NTP Working Group @ IETF 124
Tuesday, 4 November 2025
9:30 - 11:00 am EST (UTC -5)
Notre Dame
Notes: https://notes.ietf.org/notes-ietf-124-ntp
Please check https://datatracker.ietf.org/meeting/124/agenda for an
updated link to the meetecho session.
Draft Agenda
1. Administrative and Agenda Bashing (Chairs, 2 min)
- Note well
- Minutes: DS
- Agenda: No bashing
2. NTP WG Document Status Review/Update (Chairs, 5 min)
Roughtime
https://datatracker.ietf.org/doc/draft-ietf-ntp-roughtime/
Submitted to IESG
NTP over PTP
https://datatracker.ietf.org/doc/draft-ietf-ntp-over-ptp/
- The document has gone through IETF last call and IESG tele chat
- There is still one discuss on it which requires same text for
registry expert guidelines
NTS for PTP
https://datatracker.ietf.org/doc/draft-langer-ntp-nts-for-ptp/
Before proceeding with this document, the IEEE 1588 security
subcommittee has to resolve same basic open issues. To this end, a
face-to-face meeting is scheduled for December.
3. NTPv5 (Tal Mizrahi, 10 min)
https://datatracker.ietf.org/doc/draft-ietf-ntp-ntpv5/
Presentation:
https://datatracker.ietf.org/meeting/124/materials/slides-124-ntp-ntpv5-update-01
Discussion
- David: Open work regarding greasing of extension fields before WGLC.
- Karen: Please review the document. There is also a Github repro
where you can send pull requests to.
4. NTS for NTP pools (David Venhoek (remote), 10 min)
https://datatracker.ietf.org/doc/draft-venhoek-nts-pool/
- We have a fully functional experimental pool running.
- The address:
experimental.ntspooltest.org
- The draft is updated to match with that implementation
- On major change. Moved away from using TLS certificates for
authentication in favor for pre-shared tokens due to simpler setup
and deployment.
- Interested people may add servers to the pool.
- The working group should consider to adopt the document for early
allocation of extension field types.
Discussion
- David: The working group should consider to adopt the document for
early allocation of extension field types.
- Karen: Still interested in publishing as experimental?
- David: Yes
- Karen: We will do a call for adoption f on the mailing list.
5. Time Synchronization over QUIC (Garrett McCollum (remote), 10 min)
https://datatracker.ietf.org/doc/draft-mccollum-ntp-tsq/
Presentation:
https://datatracker.ietf.org/meeting/124/materials/slides-124-ntp-time-synchronization-over-quic-tsq-00
Discussion
- Tal: He ask if the resources required for this approach compared of
using NTP and NTS as been investigated? How does this impact
scalability and accuracy of clients and servers?
- Garrett: This question has not yet been examined in detail.
- Tal: Port 443. Is your intend to run time sync over port number 443?
- Garrett: Yes. No inference with https thanks to ALPN.
- David: is skeptical about the working group pursuing the project due
to limited capacity and the time-consuming nature of NTPV5. He
suggests prioritizing prototype testing to evaluate the feasibility
and scalability of the project before making a significant time
investment. He expresses concerns about the scalability of the
project, particularly in handling a large number of time requests
per second.
- Miroslav: He ask if it was considered simply to use NTP over QUIC.
- Mark Blanchet: He questioned the premise of "UDP is a problem" as
QUIC itself uses UDP. The draft should clarify that port 443 is
generally less filtered than port 123.
- Jeff Houston: He raised concerns about potential added
latency/jitter from QUIC's user-space processing compared to
kernel-level NTP.
- Karen: encourage the working group to follow the progress of
prototype implementation and testing. The working group may decide
later to specify an experimental RFC.
6. NTPv5 Algorithms (Sarah Grant (remote), 10 min)
https://datatracker.ietf.org/doc/draft-grant-ntp-ntpv5-algorithms/
Presentation:
https://datatracker.ietf.org/meeting/124/materials/slides-124-ntp-ntpv5-algorithms-00
Question for the WG
- Q1. Do algorithms need to be specified, or is referring to RFC 5905
enough?
- Q2. Is normative text required at all? Is an informative document
suļ¬cient?
- Q3. Are there any topics not yet included which are needed for
adoption?
#####Discussion
- David: Regarding Q2: We should be carefull with normative text of
algorithms.
- David: Regarding Q1. Specify behaviour only.
- Karen makes clear that we agreed to separate alg from the spec not
doing no algo
- Sarah: Current NTPv5 drafts points to RFC 5905.
- David: ... 1588 do not discuss algo and are doing well. References
may be enough
- Karen: But 1588 have algo in profiles. Next steps. Take this
questions to the mailing list.
7. Timestamp extension field (Dr. Ir. Siyu Tang (remote), 10 min)
https://datatracker.ietf.org/doc/draft-tang-ntp-ntpv5-extension-field/
Presentation:
https://datatracker.ietf.org/meeting/124/materials/slides-124-ntp-ntpv5-timestamp-extension-fields-01
#####Discussion
- Karen: The draft is already online
- David:
- Siyu: The M Raw clock is frequency stable. The draft encurge to use
m raw clock if available.
- David: My experience is that m raw clock is not a stable source of
frequency.
- Miroslav: Linux m clock is impacted by phase correction. It's
therefore not a good clock for frequency transport. The NTPv5 draft
requires the m clock to be stable and not impacted externally.
- Karen: We move this discussion to the mailing list. @All: please
provide comments.
8. Are NTP Clients Always Right? (Shreyas Konjerla (remote), 20 min)
Invited presentation from RIPE 91.
Presentation:
https://datatracker.ietf.org/meeting/124/materials/slides-124-ntp-understand-ntp-clients-shreyas-konjerla-00
#####Discussion
- Miroslav: Test of how much traffic the client generates. Was that
over the LAN or Internet.
- Shreyas: LAN
- Miroslav: This will influence the results
- Shreyas: LAN was considered as the best case.
- Miroslav: ...
- Karen: Further question please to Shreyas.
9. IEEE 1588 Update (Karen O'Donoghue, 10 min)
Presentation:
https://datatracker.ietf.org/meeting/124/materials/slides-124-ntp-ieee-1588-update-00
10. AOB (5 min)