Re: [Ntp] Antw: Re: Antw: [EXT] Re: Robert Wilton's Discuss on draft‑ietf‑ntp‑interleaved‑modes‑05: (with DISCUSS and COMMENT)

Miroslav Lichvar <> Thu, 22 July 2021 10:37 UTC

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Date: Thu, 22 Jul 2021 12:37:42 +0200
From: Miroslav Lichvar <>
To: Ulrich Windl <>
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Subject: Re: [Ntp] =?utf-8?q?Antw=3A_Re=3A__Antw=3A_=5BEXT=5D_Re=3A_Robert_Wi?= =?utf-8?b?bHRvbidzIERpc2N1c3Mgb24gZHJhZnTigJFpZXRm4oCRbnRw4oCRaW50ZXJs?= =?utf-8?q?eaved=E2=80=91modes=E2=80=9105=3A__=28with_DISCUSS_and_COMMENT?= =?utf-8?q?=29?=
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On Thu, Jul 22, 2021 at 11:19:26AM +0200, Ulrich Windl wrote:
> >>> Miroslav Lichvar <> schrieb am 22.07.2021 um 10:51 in
> > My opinion still is that clients that set their origin timestamp to
> > anything else than zero or the transmit timestamp from the received
> > packet don't follow the NTP specification. It's not a subset of the
> > protocol.
> Your opinion is different from the RFC 5905:
> "Origin Timestamp (org): Time at the client when the request departed
> for the server, in NTP timestamp format." (page 23)

If you were implementing a client and read that description out of the
context, what exactly would you put in the field? The client's
transmit timestamp?

When you read the text that follows that description:

   Receive Timestamp (rec): Time at the server when the request arrived
   from the client, in NTP timestamp format.

   Transmit Timestamp (xmt): Time at the server when the response left
   for the client, in NTP timestamp format.

what would you put in the transmit timestamp field?

That is obviously a description from the server's point of view.

To see how the timestamps are set in the client request, you need to
look at the diagram in the "On wire protocol" section, or Figure 30 in
the "Poll Process Operations" section, which has " <-- p.xmt".

The document is quite confusing in some parts, but I don't see
anything that could lead you to set the origin timestamp in the
request to the server's receive timestamp (i.e. make a request in the
interleaved mode).

Miroslav Lichvar