[core] Observe Cancellation: The outcome

Carsten Bormann <cabo@tzi.org> Fri, 07 March 2014 17:08 UTC

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From: Carsten Bormann <cabo@tzi.org>
Date: Fri, 07 Mar 2014 17:08:30 +0000
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To: "core@ietf.org WG" <core@ietf.org>
Archived-At: http://mailarchive.ietf.org/arch/msg/core/IYAmAN7_Gd_McK5Ie8NP8BB4XeY
Subject: [core] Observe Cancellation: The outcome
Precedence: list

After extensive discussion both in person at IETF89 and on the mailing list the CoRE WG today met to close the issue.
Two solutions emerged as the winners in their respective class:
1) a GET that looks like an Observation renewal (i.e., carries the options and the token of the ongoing request), but has a (TBD) value of the Observe option ≠ 0, cancels the Observation relationship instead.
2) a new code (0.31 possibly was the most favored one) indicates a cancel message; the ongoing request identified by the token in the cancel message is canceled.

After some more discussion, we first checked whether there was anyone that couldn’t live with one of the solutions.
Nobody showed their hands for either solution.
(Thomas indicated that he was unhappy with both, but that wouldn’t have helped with deciding.)

So we went to a hum. There was a strong, but not unanimous consensus for solution 1.

With respect to the value of TBD, the most basic value that is different from 0 (the vale of an empty Observe option, which we use for setting up and renewing Observation relationships) is 1.
Actually, any bits beyond the low order bit of the uint in the option should be ignored just in case we want to extend the (elective) request option later.

The successful cancellation is indicated by a GET response without an Observe option.
Any need to suppress the normal response of the GET will need to be handled by additional mechanisms such as the No-response Option.

As usual, we have to validate this result on the mailing list. Please indicate on the mailing list any serious problems you see with this result until

2014-03-14, 24:00 UTC

We will ship -observe-13 to the IESG on that date unless there is a major issue; that will be submitted in the next couple of days.

Grüße, Carsten

Re: [core] Observe Cancellation: The outcome Olaf Bergmann
[core] Observe Cancellation: The outcome Carsten Bormann
Re: [core] Observe Cancellation: The outcome Carsten Bormann
Re: [core] Observe Cancellation: The outcome Carsten Bormann
Re: [core] Observe Cancellation: The outcome FOSSATI, Thomas (Thomas)
Re: [core] Observe Cancellation: The outcome Carsten Bormann
Re: [core] Observe Cancellation: The outcome Peter A. Bigot
Re: [core] Observe Cancellation: The outcome Victor Blake
Re: [core] Observe Cancellation: The outcome FOSSATI, Thomas (Thomas)
Re: [core] Observe Cancellation: The outcome Zach Shelby
Re: [core] Observe Cancellation: The outcome Klaus Hartke
Re: [core] Observe Cancellation: The outcome Zach Shelby
Re: [core] Observe Cancellation: The outcome Klaus Hartke
Re: [core] Observe Cancellation: The outcome weigengyu
Re: [core] Observe Cancellation: The outcome Likepeng
Re: [core] Observe Cancellation: The outcome Robert Cragie