RE: (SSIG) Taking the winning route
Hi Jack
Could please clarify Ser. 850 sloution link distance of 55m. I belive this is with 62.5um
fiber. You should be able to reach 100m with 50/125 gigabit Ethernet grade.
Thanks,
Ali Ghiasi
Sun Microsystems
> From: Jack Jewell <jljewell@xxxxxxxxxxxxx>
> To: HSSG <stds-802-3-hssg@xxxxxxxx>
> Cc: "'Mike Bennett'" <mjbennett@xxxxxxx>, rtaborek@xxxxxxxxxxx
> Subject: RE: (SSIG) Taking the winning route
> Date: Wed, 12 Apr 2000 15:16:06 -0600
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>
> All,
>
> Let's clarify the difficult task of comparing different PHY costs by looking
> at the different cost components for each PHY. In the context of this
> fascinating discussion, it is worth pointing out that 802.3z also did not
> "need" the SX solution. It was included as a cost-saving solution, and it
> currently represents roughly 80% of the volume sales of GbE
> opto-Transceivers. Somehow that MUST be relevant. In the table below I've
> added the GbE SX solution to the fray. Due to space constraints in email,
> we'll have to put up with abbreviations. More explanation below.
>
> GbE-SX GbE-LX Ser.-850 WWDM Ser.-1300
>
> Laser Wavelength and Tolerance
> 1 VCSEL 1 F-P 1 VCSEL 4 DFBs 1 VCSEL/DFB
> 850+-5% 1310+-3% 850+-0.9% 1310+-0.2% 1310+-1.1%
>
> Detector (# required)
> 1 1 1 4 1
>
> Fiber Coupling
> Tx 1 MM 1 SM 1 MM 4 SM 1 SM
> Rx 1 MM 1 MM 1 MM 4 MM 1 SM
>
> Mux/Demux
> N/A N/A Elect.4:1 Opt.4:1 Elect.4:1
>
>
> Tx + Rx IC's
> 1+1 @1G 1+1 @1G 1+1 @10G 4+4 @2.5G 1+1 @10G
>
> Fiber
> Inst MM Inst SM InstMM to 55m Inst SM/MM Inst SM
>
> COST 0.5X 1.0X 1.25X 4X 2X
>
>
> The laser wavelength tolerance is included since it can become a significant
> cost issue in the 10GbE lasers, particularly for the WWDM lasers. In all
> cases, about 0.25% was deleted from the nominal wavelength tolerance due to
> temperature variations. For WWDM, of course the wavelengths are different;
> the 1310nm represents the wavelength region. Detector comparisons are
> straightforward. For fiber coupling it should be pointed out that
> single-mode (SM) coupling is more difficult on the transmit end and MM
> coupling is more difficult on the receive end. I took the WWDM Mux/Demux
> out of the optical comparison and put it into a general Mux/Demux comparison
> row. This made sense because only the WWDM needs Optical Mux/Demux and only
> the 10GbE serial solutions need Electrical Mux/Demux. For the fiber
> comparisons, "Inst" means "Installed." This should add a dash of realism
> for the final row which is the cost comparison which assumes 1.0X for the
> 1GbE-LX to keep it consistent with Rich's email.
>
> One topic of cost discussions is that of the 10Gig electronic IC's. While
> some vendors are currently charging ludicrously high prices, this is a sign
> of current lack of availability. The cost of the actual processed/packaged
> silicon is not high. For long term prediction of IC costs, put it this way.
> Who has ever bet against the scalability of Silicon - and won?
>
> Jack Jewell
>
>
>
> -----Original Message-----
> From: Mike Bennett [mailto:mjbennett@xxxxxxx]
> Sent: Saturday, April 08, 2000 5:50 PM
> To: rtaborek@xxxxxxxxxxx
> Cc: HSSG
> Subject: Re: (SSIG) Taking the winning route
>
>
>
> Rich,
>
> I should have read more carefully. Somehow I got the idea you were talking
> about High
> Bandwidth MMF. The relative cost estimate is very informative. Thanks,
>
> Mike
>
> Rich Taborek wrote:
>
> > Hi Mike,
> >
> > My comment on Serial solutions was with respect to the installed based of
> MMF,
> > which is "FDDI grade" 62.5 um MMF as I understand it. The bandwidth of
> this
> > fiber @ 850 nm is typically no more than 200 MHz*km. At 10.3125 GBaud,
> this
> > translates to roughly:
> >
> > 200 MHz*km
> > --------------- = ~39 meters (the fastest signaling rate is 1/2 the
> Baud.
> > This number is inflated since it does
> > 10.3125 GBaud/2 not consider laser rise/fall time which
> > corresponds to a higher effective signaling BW)
> >
> > Serial 850 nm solutions can easily achieve 100 m, but require new
> "enhanced"
> > MMF. This fiber does not correspond to the installed fiber base.
> >
> > Assuming that by VCSEL, you mean "serial VCSEL at 850nm" for purposes of
> cost
> > comparison, I estimate the cost differences between the various PHYs as
> (very
> > roughly):
> >
> > 1 GbE LX PHY current cost = 1
> > 10 GbE Serial VCSEL @ 850 nm in (2002) = 2-3
> > 10 GbE WWDM @ 1300 nm in (2002) = 3-4
> > 10 GbE Serial 1300 nm in (2002) = 2-4
> >
> > Best Regards,
> > Rich
> >
> > --
> >
> > Mike Bennett wrote:
> > >
> > > Hi Rich,
> > >
> > > I have a few questions for you: What distance would you say the 850nm
> serial VCSEL
> > > solution would reach? If 100m is not possible for serial VCSEL at
> 850nm, please
> > > explain why not. What would you estimate the relative cost difference
> between the VCSEL
> > > and 1300nm WWDM PHYs will be, say normalized to current LX PHYs?
> > >
> > > Respectfully,
> > >
> > > Mike Bennett
> > > Lawrence Berkely Lab
> > >
> > > Rich Taborek wrote:
> > >
> > > > Martin,
> > > >
> > > > I apologize, I should have included a bit more detail with my last
> response. I'm
> > > > currently way backed-up with reflector traffic for the week and now
> see that my
> > > > response left out some details.
> > > >
> > > > WWDM 1300nm is the only strongly supported PHY proposal which
> addresses the
> > > > intalled base of MMF.
> > > >
> > > > No Serial solutions, including the 850nm serial VCSEL solution,
> address the
> > > > installed base of MMF at reasonable distance. I peg this disatance at
> 100m as
> > > > does the corresponding distance/cable plant objective.
> > > >
> > > > The point of my previous note was that the 850nm serial VCSEL solution
> over
> > > > enhanced MMF meets only one distance/cable plant objective, whereas
> WWDM 1300nm
> > > > meets the same one plus three others, rendering it as a much more
> flexible and
> > > > encompasing solution. In simply counting objective checkmarks, it's
> 4-to-1 in
> > > > favor of WWDM.
> > > >
> > > > We all agreed to HSSG objectives. It's time to select PHY's according
> to these
> > > > objectives. I agree with Vipul's picks.
> > > >
> > > > --
> > > >
> > > > Best Regards,
> > > > Rich
> > > >
> > > >
> > > > Martin Nuss wrote:
> > > > >
> > > > > Of all the MM-fiber PMD proposals, only the 850nm serial VCSEL
> solution over the
> > > > > new high-performance fibers has so far been shown to work under
> stressed systems
> > > > > conditions, with Bit Error Rate measurements and careful analysis of
> the systems
> > > > > impairments to support that, and working with VCSELs from many
> vendors. The
> > > > > suggestions below are highly puzzling to me...
> > > > >
> > > > > Martin
> > > > >
> > > > > Rich Taborek wrote:
> > > > > >
> > > > > > Vipul, Rob,
> > > > > >
> > > > > > It should be pointed out that a Serial 850nm solution only
> partially meets one
> > > > > > HSSG distance/cable plant objective: 300m on MMF. However, this
> MMF must be the
> > > > > > new, enhanced MMF. The Serial 850nmsolution addresses no SMF
> objectives
> > > > > >
> > > > > > WWDM meets all HSSG MMF objectives as well as SMF objectives to
> 10km.
> > > > > >
> > > > > > I agree with Vipul's choice of 3 PMDs as the best possible PMD set
> to address
> > > > > > HSSG HSSG distance/cable plant objectives.
> > > > > > Best Regards,
> > > > > > Rich
> > > > > >
> > > > > > --
> > > > > >
> > > > > > Vipul Bhatt wrote:
> > > > > > >
> > > > > > > Rob,
> > > > > > >
> > > > > > > Rob Marsland wrote:
> > > > > > > >
> > > > > > > > Finally, I hate to be annoying, but this is the SERIAL sig.
> Since when is
> > > > > > > > WWDM a serial solution?
> > > > > > > >
> > > > > > >
> > > > > > > There is nothing annoying about your question. I should answer.
> I believe it
> > > > > > > is in our (the Serial SIG's) best interest to rise above our
> Serial focus and
> > > > > > > recognize that an "all Serial" set of solutions that meets all
> the distance
> > > > > > > objectives is not something our customers are willing to sign up
> for. By
> > > > > > > proposing a set of three solutions - two of which are Serial - I
> am proposing
> > > > > > > a set that has the highest chance of being accepted by our
> customers and the
> > > > > > > majority of 802.3ae members. I understand you disagree, and I
> respect your
> > > > > > > opinion.
> > > > > > >
> > > > > > > Vipul
> >
> > -------------------------------------------------------
> > Richard Taborek Sr. Phone: 408-845-6102
> > Chief Technology Officer Cell: 408-832-3957
> > nSerial Corporation Fax: 408-845-6114
> > 2500-5 Augustine Dr. mailto:rtaborek@xxxxxxxxxxx
> > Santa Clara, CA 95054 http://www.nSerial.com