NTP

Summary

The NTP Working Group held an interim meeting to discuss the status of active drafts, address outstanding GitHub issues for NTPv5, and plan for the upcoming IETF meeting in Vienna. Two documents (NTP over PTP and Roughtime) have moved to the RFC Editor. The primary focus of the discussion was resolving four specific technical issues in draft-ietf-ntp-ntpv5 and progressing the early IANA allocation for the NTS pool extension.

Key Discussion Points

Working Group Status and RFC Editor Queue

Karen O’Donoghue provided an update on documents currently with the RFC Editor:

The NTP over PTP document has been in the queue for over 150 days.
The Roughtime document passed IESG review following substantive updates by the authors and is now with the RFC Editor.

NTP WG Chair Slides

Karen O’Donoghue presented the status of the current working group drafts.

draft-ietf-ntp-ntpv5: Network Time Protocol Version 5

Miroslav Lichvar and Tal Mizrahi discussed the status of the document. Four issues remain outstanding on GitHub:

Handling of flags in the header.
Greasing of extension fields.
Separating mandatory and optional parts.
Replacing the Bloom filter with a list of reference IDs.

Miroslav Lichvar noted that recent feedback has focused on text clarity rather than technical hurdles, but specifically requested broader community input on the Bloom filter vs. reference ID list issue.

Tal Mizrahi suggested that formal consensus calls would help move the document toward maturity. He identified the "Grease" suggestion and the "Bloom filter vs. reference ID list" as the two major items requiring consensus.

Karen O’Donoghue agreed to initiate separate email threads on the mailing list for these issues to solicit specific feedback. Regarding the separation of mandatory and optional parts, Tal Mizrahi will proceed with the implementation. Miroslav Lichvar and Tal Mizrahi will also work to finalize responses to Ulrich’s editorial review.

draft-ietf-ntp-nts-for-ptp: NTS4PTP - Network Time Security for the Precision Time Protocol

Karen O’Donoghue reported that progress continues in coordination with the IEEE 1588 (PTP) working group. An IANA-related question from Reiner is currently being addressed by the chairs. The document defines the additions to NTS required to support PTP.

draft-ietf-ntp-nts-keyexchange-pool: NTS extensions for enabling pools

Karen O’Donoghue noted that an early IANA allocation request was posted to the mailing list by David (not present). No objections have been raised so far. Ruben Nijveld concurred with the plan to progress the request. The chairs will issue a formal call for objections on the list before proceeding with IANA. Further reviews of this document are requested from the working group.

Decisions and Action Items

Decision: Tal Mizrahi will implement the separation of mandatory and optional parts in draft-ietf-ntp-ntpv5.
Action Item: Karen O’Donoghue to send specific consensus call emails to the mailing list regarding the Bloom filter replacement and greasing of extension fields in draft-ietf-ntp-ntpv5.
Action Item: Miroslav Lichvar or Tal Mizrahi to reply to the mailing list confirming which points from Ulrich’s review have been addressed.
Action Item: Chairs to formally query the mailing list regarding any objections to the early IANA allocation for draft-ietf-ntp-nts-keyexchange-pool.

Next Steps

IETF Vienna (July 2026): The WG plans to hold a hackathon project for NTPv5 on July 18–19. Authors aim to have a major update to draft-ietf-ntp-ntpv5 published before the meeting.
Interim Meeting: A short virtual interim is planned for late May or early June to track progress on the three active drafts.

Automatic IETF Minutes

NTP