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I remain supportive of the objectives (50, 100, 200) we adopted in Atlanta, and hope these objectives are added to in Macau.
Coming at this from the switch / high port count ASIC perspective we try to build in maximum flexibility to our devices at the port level to offer maximum physical layer flexibility as requested by our customers - ideally based on IEEE standards.
Historically this has meant that in the 40G generation as an example, a 4 lane port could be operated at 4 x 10G, 2 x 20G (although not an IEEE standard) and 1 x 40G. Similarly for 100G 4 lane, you can offer 4 x 25G, 2 x 50G (again, not an IEEE standard) or 1 x 100G.
Following this trend, it would seem logical to me that an 8 lane 400G port would be designed to be able to get configured as 8 x 50G, 4 x 100G, 2 x 200G, or 1 x 400G – so supporting all these port speeds, per application. You could argue this is simply pattern matching, but this trend has persisted for two generations of lane speed.
I have heard the arguments on the economics of 200G vs 400G optics, but frankly the efficiency of the marketplace as well as end customer application will dictate what gets deployed. For that reason I still maintain it’s important to support 50, 100 and 200, and all have demonstrated BMP per our CFI deck, as well as other contributions.
Sorry for the incomplete email- please wait for the completed one shortly
Everybody take a deep breath.
Scott is correct about the information presented to prior meetings concerning the market for 200G and the attractive size/cost/power properties for early implementations.
I do agree that slide 13 of booth_01 goes beyond what Brad should speak too, and I would agree that it is very easy for a reader of these slides to put this in the “FUD” category. There is an unattributed statement:
(feedback received from whom? What segments of the market has Brad solicited for this feedback?)
It is extremely disrespectful to misrepresent the information being presented as anti-200G or as spreading FUD. You are certainly entitled to your opinions on 200G, so please do not be disrespectful to our thoughts and contributions to the study group.
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I wanted to comment on some of the presentations that are coming out against 200GbE in the possibly final days of the NGOATH Study Group.
As I showed in kipp_50GE_NGOATH_01_0116.pdf, 200GbE can be designed for low cost QSFP implementations from the start. This makes 200GbE applicable to the low cost / high volume switch market while 400GbE will be suited for the high cost/ low volume router market. 200GbE will be a continuation of the successful, high volume progression from 40GbE QSFP+ to 100GbE QSFP28 to 200GbE QSFP56. Highly parallel Ethernet interfaces more than 4 lanes wide like 400GbE have never reached high volume (more than 1M ports/year) and there is no reason to think this will change.
According to Dell’Oro, more 100GbE switch ports shipped than 100GbE router ports last year for the first time. This year, over 10X as many 100GbE switch ports are expected to ship than 100GbE router ports. Routers ship low volumes of high speed ports initially, but switches overwhelm routers in port shipments when the technology is ready and the cost is low enough for switching. This pattern of switching dominance is set to repeat again at 400GbE. 400GbE will ship for routers while 200GbE can come out of the gates in high volume like 40GbE.
Here’s a quick comparison of the differences between 200GbE and 400GbE:
Fits in QSFP Family of Modules
Yes, like 40GbE and 200GbE
No, requires 8 or 16 lanes
Supports Low Cost Copper
Yes, twinax and backplane
No copper here
Uses existing MMF cabling
Yes, 8 or 12 fiber MPO
No, requires new 32-fiber cabling
Supports low cost SMF modules
Yes, CWDM4 and LR4 in QSFP28
No, 8 lanes with tight wavelength spacing in higher power module
Low cost switching
In booth_50GE_NGOATH_01a_0316.pdf, the presentation claims: 200G MAC to MAC provides no value. I heard similar arguments against 40GbE in 802.3ba and 40GbE took off in switching in 2011 while 100GbE stayed high cost in routers until a 4-lane solution became available. 200GbE will add value by being lower cost/bit. No Ethernet interface has proven to be low cost when it is highly parallel (>4 lanes). Ethernet interfaces can sell millions of ports per year when they reach 4 lanes wide or less.
In nicholl_50GE_NGOATH_01_0316.pdf, the presentation claims “both a Standards and product viewpoint, 200GbE and 400GbE are likely to come out at the same time”. I agree that the standards could come out at roughly the same time, but the products will be mainly different in character than in time. High cost 400GbE will only be available in routers while low cost 200GbE will be in switches. Go to any systems vendor’s website and there will be completely separate product lines for switches and routers. Switches are for high volume and low cost while routing has very different and challenging requirements that are suited for high bandwidth deployments.
I’m glad the objectives for 200GbE are already accepted by the Study Group. I hope enough of you agree to keep 200GbE objectives in the project and prevent last minute changes with little justification beyond FUD. End users will flock to 200GbE when they see a lower cost/bit performance - just like they did for 40GbE.