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RE: [10GBASE-T] Proposed modification to PAR scope

Pat – thanks for the clarifications – I’d missed the fact that speed wasn’t mentioned (must be still suffering from Italian jet-lag).  Scopes should be broad but clear.  The CX4 scope is probably a good model.  “based on” is different than saying it must implement it.  (under this scope a 10GBASE-CX4 could incorporate other line codes, etc.)  Similarly “working over the wiring types used in structured cabling” is a bit different than the text as written, which enters into a more specific description of “structured cabling” (we had a little discussion in Italy where some had a very narrow understanding of what that means).


I’ll have to think a little about an alternative, but I think we’re on the same principle: speed & wiring types define 10GBASE-T, but the detailed description is for the objectives.



George Zimmerman

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cell: (310) 920-3860

-----Original Message-----
From: []
Sent: Wednesday, September 24, 2003 3:28 PM
George Zimmerman;;;;
Subject: RE: [10GBASE-T] Proposed modification to PAR scope




I think Dan's suggestion went too far - very specific media descriptions (like references to 11801) have always been for the objectives rather then the PAR. On the other hand, the existing scope is much more broad than previous projects:


Current scope:

The scope of this project is to specify additions to and appropriate modifications of IEEE Std 802.3 (including all approved amendments and corrigenda) to add a copper Physical Layer (PHY) specification.


Howard's suggested scope: 

Specify a Physical Layer (PHY) for operation at 10 Gb/s
   on horizontal structured copper cabling, using the existing
   Media Access Controller, and with extensions to the appropriate
   physical layer management parameters, of IEEE Std 802.3


CX4 scope:

The scope of this project is to specify additions to and appropriate modifications of IEEE Std 802.3 as amended by IEEE Std   802.3ae-2002 (and any other approved amendment or corrigendum) to add a copper Physical Medium Dependent (PMD) option for 10   Gb/s operation, building upon the existing 10GBASE-X Physical Coding Sublayer (PCS) and 10 Gigabit Attachment Unit Interface   (XAUI) specifications. 


The CX4 scope text is much more similar to Howard's suggested scope. Both have a statement about the speed. I can't recall any scope statement we have done for a PHY project that omitted mention of speed. The CX4 scope doesn't say anything about the type of copper, but it specifies that the PHY will be based on the X PCS and the XAUI specs which limits it pretty clearly. For 10GBASE-T, the intent to work over the wiring types used in structured cabling and the 10 Gbit/s speed are the defining factors.


Look at it this way. IEEE Std 802.3 already has many copper Physical Layer specifications. Therefore the job listed in the current scope statement has already been done. If the PAR is approved with the current scope, the scope will be published by the IEEE. How would a reader seeing that scope know what the project was about and whether they were interested? Howard's scope is a more clear statement of what we want to do.


If something in Howard's scope is too confining, then please propose an alternative that is reasonably descriptive of the particular nature of this project - not something that could describe 5 or more other projects we have already done.