[802.3af] Fwd: Additional Comment for SC25/WG3
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
1) My lack
of attendance since I wasn't contacted for Call-in bridge number
2) Lack of
attendance of others who may have wished to attend but didn't have the
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
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
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.
Date: Wed, 16 Jan 2002 17:43:45 -0800
To: "ISO - JTC1/SC25/WG3 Premises Cabling"
From: "Thompson, Geoff
Subject: Additional Comment for SC25/WG3
Cc: 380@xxxxxxxxxxxxxxxx, <stds-802-3-pwrviamdi@xxxxxxxx>,
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
(I think) or
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".
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
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.
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
2) The mid-span box has to be considered in one of 3 ways:
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).
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.
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.
| Chair IEEE
| Nortel Networks, Inc. M/S
| 4401 Great America
| P. O. Box
| Santa Clara, CA 95052-8185
| Phone: +1 408 495
| Fax: +1 408 495
| Please see the IEEE 802.3 web page
| To download your FREE copy of Std. IEEE 802.3 |
| 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 |
| To download your FREE copy of Std. IEEE 802.3 |