Re: [802.3BA] Discussion on 40G for => 10 km SMF
Hi Atsushi,
> I am afraid that to chose 40GbE CWDM will ignore data center applications that is cost sensitive and may require less than 4x10G cost.
or
>"We have to resolve this to achieve <2x10G cost."
it is not clear how you derive the conclusion that 2X is needed for the data center space. Is it a gut feeling or is there a rational explanation?
At least below I attempted to articulate briefly why 4X if very reasonable on the optics (which BTW is just a part of the total system cost) to ensure market success for 40G SMF and I would like to understand if you have any specific disagreement:
"I think ~4X the cost of 10G with *just* the benefit of consolidating 4 metro fibers will work quite well.
On top of it add the operational advantage of simplifying the network by reducing the dependency on LAG by a factor of 4 and one could argue that 4X on SMF is perfectly fine."
Last I am now getting confused with this latest 2X 10G cost on top of all the cost projections presented on 40G serial:
a) http://www.ieee802.org/3/ba/public/mar08/traverso_04_0308.pdf :
2012 Serial still more than 1X CWDM
b) http://www.ieee802.org/3/ba/public/may08/jewell_02_0508.pdf:
2011 Serial is 1X CWDM
c) http://www.ieee802.org/3/ba/public/jul08/traverso_02_0708.pdf
2010 Serial is 0.78X CWDM
d) Now in 07/08 the claim is 2X 10GBASE-L which is anywhere between 0.5X and 0.3X CWDM (even lower than traverso_02_0708 in 2012)
Why the story keeps changing on serial?
Thanks,
Alessandro
> -----Original Message-----
> From: Atsushi Takai [mailto:atsushi.takai@xxxxxxxxxx]
> Sent: Monday, August 04, 2008 5:48 PM
> To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
> Subject: Re: [802.3BA] Discussion on 40G for => 10 km SMF
>
> Team
>
> First of all, in case of CWDM, volume will never resolve the issue.
> The cost will be always 4x10G+WDM.
> The cost will go down according to 10G.
>
> I agree with Chris's comment that integration will not
> resolve the cost issue in case of 40GbE CWDM.
> We also had experiences of such technologies and found difficulties.
> Thus in case of 40GbE CWDM, The cost seems 4x10G+(WDM).
>
> ((100GbE WDM is different.
> In case of 100GbE WDM, the cost will be considered almost 4x25G+(WDM).
> Thus to achieve <10x10G cost is to achieve 25G cost to be
> closer to 10G.
> We believe we can achieve it.))
>
> It seems that CWDM has no way to achieve 4x10G and may be 6x
> with reasonable estimation.
> I am afraid that to chose 40GbE CWDM will ignore data center
> applications that is cost sensitive and may require less than
> 4x10G cost.
>
> I agree that even 4x10G is much cheaper than current cost of
> 40G 2km serial.
> But it is not the discussion point.
>
> In case of serial, volume and well-known technology will
> resolve the cost issue.
> (1) Today's market is small, may be < 10K/year.
> I believe team confirmed market.
> Also carrier started to install 40Gbit/s transport
> systems recently.
> We are receiving 40Gbit/s Infiniband that is another market.
> Volume pulls the investment for the technology and it is
> happening.
> (2) Optical device companies that I discussed have no concern
> on technology.
> Especially this is 1310-nm transmission.
> (I hope you understand this is very important)
> (3) IC cost is always related volume to compensate investment.
> (4) Thus only big challenging technology is interconnection
> technology.
> We have to resolve this to achieve <2x10G cost.
> This is the interconnection between driver to Laser module
> with the length of about 1 inch or less
> that 40G signal go from driver chip to laser chip.
> We have resolution today semi-ridged coaxial cable.
> However we need low cost alternative to achieve such low cost.
> We may overcome using customized design with IC and module.
> However we need universal design to reduce cost and wide usage.
> Anyway I am optimistic for this.
>
> I believe we have to choose serial.
>
>
> =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=
> Atsushi Takai
> Marketing Division, Opnext Japan, Inc
>
> =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=
> ----- Original Message -----
> From: "Alessandro Barbieri (abarbier)" <abarbier@xxxxxxxxx>
> To: <STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx>
> Sent: Tuesday, August 05, 2008 8:00 AM
> Subject: Re: [802.3BA] Discussion on 40G for => 10 km SMF
>
>
> Hi Frank,
> I have a couple of brief of comments inline...
>
> > Steve;
> >
> > I share with your viewpoint, but still have similar concerns,
> > so put us in the category of "undecided" regarding this after
> > listening to customers from either datacom or telecom side.
> >
> > The problem is if neither 40g serial or 4x10 CWDM can provide
> > a cost trend more favorable than 4x individual 10ge, then
> > 40gbe will be hard to take off, everyone may stick to install
>
> I think ~4X the cost of 10G with *just* the benefit of
> consolidating 4 metro
> fibers will work quite well.
> On top of it add the operational advantage of simplifying the
> network by
> reducing the dependency on LAG by a factor of 4 and one could
> argue that 4X
> on SMF is perfectly fine.
>
> > 10ge a bit longer, especially for data centers (which is more
> > cost sensitive), so 40gbe SMF may eventually unable to build
> > up significant volume. Think about the 10gbe volume
> > difference regarding LX4 vs. 10ge serial.
>
> Comparing the volumes of optics destined to different
> applications is not an
> apple-to-apple comparison. Even though LX4 works on SMF, I
> believe less than
> 5% use it for that purpose.
>
> Thanks,
> Alessandro
>
>
> > 4x10g CWDM option may provide a competitive cost point from
> > day one, are we underestimating the LX4 mfg issues in terms
> > of photonics integrated circuits to drive further cost down?
> >
> > Are we too optimistic on 40g innovation for cost reduction
> > (obviously maybe lengthy and expensive development) keeping
> > in mind close to limits of current electronics?
> >
> > Feel like both 4x10g CWDM and 40ge serial face "breakthrough"
> > ahead. Without any reasonable/realistic consensus with these
> > "hard" data, seems there would be difficult for the group to
> > reach the decision unanimously.
> >
> > The likely scenarios is if both 40g serial or 4x10 CWDM
> > cannot be built more cost-effectively than 4x individual
> > 10ge, 40ge SMF will have very limited time window, then
> > people will escape it and jump straight to 100GE.
> >
> > My 1 cent.
> > Frank
> >
> > -----Original Message-----
> > From: Trowbridge, Stephen J (Steve)
> > [mailto:sjtrowbridge@xxxxxxxxxxxxxxxxxx]
> > Sent: Monday, August 04, 2008 8:50 AM
> > To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
> > Subject: Re: [802.3BA] Discussion on 40G for => 10 km SMF
> >
> > Hi Mori-san and others,
> > It goes without saying that the cost of a 40G 4x10G CWDM
> > transceiver will not over the long term fall below 4x the
> > cost of a 10G transceiver, but for a very trivial reason: Any
> > cost reduction that results from development or volumes of 40
> > GbE will also reduce the cost of a quad 10G transceiver. So
> > this is a meaningless comparison and not helpful for the
> > decision. The decision needs to be made based on how the
> > costs of 4x10G CWDM and serial 40G compare to each other, not
> > how they compare to the cost of 10G. 40G serial technology
> > has been in the market for ~6 years, and is still stubbornly
> > expensive. Costs are finally decreasing somewhat, but the gap
> > is not being closed vs. 10G because the cost of 10G is
> > decreasing even faster than the cost of 40G.
> > Regards,
> > Steve
> >
> > -----Original Message-----
> > From: Kazuyuki Mori [mailto:mori.kazuyuki-1@xxxxxxxxxxxxxx]
> > Sent: Sunday, August 03, 2008 10:21 PM
> > To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
> > Subject: Re: [802.3BA] Discussion on 40G for => 10 km SMF
> >
> > TF members,
> >
> > I'm Kazuyuki Mori, Fujitsu Labs. I support 40G Serial and I
> > basically agree with Takai-san regarding below points.
> >
> > (1) Cost
> > My understanding is that, generally speaking, the final
> > cost target for 40G optical transceiver should be 2 -3 times
> > of 10G transceivers. In order to achieve this target , I
> > again and again discussed the cost reduction approaches with
> > TOSA/ROSA suppliers, IC suppliers, optical module suppliers
> > and our laboratory experts. In case of CWDM, I haven't found
> > any technical solution to achieve this target (<x4 cost of
> > 10G transceiver), and there has been no presentations in IEEE
> > to show this cost reduction approaches until now. On the
> > other hand, 40G serial is feasible to achieve this target as
> > shown in traverso_02_0708.
> > I wonder that 40G transceiver cost will remain more than 4
> > times of 10G in future if once CWDM solution is authorized.
> >
> > (2) Size
> > I think the size reduction is another big challenging
> > target in CWDM as Chris already agreed in recent dialogues.
> > Some people say that monolithic DFB array enables high
> > density package solution, but CWDM option is almost
> > impossible to be realized because the same active layer of LD
> > cannot be applied. Also the hybrid integration using PLC with
> > an integrated AWG MUX is sometimes picked up, but it is quite
> > challenging due to high insertion loss of AWG caused by
> > intrinsic Gaussian profile, and also due to AWG temperature
> > dependence. In my perspective as a researcher, optical
> > integration approach in 40G CWDM has some intrinsic problems
> > and leads the cost increase.
> > Please remember that this isn't the case of Vcsel array,
> > but the case of DFBs and also with optical mux.
> >
> > (3) Power
> > Steve pointed out that '40G SerDes are very power hungry',
> > but this is not correct. Current SerDes is for 16:1 and 1:16,
> > however 4:1 and 1:4 SerDes
> > should be asuumed in We need to compare using 4:1 and 1:4
> > SerDes. In our
> > estimation, 2W is possible by deleting unnecessary circuits
> > from today's SerDes even when SiGe was used.
> >
> > Kazuyuki Mori
> >
> > ----- Original Message -----
> > From: "Atsushi Takai" <atsushi.takai@xxxxxxxxxx>
> > To: <STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx>
> > Sent: Sunday, August 03, 2008 12:34 PM
> > Subject: Re: [802.3BA] Discussion on 40G for => 10 km SMF
> >
> >
> > > Jeff
> > >
> > > I do not know your background.
> > > However I found, in your comment below, you misunderstood
> > the optical
> > > transmission technologies.
> > > I do not want to argue line by line.
> > >
> > > Just I would like to point one sentence:
> > > "The biggest downside of 40G serial, seems to be the
> > physics problem of
> > > PMD.".
> > > This is not true for 10km SMF.
> > > The 40Gbit/s PMD was a technical challenge in several years
> > ago but now it
> > > is not downside.
> > > Even, we are discussing 1310-nm devices while current
> > module includes
> > > 1550-nm devices.
> > > (We can neglect dispersion issue in case of 1310nm transmission)
> > >
> > > The biggest cost in current serial module is silicon chip
> > that is much
> > > more
> > > volume sensitive.
> > > I hope you know the accumulative shipment of 40Gbt/s client
> > module is
> > > around
> > > 10K peaces or such range.
> > > However IEEE confirmed market of 40GbE 10km serial enough for
> > > standardization, you can expect much lower cost with
> higher volume.
> > >
> > > Also investment for 40Gbit/s transmission networks started
> > these years,
> > > thus
> > > industry started invest for 40Gbit/s technologies.
> > > You will find much activity in the industry.
> > >
> > > All
> > >
> > > I am very concerning during the meeting and e-mail discussion,
> > > many of members may misunderstand the 40Gbit serial
> > technology status and
> > > activity in the industry,
> > > and understand only the surface.
> > > We, who has technology especially optical device
> > technology, should be
> > > responsible to let people understand the technology.
> > > I will think about it.
> > >
> > > =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=
> > > Atsushi Takai
> > > =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=
> > > ----- Original Message -----
> > > From: "Jeff Meyer" <jmeyer@xxxxxxxxx>
> > > To: <STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx>
> > > Sent: Sunday, August 03, 2008 2:33 AM
> > > Subject: Re: [802.3BA] Discussion on 40G for => 10 km SMF
> > >
> > >
> > > Chris has a excellent point about
> > >
> > > _Other Aspects_
> > >
> > > It is no longer possible to simply increase Baud to
> > match data rate,
> > > because of fundamental electrical and optical
> propagation limits.
> > > This was recognized during the 100G SMF PMD discussion,
> > with Serial
> > > never a viable alternative for the 10km or 40km reach. In the
> > > future, all data rates beyond 100G will use some form of
> > multi-lane
> > > technology. 40G is the inflection point where cost and
> > difficulty of
> > > Serial rises dramatically compared to multi-lane alternatives.
> > > Optical communication has reached the point that all
> > other forms of
> > > communication (wired or wireless) reached many years ago, where
> > > simple modulation format serial solutions are not practical.
> > >
> > >
> > > The biggest downside of 40G serial, seems to be the physics
> > problem of
> > > PMD. However there are an increasing number of long haul equipment
> > > providers who have solved this problem. There have been
> > thousands of 40G
> > > serial long haul installations deployed to date.
> > >
> > > As far as the Cost, Power, Size & Reliability I think this favors
> > > serial. The cost saving of CWDM seems largely driven by the
> > large number
> > > of vendors providing 10G IC's and components. But let us
> > ponder, if the
> > > 10GE fathers chose 4x 2.5G WDM to reduce risk in the late
> > 1990's would
> > > we be benefiting from the low costs and the large number of
> > vendors? All
> > > we need is multiple vendors of 40G serial components and
> > the prices will
> > > plummet. Lets face it the cost of SiGe is not that much
> > higher than CMOS
> > > unless you get to volumes greater than 100,000 parts. By
> then, CMOS
> > > processes will catch up to SiGe in FT. I am a microwave guy
> > and the 40G
> > > packaging is not difficult these days ( there are many
> > vendors that can
> > > do LTCC fine line packages and they are "Open Tooled" so
> > you can get a
> > > reference design for the 40G electrical packages for no
> NRE ). If we
> > > compare microwave packaging to flip chip mounting of lasers
> > and optics,
> > > I would imagine optics costs more, but I have no "hard
> > data" to support
> > > this.
> > >
> > > The biggest reason why I favor serial over CWDM is the
> > leadership for
> > > the future. Lets take the risk like the 10G serial
> > innovators did in the
> > > late 90's. Once we get several manufacturers of 40G parts
> > this prices
> > > will plummet.
> > >
> > > Schedule Risk. Albeit the risk for serial is higher but how much?
> > >
> > > Let's keep technology moving forward for the future generations.
> > >
> > >
> > >
> > > Jeff Meyer
> > >
> > >
> > >
> > > Chris Cole wrote:
> > >
> > >> Takai-san痴 7/31/08 email discusses a number of points. Our
> > arguments
> > >> concerning his first two points (Cost and Time to Market) are
> > >> unchanged from cole_04_0708, so are not repeated here. The
> > remaining
> > >> points are addressed below.
> > >>
> > >> _Power_
> > >>
> > >> The long term power consumption of 40GE CWDM and 40GE Serial is
> > >> similar. Four 10G un-cooled DFBs and associated Laser Drivers use
> > >> about the same power as one cooled 40G EML and
> associated Modulator
> > >> Driver. The remaining ICs are also about the same if
> > advanced process
> > >> nodes and new designs are assumed. As was pointed out by
> > Joel Goergen
> > >> during the Q&A session in Denver, a 40GE Serial block diagram has
> > >> comparable circuitry to 40GE CWDM block diagram when drawn
> > fairly to
> > >> permit apples to apples comparison.
> > >>
> > >> There is no basis for a claim at this late stage in the
> debate that
> > >> Serial has a power advantage over CWDM, and that CWDM
> > 菟ower reduction
> > >> plans are invisible.・In jewell_03_0508, p.9 and again in
> > >> traverso_02_0708 p. 12, ratios of power between an
> > aggressive Serial
> > >> implementation and CWDM implementation are 0.96 and 0.97,
> > i.e. clear
> > >> statements in pro-serial presentations that there is no
> advantage.
> > >>
> > >> _Size_
> > >>
> > >> For future generation products, CWDM has an advantage over
> > Serial for
> > >> fitting into a smaller form factor like QSFP because similar to a
> > >> 10GE-LR SFP+, the re-timing CDRs can be moved outside of
> > the module.
> > >> Serial always has to have the 4:1 SerDes function in the
> > module. Even
> > >> with aggressive projections about future component size
> and power,
> > >> Serial has a packaging and thermal management design
> > challenge to fit
> > >> into QSFP.
> > >>
> > >> What is required to fit 40GE CWDM into QSFP is optics
> integration.
> > >> This type of technology has been described in numerous
> > presentations
> > >> to the HSSG and involves flip-chipping lasers onto a PLC with an
> > >> integrated AWG Mux. The CWDM grid prevents use of a
> monolithic DFB
> > >> array and requires flip-chipping discrete DFBs, but that
> is a yield
> > >> and cost issue not a feasibility or size issue. The time
> > line for such
> > >> an advanced development program is lengthy, but is similar to
> > >> realistic PCB RF-interconnect 40GE Serial development
> > schedules. The
> > >> investment required to bring this advanced technology to
> market is
> > >> high, again similar to one required for low cost 40GE Serial.
> > >>
> > >> In contrast, no advanced technology development is
> > required to quickly
> > >> bring to market first generation low cost CWDM products based on
> > >> discrete optics packaged in a larger form factor.
> > >>
> > >> _Reliability_
> > >>
> > >> There is no current 1310nm 10G DFB failure data that justifies
> > >> bringing up concerns about the reliability of a 4x10G
> CWDM PMD. 10G
> > >> 1310nm PMDs ship in volume today with very high
> > reliability. If there
> > >> is actual field failure data behind this concern, it would add
> > >> credibility to have it presented.
> > >>
> > >> _Other Aspects_
> > >>
> > >> It is no longer possible to simply increase Baud to match
> > data rate,
> > >> because of fundamental electrical and optical propagation
> > limits. This
> > >> was recognized during the 100G SMF PMD discussion, with
> > Serial never a
> > >> viable alternative for the 10km or 40km reach. In the
> > future, all data
> > >> rates beyond 100G will use some form of multi-lane
> > technology. 40G is
> > >> the inflection point where cost and difficulty of Serial rises
> > >> dramatically compared to multi-lane alternatives. Optical
> > >> communication has reached the point that all other forms of
> > >> communication (wired or wireless) reached many years ago,
> > where simple
> > >> modulation format serial solutions are not practical.
> > >>
> > >> Chris
> > >>
> > >>
> > >
> >
>