Session Date/Time: 26 Feb 2026 15:00

NTP

Summary

The NTP working group held an interim meeting to discuss the status of existing documents, particularly NTPv5 and NTS for NTP Pools. Key points of discussion included outstanding pull requests for NTPv5, updates on NTS for PTP and CSPTP, and a call for adoption for the NTS for NTP Pools draft. The group also briefly touched upon new individual submissions, including a DNS resource record for NTP and the NTPv5 algorithms draft. The upcoming IETF 125 (Shenzhen) meeting was announced, with a focus on Asian region contributors, and plans for a hackathon at the IETF Vienna meeting were outlined.

Key Discussion Points

Meeting Logistics & Housekeeping:
- Initial audio difficulties resolved.
- The IETF Note Well was invoked.
- Acknowledgements for outgoing Area Director Eric Klein and welcome for incoming AD Tommy Jensen.
- Meeting notes page and agenda link shared in chat.
Document Status Updates:
- NTP over PTP: Still with the RFC Editor.
- Rough Time: Scheduled for IESG telechat next week.
NTPv5 (draft-ietf-ntp-ntpv5):
- Miroslav noted several small clarifications in the Git repository.
- Four outstanding pull requests were identified lacking consensus:
  - Greasing of extension fields (proposed by David). David suggested reiterating points on the mailing list; Tal agreed a consensus call could be helpful.
  - Change in the specification of flags (disagreement between Miroslav and David).
  - Separating optional from mandatory parts (proposed by David). Miroslav suggested moving authentication to optional parts.
  - Replacement of the Bloom filter with a weighted list. David expressed he needs more time for experiments and evaluation.
- The Chair suggested consensus calls to prompt more mailing list discussion and bring topics to closure.
- Miroslav was asked to submit a new draft version before the IETF 125 meeting, incorporating some changes.
Upcoming Meetings:
- An NTP WG meeting is scheduled for IETF 125 (Shenzhen, Tuesday at 13:00 Shenzhen time). The rationale is to accommodate contributors from the Asia region. Remote participation fee waivers are available.
- A hackathon focused on NTPv5 and NTS for PTP activities is planned for the IETF Vienna meeting.
NTS for PTP (draft-ietf-ntp-nts-for-ptp):
- Martin updated that a new draft was uploaded, including a ticket TLV for security association transport (an organizational TLV for PTP).
- A new record for the key exchange phase with the NTS key server was added to transmit the current time of the signal key establishment server for replay protection.
- The time format (TIA vs. UTC) for timestamps in the sequence number field is still being clarified with IEEE.
- Other changes were minor wording corrections.
NTS for CSPTP:
- David reported not much has changed recently. A draft dealing with CSPTP message authentication is under consideration within the IEEE 1588 group.
- NTS functionality would remain largely identical, with no changes needed from the IETF. The use of NTS would be specified by 1588.
- The main discussion in IEEE concerns one-step versus two-step timing on the transparent clock side and client/server support.
- Chair offered to share access to 1588 documents for review purposes to interested WG members.
NTS for NTP Pools (draft-ietf-ntp-nts-for-ntp-pools):
- Discussion around the Call for Adoption, with some comments on the mailing list about alternative approaches.
- The Chair emphasized that the draft is proposed as an Experimental RFC to gain operational experience. Adoption does not imply full agreement with every detail, but rather the importance of the work.
- David, Ruben, and others expressed support for adopting the draft to enable experimentation, given its current running implementations and the significant percentage of NTP traffic served by the NTP Pool.
Individual Submissions:
- DNS Resource Record for NTP (draft-goto-ntp-dns-resource-record):
  - Goto presented the draft, proposing a DNS record (inspired by HTTPS SVCB records) for servers to advertise NTP versions, extensions, and port information to clients in advance of connection.
  - David expressed skepticism about its practical utility, citing the complexity of implementing custom DNS record lookups in clients and existing negotiation mechanisms within NTPv5 and NTS.
  - The Chair indicated a follow-up call for comments would be issued to gather use cases from the mailing list.
- Time Extension Field (draft-ietf-ntp-extension-field-timestamp): No specific discussion.
- NTPv5 Algorithms (draft-ietf-ntp-ntpv5-algorithms):
  - David felt the draft was "very early" and questioned who would have the knowledge and inclination to advance it.
  - Miroslav reiterated that core protocol specifications shouldn't necessarily include clock steering and selection algorithms, though a separate document for certain algorithms (e.g., Bloom filter processing) might be needed.
IEEE 802.1 Update:
- Ira provided an update on IEEE 802.1 Secure Device Identity, which is being fast-tracked to add support for MLChem and MLDSA due to critical system requirements and regulations. Target publication is by September.

Decisions and Action Items

Decision: The sense of the room leans towards adopting the NTS for NTP Pools (draft-ietf-ntp-nts-for-ntp-pools) as an Experimental RFC. The Chair will summarize this on the mailing list and issue a formal call for opposition to adoption under this understanding.
Action Item: Miroslav and Tal to send a summary of the four outstanding NTPv5 issues (greasing, flags, optional parts, Bloom filter) to the mailing list for further discussion.
Action Item: Chair to solicit comments on use cases for the DNS Resource Record for NTP (draft-goto-ntp-dns-resource-record) via the mailing list.
Action Item: Chair to follow up with Sarah on the NTPv5 Algorithms (draft-ietf-ntp-ntpv5-algorithms) draft to determine next steps.
Decision: An NTP working group meeting will be held during IETF 125 in Shenzhen.

Next Steps

Miroslav is requested to submit an updated NTPv5 (draft-ietf-ntp-ntpv5) draft prior to the IETF 125 meeting.
The Chairs plan to schedule a virtual interim meeting sometime after IETF 125, leading up to the IETF Vienna meeting.
A goal is to be ready for a Working Group Last Call on the NTPv5 documents by the IETF Vienna timeframe.
Planning will begin for an NTPv5 and NTS for PTP hackathon at the IETF Vienna meeting.