[STDS-802-3-400G] Proposed response to comment #558

[Brad Booth <bbooth@xxxxxxxx>]

Dear Task Force members,

I'm going to be unable to attend 802.3bs on Monday and Tuesday due to some personal commitments, but I wanted an opportunity to provide my thoughts on the response to one of the comments I made against the draft.

In comment #558, I expressed my concern that 400GBASE-FR8 doesn't satisfy the broad market potential or economic feasibility requirements. The proposed response is as follows:

PROPOSED REJECT.

Based on data presented that supported the development of the responses to the Broad

Market Potential and Economic Feasibility Criteria, the Study Group and subsequently the

802.3 WG approved these responses. This data covered the solution that was eventually

adopted by the Task Force and is specified in P802.3bs Draft 2.0.

The SMF objective for 2km was adopted based on data presenting its need across multiple

applications. This need across multiple application areas is noted in the Broad Market

Potential Response in the IEEE P802.3bs CSD (https://mentor.ieee.org/802-ec/dcn/16/ec-

16-0057-00-ACSD-802-3bs.pdf). The commenter notes a specific implementation of

faceplate density (32 ports per 1 RU) as a requirement that must be satisfied. However,

the stated requirement is not supported by reference to an existing presentation or new

data that demonstrates this requirement across the different application areas that have

been noted in the Broad Market Potential Response.

Additionally, the commenter used the noted implementation for determining a power

envelope and cost requirements for the optical solutions, and then continues with

statements regarding "current power estimations." However, the commenter has not

provided any reference to an existing presentation or new data regarding the power

envelope, cost requirements, or "current power estimations" that can be considered.

 

In my humble opinion, the response is very weak. The Broad Market Potential and the Economic Feasibility text in the CSD does not propose a solution. The solution or PMD proposed must satisfy the CSD. Broad Market Potential requires that a solution:

At a minimum, address the following areas:

a) Broad sets of applicability.

b) Multiple vendors and numerous users.

c) Balanced Costs (LAN versus attached stations)

And Economic Feasibility requires:

Among the areas that may be addressed in the cost for performance

analysis are the following:

a) Balanced costs (infrastructure versus attached stations).

b) Known cost factors.

c) Consideration of installation costs.

d) Consideration of operational costs (e.g. energy consumption).

e) Other areas, as appropriate.

The 400GBASE-FR8 must be able to satisfy a market that is from 2 m to 2 km using duplex SMF. That reach and medium covers a very high number of data center installations which rely heavily (if not predominantly) on 1 RU switches with a specific port density and the ability to potentially change the pluggable modules. This market was supported by presentations given by multiple folks in both Study Group and Task Force meetings.

The response is correct that I do not provide any references to presentations for power estimates or costs. Unfortunately, I'm not in a position to release information that was shared under NDA. I do assume though that anyone "versed in the art" can perform the necessary calculations to surmise a cost and power estimate, and likewise can converse with those building or purchasing solutions that use duplex SMF for their 2 m to 2 km Ethernet connections to determine if there is a market for 400GBASE-FR8.

While I do not expect to change the response from a REJECT, I would like to encourage those in the Task Force to perform their own evaluations. If there is data someone can present that indicates that 400GBASE-FR8 can fit into a QSFP-DD or an OSFP, I would gladly welcome it. If not, then I'd encourage others to support this comment during the recirculation ballot.

Respectfully,

Brad