Re: Last Call: <draft-ietf-6lo-deadline-time-03.txt> (Packet Delivery Deadline time in 6LoWPAN Routing Header) to Proposed Standard

[Suresh Krishnan <Suresh@xxxxxxxxxx>]

Hi Tal,

On Dec 23, 2018, at 3:49 AM, Tal Mizrahi <tal.mizrahi.phd@xxxxxxxxx> wrote:

Hi,

I am not a 6lo native, but I reviewed the draft specifically from a timestamp formatting perspective.

In the NTP working group we currently have a draft in WGLC that presents guidelines for defining timestamp formats.

https://tools.ietf.org/html/draft-ietf-ntp-packet-timestamps-05

I believe that the definitions of the timestamps (DT and OT) in draft-ietf-6lo-deadline-time should be more detailed. For example, aspects about the epoch and the potential effect of leap seconds are currently not described in the current draft. 

Good point. Authors, can you add some further descriptive text around these fields.

I would suggest to follow the timestamp specification template of Section 3 in draft-ietf-ntp-packet-timestamps-05.

I think the semantics of the DT and OT fields are a bit different from the NTP packet timestamps and there are also resource constraints in the 6lo world that might make the 64 bit formats expensive. I will let the authors and the WG comment further on this.

Thanks

Suresh