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Re: [802.3af] Clocking over Ethernet


And as from an attending person not so titled as Geoff (802.3 Chair) and Steve (802.3af Chair), and one who attended the meeting in which the PAR was determined in York in 1999, and many other 'objective' determining meetings since, I also believe the time is past for this new wave (pun intended) of discussion on this very new idea. This discussion borders on a philosophical change in the Asynchronous nature of 802.3 itself by possibly providing an as needed synchronization mechanism... that either should have been mentioned a long time ago in AF (or even prior to that), or should be taken to a future effort.

But that's just my opinion.....

At 03:44 PM 8/1/2001 -0700, Geoff Thompson wrote:
>Steve Carlson is off the net and away from home for the day so I will take
>the liberty of providing a reply to your question.
>>Therefore, I ask whether discussions limited to the topic of how existing
>>802.3af proposals might support and/or preclude hypothetical future,
>>backward compatible, enhancements to provide synchronization support are
>>within scope,
>>or are they off topic for the reflector as well?
>They are off topic.
>1) I see no particular reason to think that DC power and time
>synchronization have any special relationship with each other.
>2) There was no mention whatsoever of the need for time sync during the
>period that this project was generating its PAR or formulating its
>objectives. The group has a set of formally agreed upon objectives that
>were voted on, approved, and forwarded to 802.3 for adoption as the part of
>the formal charter for the group.
>3) The Task Force is well beyond the conceptual design stage and is working
>very hard to refine the detailed specifications in support of their
>conceptual decisions.
>4) The group is behind schedule in terms of the goals that they set up for
>themselves. The goal of those who are actual members of the standards
>formulating group now is to get their draft through the refinement and
>approval process and finish the project.
>5) 802.3 has a process for determining interest in new topics of proposed
>additions to the 802.3 Standard. It does not involve going off-topic on the
>reflectors for existing projects. If you wish to try to generate a new
>project within 802.3 then you should (a) read the process at:
>and (b) get in touch with me directly.
>If you wish to pursue this further then you need to plan to attend meetings
>and become a voting member of 802.3.
>We would be delighted to have you join us.
>Future meeting information can be found at:
>Geoff Thompson, Chair, 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  |
>At 12:57 PM 8/1/01 -0700, Scott Carter wrote:
>>Steve and Colleagues -
>>Indeed there seems to be a danger of scope drift, which must be
>>fought.  On the
>>other hand, there appears to be perceived value in a mechanism which
>>power delivery with fine time synchronization support to the DTE(trying to
>>phrase that latter concept generically).  For the record, I agree with that
>>perceived value.  My company's adoption of 802.3af versus staying with our
>>existing homegrown combo power/sync over unused pairs, or preferrably some
>>other future standard that provides both, will be strongly affected by how
>>802.3af addresses the issue.  Others may be in the same boat, i.e. this
>>discussion is therefore relevant to the topic of the breadth of utility of
>>802.3af, and hence is within the PAR.
>>Therefore, I ask whether discussions limited to the topic of how existing
>>802.3af proposals might support and/or preclude hypothetical future, backward
>>compatible, enhancements to provide synchronization support are within scope,
>>or are they off topic for the reflector as well?
>>--- Steve Carlson <scarlson@xxxxxxxxxxxxx> wrote:
>> >
>> > Colleagues:
>> >
>> > The 802.3af Reflector is to be used only to support the work of the Task
>> > Force. As Geoff Thompson has stated, the "clocking over Ethernet" thread is
>> > not appropriate use of this reflector.
>> >
>> > The official policy on the use of this reflector is as follows:
>> >
>> > "The reflector can be used for announcements, comments, discussions, or
>> > dissemination of information related to the work of this study group."
>> >
>> > This topic is not part of the PAR or Objectives of 802.3af.
>> >
>> > Please move this discussion to another venue.
>> >
>> > Thank you.
>> >
>> > Regards,
>> >
>> > Steven B. Carlson
>> > President
>> > Co-Chair, ESTA Control Protocols Working Group
>> > Chair, ESTA ACN Task Group
>> >
>> > Chair, IEEE 802.3af DTE Power via MDI Task Force
>> >
>> > High Speed Design, Inc.
>> > 11929 NW Old Quarry Road
>> > Portland, OR 97229
>> > 503.626.4206
>> > FAX 503.626.4206
>> > scarlson@xxxxxxxxxxxxx

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