Hi Rory, Thanks for the detailed response.
A few follow-up questions/comments: >1. The draft currently does not clarify the use case. While the draft >describes how the timestamp is inserted into the NSH, I could not find a >description of how the timestamp is *used*, and what is the expected >accuracy. It is hard to assess whether the solution is adequate without >understanding the requirement. > >RB: We want to be able to tell if a VNF or and underlay segment is >misbehaving on subscriber traffic. Expected accuracy in the low 10s of >microseconds. 10s of microsecond: do you see this as a requirement, or is it a best practice based on what common IEEE 1588 equipment can provide? Can you please give a short example that explains why 10s of microseconds is necessary? I would strongly recommend to add a section in the draft (preferably at the beginning) that would describe these use cases and accuracy requirements in detail. >. Could you explain why you require very accurate frequency >synchronization, but inaccurate time synchonization (section 3.1)? > >RB: The time of day used at the start of the header does not have to be very >accurate (Can be 10's of ms out for example) the PTP needs to me more >accurate (in 10s of microsecond range) - Can you please clarify this point: what is the difference between how the timestamp-at-the-start-of-the-header is used and how the other timestamps are used? - PTP provides the time-of-day with a microsecond accuracy, so why would we need an additional less accurate time reference? > >. The format of the fields "UTC Reference", "Ingress Timestamp", and >"Egress Timestamp" is not clear. >RB: Can you explain > Based on your response, I understand that <UTC Reference> uses the NTP 64-bit timestamp format. Is the same format used also for <Ingress Timestamp> and <Egress Timestamp>? This should be defined explicitly in the draft. Cheers, Tal. _______________________________________________ TICTOC mailing list [email protected] https://www.ietf.org/mailman/listinfo/tictoc
