does the rest of the committee feel about a 2km and 10km single
> mode
> > > fiber objectives? Is this something that has a possibility of >75%
> > > approval.
> > >
> > > Ed-Lucent
> > >
> > >
> > >
> > > > ----------
> > > > From:
> > > >
> > >
> BRIAN_LEMOFF@xxxxxxxxxxxxxxxxxxxxxxxxxx[SMTP:BRIAN_LEMOFF@HP-PaloAlto-om16
> > > > .om.hp.com]
> > > > Sent: Thursday, July 01, 1999 12:33 PM
> > > > To: Cornejo, Edward (Edward); stds-802-3-hssg@xxxxxxxx
> > > > Subject: RE: Going the distance
> > > >
> > > >
> > > > Ed,
> > > >
> > > > I don't agree that the laser is always the "big ticket item in
> a
> > > > transceiver". This may be true in long-haul telecom (and it
> may be
> > > > true for 10GbE serial), but in both 1000-SX and 1000-LX
> > > transceivers,
> > > >
> > > > the laser (i.e. VCSEL or FP) accounts for a small fraction of
> the
> > > > overall transceiver cost. It is by no means obvious that a
> serial
> > > 10G
> > > >
> > > > FP transceiver, will cost less than a 4x2.5G WWDM transceiver.
> > > > Regardless of this, I don't think it will hurt the process to
> have
> > > a
> > > > 2km objective in addition to a 10km objective.
> > > >
> > > > -Brian Lemoff
> > > > HP Labs
> > > >
> > > >
> > > > ______________________________ Reply Separator
> > > > _________________________________
> > > > Subject: RE: Going the distance
> > > > Author: Non-HP-ecornejo (ecornejo@xxxxxxxxxx) at
> HP-PaloAlto,mimegw2
> > > > Date: 7/1/99 7:33 AM
> > > >
> > > >
> > > > I believe 2km over SMF will cover a majority of Campus LAN
> applications,
> > > > and
> > > > therefore a good place to start. I base the 2km distance on FDDI
> cabling
> > > > structure, GE survey presented by Chris D., and ISO's 2-3km spec.
> > > >
> > > > The serial proposal is two fold, one for shorter reach(2km), and one
> for
> > > > intermediate reach(15km). The 2km approach uses an uncooled
> unisolated
> > > > Fabry-Perot laser; this should be considerably less cost than 4
> uncooled
> > > > unisolated DFBs(i.e. WWDM approach). I know there are other factors
> here
> > > > like packaging, and electronics, but I believe most folks would
> agree
> > > that
> > > > the laser is the biggest ticket item in a transceiver. If the
> minimum
> > > > distance is >2km, you will be excluding a potentially lower cost
> > > solution.
> > > > Unnecessarily IMHO because it covers a majority of your
> applications.
> > > >
> > > > For the same reasons I want 2km, I would not want to exclude anyone
> at
> > > the
> > > > longer distances. Therefore, I would support 2km, and 10km as the
> two
> > > > distances for SMF. Also, in my view the two distance proposals would
> be
> > > > the
> > > > same footprint and electrical interface to the PCS or MAC, so it is
> not
> > > a
> > > > major hassle having seperate laser spec's for the PMD.
> > > >
> > > > Going further distances beyond 10km, or 15km is never a problem; it
> is
> > > > just
> > > > how much customers are willing to pay.
> > > >
> > > > I concur with my colleague from HP that we should meet customer
> demands,
> > > > but
> > > > also consider technology capabilities and costs. Lets not be too
> > > exclusive
> > > > at this early juncture. It is always easier to increase our
> distances
> > > than
> > > > to throttle them back in case we run into unforseen problems with
> MMF or
> > > > SMF
> > > > at 10G.
> > > >
> > > > Ed-Lucent
> > > > > ----------
> > > > > From:
> > > > >
> > > >
> > >
> BRIAN_LEMOFF@xxxxxxxxxxxxxxxxxxxxxxxxxx[SMTP:BRIAN_LEMOFF@HP-PaloAlto-om16
> > > > > .om.hp.com]
> > > > > Sent: Wednesday, June 30, 1999 7:36 PM
> > > > > To: pbottorf@xxxxxxxxxxxxxxxxxx
> > > > > Cc: Bruce_Tolley@xxxxxxxx; hfrazier@xxxxxxxxx;
> > > > > rtaborek@xxxxxxxxxxxxxxxx; stds-802-3-hssg@xxxxxxxx
> > > > > Subject: Re: Going the distance
> > > > >
> > > > >
> > > > > 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
> > > > >
> > > >
> > >
> > >
> > >
> > >
> > >
>
> --
>
> 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
>