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Re: [802SEC] Scope and CSD re-approval of the P802.3cg project


This is to complete my action item resulting from the following Conference Call item:

8.00 II Scope and CSD re-approval of the P802.3cg project -- a heads up Thompson 5 02:23 PM

Thompson gave verbal update. There was discussion regarding Thompson’s update. 

I promised to provide material on the topic in advance of the EC Meetings in Vancouver so you would be prepared for discussion there.  I asked to hold off on sending out such material until after the interim to see if any progress was made on my issues.  That meeting was held last week.  While some progress was made, things are not yet resolved.  There were proposals at the close of that meeting to make some changes in the project documentation (PAR, CSD  plus the project objectives which are internal to 802.3) but I haven't seen any proposals yet.

P802.3cg Standard for Ethernet Amendment: Physical Layer Specifications and Management Parameters for 10 Mb/s Operation and Associated Power Delivery over a Single Balanced Pair of Conductors

5.2.b. Scope of the project: Specify additions to and appropriate modifications of IEEE Std 802.3 to add 10 Mb/s Physical Layer (PHY) specifications and management parameters for operation, and associated optional provision of power, using a single balanced pair of conductors.

And, as per our 802 Operations Manual 9.2
The CSD statement shall be reviewed and approved by the WG and the Sponsor as part of the approval process for the following:
• Forwarding the PAR to NesCom
• As part of the WG ballot to assure the draft is consistent with the CSD
Forwarding the draft to Sponsor ballot
• Forwarding the draft to RevCom

It is this review for "Forwarding the draft to Sponsor ballot" that is expected to be on the EC agenda in Vancouver.
The issue: I do not feel that the draft is consistent with the project documentation (PAR, CSD  plus the project objectives which are internal to 802.3)

Thompson asserts that the addition of PLCA (what the project has labeled: Physical Layer Collision Avoidance) belongs by statements elsewhere in 802 (Ref: 5.2.3) and 802.3 (Ref: 1.1.3)  in the Media Access Control (MAC) Sublayer.  Thompson asserts that since "PLCA" provides MAC functionality, it belongs in the MAC sublayer and is thus out of scope for the approved PAR

The Task Force and text placement in the draft asserts that PLCA is in the Physical Layer and that is where it belongs (Largely, I believe, for ease of early implementation integration with existing silicon).

CSD items
There was no mention whatsoever in the PAR, CSD  or the project objectives that a new Media Access Control method would integral or even part of this project
Broad Market Potential
There is no mention of access method, old or new having an impact either way on the Broad Market Potential.  That would seem to preclude introducing a new access method without notice.
The statement "The proposed amendment will conform to the IEEE 802.3 MAC" is not true. The Ethernet MAC is only used when the new MAC doesn't preclude its operation with its new access method either by disabling it or by a fault operation. Its half-duplex shared media operation is CSMA/CA, not the CSMA/CD with which Ethernet is so closely identified.
Distinct Identity
This one is tricky.  I assert that the project is not asserting what should be its very distinct identity as something other than Ethernet.  What is in the CSD is just the usual boilerplate for Physical Layer speeds and feeds.  When the proposed network is in "PLCA" mode it has more in common with  802.4 or 802.12 than it does with Ethernet.  I believe it needs a name and a separate standard to fully leverage its distinct identity.  This is a challenge since 802.3 is the only wired group left in 802.  For this reason I think development and maintenance of the new standard should operate within 802.3.


  • Draft is modified to conform to project paperwork (this would be the case if PLCA is removed from the draft)
  • PAR & CSD are modified to describe the draft being developed 

  • >50% of the EC decides that Thompson is wrong or his opinion doesn't matter or ???
  • EC decides that this review is not procedural and removes this requirement because it is "technical"

  • No decision, stalls start of Sponsor Ballot
  • Some compromise crops up which makes things better

I have no ax to grind here about product.  I care that we follow our rules, I think they are there for a reason.  I care that Ethernet means Ethernet instead of any wired LAN. I do think that a PLCA standard should be developed with a distinct identity.

P802.3cg TF web area

Thank you,

Geoffrey O. Thompson
IEEE 802 Executive Committee
GraCaSI S.A.
Mountain View, CA 94043-5286

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