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

Tony Finch <dot@dotat.at> Tue, 19 October 2021 15:07 UTC

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Date: Tue, 19 Oct 2021 16:06:52 +0100
From: Tony Finch <dot@dotat.at>
To: Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>
cc: james.ietf@gmail.com, mlichvar@redhat.com, "ntp@ietf.org" <ntp@ietf.org>, doug.arnold@meinberg-usa.com
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Subject: Re: [Ntp] Antw: [EXT] Re: New Version Notification for draft-gruessing-ntp-ntpv5-requirements-03.txt
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Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de> wrote:
>
> 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. Maybe NTPv6 will demand that TAI should be the new time base. Still
> we would need the offset to provide UTC and similar.

The packet will also need some kind of leap indicator, because if a client
only has the current timestamp and offset, and is not aware it is in the
middle of a positive leap second, the client cannot know whether it is
2016-12-31 23:59:60 or 2017-01-01 00:00:00. (This is true whether the
timestamp is trad NTP or counts TAI seconds.)

Tony.
-- 
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