RE: PMD discussion
Chris,
I am only getting half of this conversation!!!
First of all, for the record, I believe that low cost WDM PMDs will come to
market well in advance of low-cost serial solutions.
As for optical testing, regardless of the mux/demux scheme used by a
particular vendor, the interface standard will specify a wavelength range
into which each channel must fall. It is straightforward to construct an
inline filter that will pass only one wavelength window. I assume that such
standard filters will be available as accessories to optical signal
analyzers.
-Brian Lemoff
> -----Original Message-----
> From: Chris Simoneaux [mailto:csimoneaux@xxxxxxxxxxxxx]
> Sent: Friday, June 02, 2000 12:03 AM
> To: Edward Chang; Jack Jewell; 'Ken Herrity'; '802.3ae'
> Subject: RE: PMD discussion
>
>
>
> Ed,
>
> If we are considering troubleshooting of serial vs WDM, we should also
> consider how the optical link is troubleshooted (or
> troubleshot?). This, as
> far as I can tell, is a big unknown. Especially as we are
> talking about
> potentially multiple vendors with multiple ways of optically
> mux'ing and
> demux'ing.
>
> Maybe someone can shed light on this.
>
> Chris
>
>
> -----Original Message-----
> From: Edward Chang [mailto:edward.chang@xxxxxxxxxxxxxxxx]
> Sent: Thursday, June 01, 2000 8:24 AM
> To: Jack Jewell; 'Ken Herrity'; '802.3ae'
> Subject: RE: PMD discussion
>
>
>
> Jack:
>
> All 2.125 Gbps, 4.25 Gbps, and OC48 2,5 Gbps VCSELs are
> basically the same
> GbE VCSEL technology with some modification. The Fibre
> Channel 2.125 Gbps,
> and 4.25 Gbps specifications are based on 1.0625 VCSEL
> characteristics with
> the power budget shriks inversely proportional to the data
> rate increase.
> Of course, it needs some revisions, but not a new technology
> at all. The
> WDM has been in the market for over 10, 15 years already.
> Based on the
> March OFC show, there were over 10 to 20 WDM vendors to serve
> industry.
> Users can count on the maturing WDM technologies to provide parts.
>
> I also support serial approach, which has different advantage
> from CWDM. We
> should keep working to make the advantages of each
> technologies shinning to
> serve market.
>
> For the serial PMD, the new coding scheme, 64b/66b is so
> complex, it will
> give the system people
> headache to trouble shoot a system. When the excessive error
> occurs, the
> ordinary logic analyzer will be useless to identify the cause
> of errors from
> the waveform. The 64b/66b code has too much dynamic
> features, which will
> cause difficulties in finding the cause of a problem.
>
>
>
> Regards,
>
> Edward S. Chang
> NetWorth Technologies, Inc.
> EChang@xxxxxxxxxxxxxxxx
> Tel: (610)292-2870
> Fax: (610)292-2872
>
>
>
>
>
>
>
>
>
> -----Original Message-----
> From: owner-stds-802-3-hssg@xxxxxxxx
> [mailto:owner-stds-802-3-hssg@xxxxxxxx]On Behalf Of Jack Jewell
> Sent: Wednesday, May 31, 2000 6:08 PM
> To: 'Edward Chang'; 'Ken Herrity'; '802.3ae'
> Subject: RE: PMD discussion
>
>
>
> Ed,
>
> The components you describe are NOT Gigabit Ethernet
> technologies. They are
> double speed and multiplied in number. I am well aware of
> the existance of
> 2.125 and 2.5 Gbps VCSEL products. Picolight has been making
> 2.5Gbps oxide
> VCSELs for a long time and demonstrated 2.125Gbps
> transceivers over a year
> ago. Your message addresses ICs only. Are they multiples of
> discrete ICs
> or quad versions? Either way, there is little doubt that the ICs are
> readily available. That's fine. But packaging and optics
> are the harder
> issues. They are NOT trivial and are compounded in a
> multiple-source/detector package, especially multi-wavelength
> packages. And
> the optical subassembly is still the largest cost component, even in
> single-channel Gigabit transceivers.
>
> Jack
>
>
> -----Original Message-----
> From: Edward Chang [mailto:edward.chang@xxxxxxxxxxxxxxxx]
> Sent: Wednesday, May 31, 2000 2:55 PM
> To: Jack Jewell; 'Ken Herrity'; '802.3ae'
> Subject: RE: PMD discussion
>
>
> Jack:
>
> The C/WWDM use the same technologies as the Gigabit Ethernet
> technologies.
> It is not a new technologies to bear the concerns of risks.
> The 8B/10B
> Encoder/Decoder, and SERDES at 2.0 Gbps is already in the
> market for Fibre
> Channel products, and to move up the data rate to 3.125 Gbps are just
> another revisions of the field proved technologies, but not a new
> technologies requiring test data and field tests to prove its
> feasiobility.
>
> The 850 nm VCSEL at 3.125 Gbps, basically, is the same 850
> VCSEL widely used
> in networking industry including, GbE, Fibre Channel,
> ATM...., which has
> been proved by market already.
> The 2.5 Gbps 850 VCSEL is already in the market.
>
> Those are reasons that CWDM is low cost, and will be ready for market
> introduction soon.
>
>
> Regards,
>
> Edward S. Chang
> NetWorth Technologies, Inc.
> EChang@xxxxxxxxxxxxxxxx
> Tel: (610)292-2870
> Fax: (610)292-2872
>
>
> -----Original Message-----
> From: owner-stds-802-3-hssg@xxxxxxxx
> [mailto:owner-stds-802-3-hssg@xxxxxxxx]On Behalf Of Jack Jewell
> Sent: Wednesday, May 31, 2000 2:08 PM
> To: 'Ken Herrity'; '802.3ae'
> Subject: RE: PMD discussion
>
>
>
> Ken,
>
> Sorry for the misunderstanding. The statement about 10Gig
> serial ICs stands
> alone. The last sentence regarding "broad-based support"
> refers to multiple
> companies demonstrating working links, optical subassemblies, etc. and
> providing detailed measurements to support the feasibility. In that
> context, I believe the statement is accurate.
>
> Regards,
> Jack
>
> -----Original Message-----
> From: Ken Herrity [mailto:kenh@xxxxxxxxxxx]
> Sent: Wednesday, May 31, 2000 10:34 AM
> To: '802.3ae'
> Subject: RE: PMD discussion
>
>
>
> Jack,
>
> With regards to your second point:
>
> "IC issues are nearly equal for all 3 serial approaches. But
> neither of the
> WDM solutions have anywhere near this level of broad-based support."
>
> Blaze is currently working with 10 IC companies that either
> currently have,
> will have or are planning to make chip sets to support the
> WDM solutions.
>
> Best regards,
>
> Ken
>
> -----Original Message-----
> From: owner-stds-802-3-hssg@xxxxxxxx
> [mailto:owner-stds-802-3-hssg@xxxxxxxx]On Behalf Of Jack Jewell
> Sent: Tuesday, May 30, 2000 6:14 PM
> To: '802.3ae'
> Subject: RE: PMD discussion
>
>
>
> Bruce,
>
> Your comments are well taken, though I feel compelled to
> comment on some of
> them. All in the spirit of building a clearer picture so
> that transceiver
> vendors and system vendors can make a better decision soon.
> Following your
> format:
>
> 1) Parallel solutions do not appear destined for 802.3ae
> adoption. A serial
> solution seems most suitable for this space.
>
> 2) Sooner or later everyone has to upgrade. I don't see any
> proposals to
> support 100's of meters of copper wire for 10GbE. But I
> won't try to tell
> you if this is the right time or not to recommend your
> customers to pull
> upgraded fiber. And I agree, the merits of choosing SMF for
> that upgrade
> are very strong.
> Since Picolight demonstrated a working 10Gig
> transponder at the the
> Networld & Interop tradeshow, I must disagree that "they are all
> demonstrations of upgrades to technology and products
> customers already have
> installed." No offense taken since it was a recent demo. However,
> excluding parallel solutions which are not destined for
> 802.3ae adoption, it
> is clear that the 850nm serial solution has the greatest "broad-based
> support" in terms of feasibility demonstrations of any 10GbE
> candidate PMDs.
> The serial 1310 and 1550 approaches also have a great deal of
> realness since
> they also exist in the telecom market. IC issues are nearly
> equal for all 3
> serial approaches. But neither of the WDM solutions have
> anywhere near this
> level of broad-based support.
>
> Hope you don't mind if the last comment went beyond responding to your
> email.
>
> Regards,
> Jack
>
> -----Original Message-----
> From: Bruce Tolley [mailto:btolley@xxxxxxxxx]
> Sent: Tuesday, May 30, 2000 3:58 PM
> To: Cornejo, Edward (Edward); '802.3ae'; 'Jack Jewell'
> Subject: RE: PMD discussion
>
>
> Ed:
>
> As far as I am concerned comparing 850 nm WDM with 1310 nm WDM is like
> comparing apples and oranges because they no not address the
> same customer
> segment.
>
> My customers want to run 10 GbE in the following spaces:
>
> 1) Very, very short reach for connections between switches in the same
> room. For this application,parallel solutions seem to work fine
>
> 2) Building backbone on installed 62.5 micron MM fiber. For this
> application, only one proposal works: 1310 nm WDM
> There is no threshold of pain in regard to cost, since if I
> cannot sell to
> my installed base THIS BUSINESS IS DEAD ON ARRIVAL.
>
> The 850 nm WDM PMD could cost 1/10 that of the 1310 nm part
> but that does
> me no good because the market is much smaller.
>
> Even if there were a substantial cost difference, because I
> expect cost to
> be a function of the experience curve, and the costs of the
> 1300 nm WDM to
> come down as volume ramps.
>
> And volume should ramp more quickly for a part that supports
> the installed
> base of 62..5 MM fiber. Remember, customers resist FORKLIFT
> UPGRADES. If
> you examine all the demonstrations to date of 10 gbE
> technology at trade
> shows, they are all demonstrations of upgrades to technology
> and products
> customers already have installed. This is no accident. We
> must support the
> installed base to have this market take off quickly.
>
> And by the way, if I am going to recommend new fiber for
> future proofing, I
> might as well recommend SM fiber.
>
> 3) Medium long reach ( 10 to 40 km). Several PMDs cover
> portions of this
> spectrum. 1300 nm serial seems most optimal.
>
> 4) Very long reach (over 50 km). 1550 nm serial seems the
> most optimal.
>
> Thanks for listening
>
> Bruce
>
> Bruce Tolley
> Enterprise Line of Business
> Cisco Systems
>
> At 03:25 PM 5/30/00 -0400, Cornejo, Edward (Edward) wrote:
>
> >Jack, et al,
> >
> >I could almost live with the list you have below, however, I
> thought Mr.
> >Tolley mentioned the importance of the embedded base(62.5um)
> up to 300m. If
> >this is the case, I would change the WDM from the 850 to
> 1310 window. The
> >only issue is cost between the two WDM solutions and I am
> sure there is a
> >difference, but by how much?
> >
> >Also, systems folks need to tell us what their threshold of
> pain is for
> >delta differences in cost. Is it 10%, 15%, 20% or 25%(0% is
> not an option,
> >sorry). This could make our decision easier.
> >
> >Regards,
> >Ed
> >
> >
> >
> > > ----------
> > > From: Jack Jewell[SMTP:jljewell@xxxxxxxxxxxxx]
> > > Sent: Tuesday, May 30, 2000 2:59 PM
> > > To: '802.3ae'
> > > Subject: RE: PMD discussion
> > >
> > >
> > > Walt (and others who have responded in the interim),
> > >
> > > Although I am encouraged that the group will come to some
> agreement
> > > without
> > > delaying our schedule, there is still some way to go.
> Given the breadth
> > > of
> > > the 5 objectives set forth, it seems almost certain that
> a 3-PMD set
> will
> > > leave at least one objective being greatly
> under-optimized. I would
> hate
> > > for that to be the highest volume product. Following the theme of
> > > optimizing for each space presented Thursday by Steve Haddock (and
> > > departing
> > > from his presentation of only 3 spaces), I would see the
> following as
> the
> > > optimal solutions for each Objective. Given the
> concensus that the 2km
> > > and
> > > 10km objectives are best served by a common PMD, we are really
> discussing
> > > 4
> > > distinct Objectives. Most of the debate is focused on the
> > > shorter-distance
> > > objectives, so this note focuses on them. I recommend
> the 4-PMD set
> > > below.
> > >
> > > SMF up to 40km - 1550nm Serial
> > >
> > > SMF up to 10km (incl 2km) - 1310nm Serial
> > >
> > > MMF up to 300m - 850nm Serial
> > >
> > > Installed MMF up to 100m - 850 CWDM
> > >
> > > Highest Volume Product Space
> > > The highest-volume product space here is almost certainly
> the MMF up to
> > > 300m. This is due to most of the transceivers being put into new
> products
> > > with new fibers. An interesting comment was made last Thursday
> regarding
> > > 100Mb Ethernet in which 3 PMDs were spec'd in order to
> accommodate TX
> > > grade
> > > cable as well as the installed base of T2 and T4 cable.
> Subsequently
> the
> > > T2
> > > and T4 were more or less abandoned and virtually the
> entire market went
> > > for
> > > the TX-based PMD. [I did not participate in that
> process; this is my
> > > interpretation of the comments made last Thursday. If this is
> inaccurate,
> > > I
> > > apologize.]
> > >
> > > Cost "Survey"
> > > There have been several comments today regarding costs of
> different
> PMDs.
> > > The cost comparisons which I (and Paul K) presented were
> NOT the result
> of
> > > an "unscientific survey." They are the average of
> estimates which were
> > > circulated on the reflector. No one was excluded from
> presenting their
> > > own
> > > numbers. I believe a great deal of thought was put into
> each estimate.
> > > Are
> > > the numbers accurate? Of course not. Are they all
> consistent enough to
> > > represent the general picture (which is how they were presented)?
> > > Absolutely. They have been presented publicly and
> privately with no
> > > voiced
> > > disagreement.
> > >
> > > Relative Costs of Serial and WDM
> > > It has been suggested and sometimes even stated outright
> that a WDM
> > > solution
> > > will be as low-cost or even lower-cost than a serial
> solution. This is
> > > unsupportable. I put this question to (and look for
> responses from)
> > > vendors
> > > who have manufactured and sold transceivers in any
> reasonable volume.
> > > (These are the ones who know transceiver costs better
> than anyone.)
> Does
> > > your optical subassembly cost more than your ICs? In
> expectation of a
> > > unanimous "Yes" to that question, comes the next
> question. In order to
> > > move
> > > to higher performance levels while minimizing the cost
> increase should
> > > you:
> > > 1) increase the complexity of your optics; or 2) increase
> the complexity
> > > of
> > > your ICs? This is why we aren't seriously discussing a
> WDM-only set of
> > > PMDs. WDM is a good way to get more data over a fiber
> than otherwise
> > > possible - but it's used only when simpler approaches
> cannot be used.
> As
> > > for the ICs, there were a lot of IC vendors at the meeting having
> > > aggressive
> > > goals and impressive capabilities. Assuming a "market
> entry" for 10GbE
> > > products at the end of this year, it is reasonable to
> forecast that the
> > > cost
> > > to produce a serial product will be less than its
> equivalent WDM product
> > > at
> > > the time of market entry or within 6 months after that. I.e. for
> > > essentially the entire product lifetime.
> > >
> > > The 4 PMDs recommended above are not biased in order to favor my
> company's
> > > choice of PMDs; rather my company's choice of PMDs is
> based on a hard
> view
> > > of the markets and technologies required to address them in an
> economical
> > > fashion.
> > >
> > > Jack
> > >
> > >
> > >
> > > -----Original Message-----
> > > From: Walter Thirion [mailto:wthirion@xxxxxxxxxxxx]
> > > Sent: Sunday, May 28, 2000 11:58 AM
> > > To: '802.3ae'
> > > Subject: PMD discussion
> > >
> > >
> > >
> > > First of all, thanks to everybody that presented PMD
> proposals at the
> last
> > > meeting. I've sent my presentation to David Law, so it should be
> available
> > > on the web site in the next couple of days.
> > >
> > > In listening to the discussion after my presentation and
> then going
> around
> > > and talking to people, it feels to me like we're starting
> to converge.
> Not
> > > there, yet, but making progress.
> > >
> > > The equipment manufacturers made it pretty clear they
> would like to see
> no
> > > more than 3 PMDs in the standard. The PMD vendors have
> some concern that
> > > using only 3 PMDs may sub-optimize certain objectives,
> however, they
> could
> > > support the 3 PMD position if it is made clear which 3 PMDs the
> equipment
> > > oems want.
> > >
> > > Based on an informal straw poll and anecdotal evidence,
> my opinion is
> the
> > > first choice would be the set:
> > > ________________
> > > 850 nm WWDM
> > > 1310 nm WWDM
> > > 1550 nm Serial
> > > ________________
> > >
> > > If that set isn't feasible, then the 2nd most popular choice is:
> > > ________________
> > > 850 nm WWDM
> > > 1310 nm Serial
> > > 1550 nm Serial
> > > ________________
> > >
> > > Thoughts, feedback?
> > >
> > > Walt
> > > ___________________
> > > Walter Thirion
> > > Chair, IEEE 802.3ae PMD Sub-Task Force
> > > 301 Congress Ave.
> > > Suite 2050
> > > Austin, Texas 78701
> > > Voice: 512-236-6951
> > > Fax: 512-236-6959
> > > wthirion@xxxxxxxxxxxx
> > > ___________________
> > >
>