Session Date/Time: 14 Dec 2023 16:00

NTP

Summary

The NTP Working Group met virtually to discuss the status of ongoing documents, primarily focusing on two Working Group Last Calls (WGLCs): "NTP over PTP" and "NTPv5 Requirements." Both WGLCs were extended until December 31st to allow for more reviews and address outstanding comments. Discussions also covered updates on "NTPv5 Protocol Specification," "Rough Time," and "NTS for PTP." An experimental prototype for NTS Pools was presented, garnering interest for an early draft.

Key Discussion Points

Administrative Notes:
- This was the first MeetEcho virtual meeting for the WG.
- Participants reminded of IETF Note Well, Code of Conduct.
- Online notes tool used for draft minutes, contributions encouraged.
- Blue sheets managed by MeetEcho sign-in. Q tool (hand raising) for comments.
- David asked to add NTS Pool discussion to the agenda, which was accepted and placed at the end.
Documents Beyond Working Group Last Call:
- NTP Registries Update: Rich's recent updates require AD approval.
- Enterprise Profile: Awaiting AD review and shepherd write-up to address Eric's comments.
- Kronos: Has passed ISG review and is now in the RFC Editor queue.
NTP over PTP Working Group Last Call Results:
- The WGLC received a limited number of responses, with no opposition, but only four explicit comments.
- Miroslav found the suggestions received so far to be good.
- A sense of those present indicated a desire for more reviews, particularly from the 1588 community.
- An open question regarding an organizational ID for IETF from Doug remains outstanding.
NTPv5 Requirements Working Group Last Call Results:
- This informational document received a fair amount of discussion on the mailing list.
- Two main sets of comments were discussed:
  - A "hard no" from Harlen, which the chairs and AD will address.
  - Editorial and tonal comments from Kristoff, with some questioning of past consensus points. Kristoff noted his suggestions aim for concrete, sentence-level clarifications.
- James raised concern about reopening discussions that had long since concluded, and the impact on progressing the NTPv5 protocol itself. He urged time-boxing changes.
- Kristoff specifically expressed strong doubt regarding the working group's consensus on leap smearing, fearing future complexity if support for it (even if deprecated) is mandated.
- David clarified that "supporting leap smearing" could be interpreted as the client's ability to identify it and choose how to handle it, rather than mandating server-side smearing, which seemed to ease Kristoff's concern.
- Ira expressed concern about the use of "MUST" and "REQUIRED" in an informational document, suggesting "SHOULD" would be more appropriate for recommendations.
- An email from Daniel, which was not sent to the mailing list, was mentioned; chairs will follow up with him.
- David offered to help summarize the various comments to lighten the load on the editor.
Updates on Ongoing Work Items:
- NTPv5 Protocol Specification: No new updates from Miroslav; reminder for more mailing list comments.
- Rough Time:
  - Watson reported fixes by Chris Pat to infelicities; new version to be submitted. Introductory sections have been revised.
  - David questioned the protocol's complexity, suggesting merging its cryptographic features into NTP as an extension rather than maintaining a separate time synchronization protocol, to avoid dual discussions on time scales and leap seconds.
  - Chris (Cloudflare) provided an implementer's perspective, highlighting current deployment and a desire for stabilization, not significant changes in direction.
  - James queried the status of the "Rough Time Ecosystem" draft, especially concerning observation of "malfeasance."
  - Watson confirmed the "Ecosystem" draft is abandoned, with relevant material folded into the main "Rough Time" draft. The focus is on the "boot-up on a system with no clock" problem, and sub-second precision has been removed.
  - David raised concerns about web PKI-like key rotation. Chris clarified the proposal is for key multiplexing (supporting two keys at once) rather than full PKI-style rotation/root store management, aiming to avoid operational security requirements akin to web PKI.
  - James emphasized the need for clearer guidance on temporal keys (Min_TE, Max_TE) to minimize mishandling.
  - Watson and Chris anticipate the next update in January, hoping it could be ready for WGLC.
- NTS for PTP: Martin, unavailable for the call, hopes to have a solid draft update by March.
Any Other Business: NTS Pool Work
- David reported on an experimental prototype for NTS pools, funded recently.
- The solution aims for a distributed trust model for NTS servers, where clients don't require changes (it looks like a standard NTS endpoint).
- It allows multiple backend servers from different operators, with a level of trust separation.
- The prototype works with their NTP software and provides reasonable results, requiring some extensions from individual servers.
- David sought interest from the working group in seeing an early draft of these extensions, rather than waiting for a fully running system.
- Watson expressed interest in reviewing the security aspects.
- A sense of those present indicated interest in receiving an early draft. David plans to publish something next week or early next year.

Decisions and Action Items

Decision: The Working Group Last Call for "NTP over PTP" is extended until December 31, 2023, to encourage more reviews, especially from the 1588 community.
Decision: The Working Group Last Call for "NTPv5 Requirements" is extended until December 31, 2023, to allow for addressing comments.
Action Item: Chairs (D) to follow up with Daniel regarding un-mailed comments on "NTPv5 Requirements" and request they be sent to the mailing list.
Action Item: AD (Eric) to assist chairs with responding to Harlen's opposition comments on "NTPv5 Requirements."
Action Item: David offered to summarize Kristoff's comments on "NTPv5 Requirements" to aid the editor.
Action Item: David to prepare and publish an early draft on NTS Pool work for working group review by next week or early next year.
Action Item: Watson and Christopher to provide the next published update for the "Rough Time" draft in January 2024.
Action Item: Chairs to plan the next virtual interim meeting for late January 2024, aiming for a slightly later time slot to accommodate global participation.

Next Steps

All working group members are encouraged to review and comment on the "NTP over PTP" and "NTPv5 Requirements" drafts before the extended WGLC deadline of December 31, 2023.
Look out for David's early draft on NTS Pool work.
Anticipate a new version of the "Rough Time" draft in January.
Details for the next virtual interim meeting (late January) will be announced.