Minutes for 0314: network media and PHY

Standard: IEEE Std 802.1Qcc-2018 Clause: various Draft with fix: Submitted: 2021-03-04
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Date Meeting Text Status
2021-05-07 4 May 2021 Interim It was recommended to reference a specific reference point within other standards (e.g. 802.3) for the point between the medium and the PHY. It was agreed that the use of PHY is problematic, but not clear solution was found just yet. The discussion was limited due to time constraints. Technical experts review
2021-06-22 22 Jun 2021 Concall Lots of discussion on the topic. It was agreed that the best solution would involve defining a reference point in 802.1AC and have each MAC then specify how to identify it. Then 802.1Q would use the 802.1AC reference point where appropriate. It was agreed to begin the next step by informally discussing with 802.3 and 802.11 how to identify such a reference point. Technical experts review
2021-07-29 29 Jul 2021 Concall A current project within 802.3 (P802.3cx) is defining a reference point at the MII that could be used as a good example for this purpose. It is recommended to review this draft to see if it is appropriate before committing to making changes to 802.1AC. Depending upon 802.3cx timing of the project completion and appropriateness of the solution we could consider updating Q in a future amendment or SA ballot for the revision to address this for 802.3. A quick search on P802.3cx timing is that it is headed for WG ballot in November, SA ballot in Jan 2022 and Revcom in June 2022 (this is a tentative schedule - see: https://www.ieee802.org/3/cx/P802d3cx_timeline_updated_7-2021.pdf) Technical experts review
2022-01-04 17 Jan 2022 Interim A refined set of next steps was discussed. The proposal is to bring further awareness of the issue to 802.3 by adding this to a Technical Plenary agenda and drafting text for an SA ballot comment on 802.3cx at a future maintenance meeting. Then draft potential text for 802.1AC or whichever standard makes most sense that defines the reference point in a non-MAC dependent way. Use this reference point in 802.1Q where appropriate. Further review of 802.3cx schedule indicated that they just finished the initial WG recirc, so the ballot pool for SA balloting has not yet been formed. The next meeting of 802.3 where 802.3cx is scheduled to be discussed in Jan 12, 2022 at 10AM. Technical experts review
2022-03-11 8 Mar 2022 Plenary The same set of next steps are still preferred, however, the order of them is important. The next step is to review the 802.3cx document that was provided by 802.3 and determine if this is a good example for a reference point and any proposed text changes to AC. This will be added to the agenda of the next maintenance call Technical experts review
2022-03-29 29 Mar 2022 Concall In reviewing 802.3cx, it was agreed that the bottom dashed line of Figure 90-5 (below the MDI) is the desired reference point to describe in 802.1Q when discussing a reference point for timing. See slide 5 of https://www.ieee802.org/1/files/public/docs2022/maint-congdon-em-0322-3-v01.pdf. This reference point, is not likely an observable reference point for the purposes of timing within 802.1Q and thus adjustments/estimations must be made from an actual measurement point. This is dependent upon the PHY in use and other factors, well described in 802.3cx. The 802.3cx standard describes the parameters and APIs available to make these adjustments. In 802.1AS and IEEE1588, the term "reference plane" is used to describe basically the same point, but for the purposes of the PTP protocol. We could use the same term, but we would need to make sure the definition is the same in 802.1Q to avoid confusion. It was agreed that defining such a reference point in 802.1AC is still the appropriate course of action, and this would need to be done before 802.1Q could make any changes to use the reference point. We have a number of proposed changes to 802.1AC that need to precede changes in 802.1Q, so we are needing to make sure these are in scope of any new project of 802.1AC. It was agreed to review 802.11 timing reference points to see if these could be used in a common description of an 802.1 reference point. Technical experts review
2022-05-13 10 May 2022 Interim No change. The current proposed action plan appears appropriate. Technical experts review