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Re: [Ntp] The bump, or why NTP v5 must specify impulse response

Kurt Roeckx <kurt@roeckx.be> Fri, 17 April 2020 14:41 UTC

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Date: Fri, 17 Apr 2020 16:41:39 +0200
From: Kurt Roeckx <kurt@roeckx.be>
To: Harlan Stenn <stenn@nwtime.org>
Cc: ntp@ietf.org
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References: <F7E5836A-4C7A-4A1A-B769-65EADE2C8F5C@gmail.com> <7d909ae3-a830-1270-6920-fa088a56525e@nwtime.org> <6C9832A9-E18B-4DE2-934F-9E471FC22F7B@akamai.com> <bc7920e2-dc81-ba7f-ec24-7926cda8589d@nwtime.org> <alpine.DEB.2.20.2004161430210.5561@grey.csi.cam.ac.uk> <93795d4a-25e7-c918-47d4-44aa6d92ee5e@nwtime.org> <20200416135547.GF412294@roeckx.be> <2d483354-a707-fbca-e914-cbe1479a4c25@nwtime.org> <CAJm83bAMxGrx_PSPQUjERzT2TT_0Tiutx=R0LRF2m9bY4QTj4w@mail.gmail.com> <39a14fe5-845d-aa3a-f236-5e767b6cce95@nwtime.org>
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Subject: Re: [Ntp] The bump, or why NTP v5 must specify impulse response
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On Fri, Apr 17, 2020 at 03:48:56AM -0700, Harlan Stenn wrote:
> More to the point, NTPv4 and all of its predecessors specified:
> 
> - the packet format
> - the algorithms
> - a set of behavioral limits and specifications
> 
> This means others were allowed to write specifications (regulations)
> assuming and/or relying on "NTP" - the packet format, algorithms, and
> behavior.
> 
> Removing or separating the algorithmic and behavioral specifications
> from the NTP specification at best cost-shifts that discussion
> elsewhere, and I submit it does this to groups that are likely
> completely unaware that they can no longer rely on behavior that they
> had no idea they previously relied on.

Maybe it's useful to have performance guarantees specified, but
leave the algorithm how to get there either to the
implementations, or in a separate document.


Kurt

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