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[802.3af] Fwd: Additional Comment for SC25/WG3



Dave-

Per our conversation this morning, I'm asking that the consideration of my comment be continued as there were problems with the validity of this morning's meeting as notice of the connection information was not properly distributed to the membership.

I feel that due consideration to my request was not given because of:
        1) My lack of attendance since I wasn't contacted for Call-in bridge number info
        2) Lack of attendance of others who may have wished to attend but didn't have the information.

You said that one of the reasons for turning it down was that it was submitted past the deadline. While that is true, the material was not developed until the P802.3af comment resolution meeting. The material was sent to the WG3 reflector within hours of hammering out the compromise.

You also mentioned that you were a little confused by the request. I had hoped to present the rationale in depth at the meeting this morning. As that was not possible, I will go into it a little more here (below the forwarded message).

Alan Flatman assisted in the development of this position. I anticipate his support at the meeting as an expert. I hope that he will have gathered up UK NB support also.

Please4 contact Alan or myself if you have any further questions.
Thanks for your help.

Geoff


Date: Wed, 16 Jan 2002 17:43:45 -0800
To: "ISO - JTC1/SC25/WG3 Premises Cabling" <380@xxxxxxxxxxxxxxxx>
From: "Thompson, Geoff [SC5:321:EXCH]"<gthompso@xxxxxxxxxxxxxxxxxx>
Subject: Additional Comment for SC25/WG3
Cc: 380@xxxxxxxxxxxxxxxx, <stds-802-3-pwrviamdi@xxxxxxxx>, a_flatman@xxxxxxxxxxxxxx

Dave-

I would like to ask a small favor of the TAG.
We have a quite minor comment that we would like to add to the US comments for submission against the 11801 2nd Edition Draft.

If you could approve it during the teleconference and add it to the US comments it would be of significant assistance to the work on DTE Power.

---------------------
ID              NT02 (I think) or perhaps       IEEE 01
line            1827
Clause  10.1.1
E/G/T           Editorial
Comment
With the development of DTE Power in IEEE 802.3 the status of "Mid-Span Power Insertion Equipment" is unclear as to whether it should be considered "connecting hardware" or "LAN equipment". Arguments can be made for either as it acts as one for a pair of pairs (i.e. equipment for pins 4,5/7,8) and the other for the "Ethernet pairs" (i.e. connecting hardware for pins 1,2/3,6). Those pairs pass through the mid-span box and terminate at the data transmission LAN equipment.

Inclusion in the example list of 10.1.1 will remove the uncertainty and unambiguously classify it as "equipment".

Proposed change:
Add the follow term to the list of examples on line 1827-1828:
"mid-span power insertion equipment"
The simpler term "power insertion equipment" would also be adequate.

Resolution:

----------------------------
Our expectation is that we will specify 11801 cabling from the Work Area and/or TO to the Mid-Span box. We will then provide our own test criteria for the data pair channel that extends from the Work Area through the Mid-Span box to the LAN data equipment.

This approach has consensus within the P802.3af Task Force.

Thank you very much for your help in this matter.

Best regards,

Geoff


Further explanation (2/11/01-GOT)
There are a couple of issues here.
1) At this late date, we do not want to delay the 2nd edition while study takes place on how to fit a mid-span power box into the cabling infrastructure.

2) The mid-span box has to be considered in one of 3 ways:
        (a) Application specific equipment. In this case the specified premises cabling terminates at the mid-span box. The performance of the extended channel between the mid-span box and the closet switch then is the specification responsibility of the application (This is the approach that 802.3 would prefer).
        (b) Cabling infra-structure equipment. This would require a significant body of new work in both concepts and specifications as the mid-span box would be terminating part of the channel (power pairs) at a different point than another (data pairs). Developing test procedures and specifications for this in the general case could easily become a large taks.
        (3) We could leave things unspecified as to (a) or (b) and confuse everybody. This seems like a bad idea.

3) The Mid-Span box and its associated end stations only support 10/100 Mb/s, therefore the end-to-end channel only needs "oldCat5/TIA Cat 5" performance. This is an application specific requirement.

4) The Mid-Span box inserts an additional set of connectors in the channel. This can't be done at the "newCat5/TIA Cat5e" performance level of the ISO Standard. The trick here is to use careful PC board engineering and Cat-5e connectors on the Mid-Span box to achieve adequate performance for the application.

With the application specific label we can still use the 5e permanent link but we will specify the end-to-end data channel at the old Cat5 level within the body of 802.3. The performance of this can be verified using existing tests on hand-held testers.

I would rather that this be carried into the meeting by the US TAG than submitted as an IEEE Liaison request. IT seems to me that, in terms of the ISO Standard, it is a very minor editorial request. I would like to keep it that way.

Thanks, for you help. Call if you have questions.




|================================================|
| Geoffrey O. Thompson                           |
| Chair IEEE 802.3                               |
| Nortel Networks, Inc.  M/S SC5-02              |
| 4401 Great America Parkway                     |
| P. O. Box 58185                                |
| Santa Clara, CA 95052-8185  USA                |
| Phone: +1 408 495 1339                         |
| Fax:   +1 408 495 5615                         |
| E-Mail: thompson@xxxxxxxx                      |
| Please see the IEEE 802.3 web page at          |
| http://www.ieee802.org/3/index.html
| To download your FREE copy of Std. IEEE 802.3  |
| http://standards.ieee.org/getieee802/802.3.html

|================================================|
| Geoffrey O. Thompson                           |
| Chair IEEE 802.3                               |
| Nortel Networks, Inc.  M/S SC5-02              |
| 4401 Great America Parkway                     |
| P. O. Box 58185                                |
| Santa Clara, CA 95052-8185  USA                |
| Phone: +1 408 495 1339                         |
| Fax:   +1 408 495 5615                         |
| E-Mail: thompson@xxxxxxxx                      |
| Please see the IEEE 802.3 web page at          |
| http://www.ieee802.org/3/index.html
| To download your FREE copy of Std. IEEE 802.3  |
| http://standards.ieee.org/getieee802/802.3.html