Re: [6lo] Genart last call review of draft-ietf-6lo-deadline-time-03

[Charlie Perkins <[e-mail]>]

Hello Dale,

I made some brief follow-up to your comments inline below.  I think we 
are in agreement about what needs to be done.

On 2/14/2019 6:37 PM, Dale R. Worley wrote:
> Charlie Perkins <[e-mail]> writes:
>> I'm not sure about this because even in 6TiSCH networks, one could
>> imagine using NTP-based time representations.  Besides that, we'd really
>> like to avoid restricting the use of the Deadline-6LoRHE to only 6TiSCH.
> I agree that one could imagine any number of schemes, and in the long
> run, broad use of Deadline-6LoRHE is desirable.  But that doesn't change
> the fact that while the draft purports to define the meaning of three
> values of the TU field, for two of those values, the draft doesn't
> specify what zero-point is being used for the time scale, and so
> implementations using those values cannot ensure interoperation.
>
> Now if what you really mean is "NTP time scale in microseconds" and "NTP
> time scale in seconds", those *are* definitions.  But that's not what the
> draft says.


We have revamped the way of representing the deadline time and optional 
origination time, and I think it will resolve your comments here.  In a 
nutshell, we are following the recommendations in 
draft-ietf-ntp-packet-timestamps.


> ...
>> We will rework the time representation and show a proposed new format
>> soon.  I agree that, if both values are present, one should be a delta
>> from the other.
> The way you write that suggests that either or both of the times can be
> present.  But the deadline time is not optional.  So if the origination
> time is present, both times are present.


Agreed, and the new revision will make this clear as well.

Regards,
Charlie P.