Subject: Re: [Ntp] Antw: [EXT] Re: New Version Notification for draft-gruessing-ntp-ntpv5-requirements-03.txt

From: Danny Mayer <[email-masked]>
Date: Tue, 19 Oct 2021 11:22:12 -0400

On 10/19/21 4:17 AM, Miroslav Lichvar wrote:
> On Tue, Oct 19, 2021 at 10:01:45AM +0200, Ulrich Windl wrote:
>>>>> Miroslav Lichvar <[email-masked]> schrieb am 18.10.2021 um 16:33 in
>> Nachricht <YW2FvUiaHC/hbxkG@localhost>:
>>
>> ...
>>> Same for UTC vs TAI.
>> I thing the TAI offset (whole seconds) should be part of every NTPv5 timing packet. So we can keep the old timestamp format while providing TAI.
> That's the Timescale Offset field in my draft. If the selected
> timescale is UTC or TAI, it contains the TAI-UTC offset, or 0x8000 if
> unknown. The expectation is that client will request the timescale
> which it is using for timestamping of NTP packets.
It's better that the offset be zero rather than 0x800 to indicate that 
it doesn't know. That way there will be no mistake.
>> Maybe NTPv6 will demand that TAI should be the new time base. Still we would need the offset to provide UTC and similar.
> If all computer clocks were keeping time in TAI, or at least could
> convert all their timestamps to TAI, that would make sense. But I
> think it's more likely that UTC will stop leaping before TAI is
> adopted everywhere.
>
That would have been great more than 20 years ago, but whoever decided 
to do it this way had their own reasons, probably lost in the mists of 
time! :)

Danny