Re: [Roll] call for consensus for the RPL RPI / RH3 compression

"Adrian Farrel" <> Sun, 04 January 2015 11:59 UTC

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From: Adrian Farrel <>
To: 'Routing Over Low power and Lossy networks' <>
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Date: Sun, 04 Jan 2015 11:59:52 -0000
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Subject: Re: [Roll] call for consensus for the RPL RPI / RH3 compression
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Thanks for continuing to try to wrangle this situation.

> someone wrote;
>     >> So, it seems prudent (to me) to look at each of the alternatives and
>     >> determine which warts everyone concerned is willing to live with.
>     >> Running code is a good way to do that.
> Carsten Bormann <> wrote:
>     > I agree with Xavi here: This is a good way to gather data for
>     > implementation issues (such as the implementation complexity of the
>     > “efficient” variant of the NHC approach).  It is not so good
> so, I think that we have consensus that this can not be left to the plugfest.

I understand that the plugfest has to have a baseline: you can't arrive at the plugfest with lots of implementations of different things!

On the other hand, I don't think that the WG has to agree what the plugfest will do. I think it is fine for some group of people to make that agreement (by all means point at existing I-Ds or even write a brief I-D or wiki page saying "this is what we will test").

If everyone has energy, the plugfest could even test more than one approach.

> A number of people have not replied; some ADs and some WG chairs.
> (I realize that Gabriel Montenegro is new in this position; maybe he can
> bring a fresh viewpoint?)

Is there a specific question you'd like this AD to answer?

> I am going to put up a doodle poll for the week of Jan. 12.
> My goal is not to need it, that we will have a plan for the Jan 9, 6tisch
> call.

I didn't see anything further on this.

> Please: how do we proceed?

Consensus can sometimes be hard-won and slow. It is one of the things that makes people claim the IETF is slow. On the other hand, the alternative to consensus is, erm, no consensus.

In agreeing consensus, however, we may need to declare minority opinions "in the rough" [RFC7282] if there is a body of opinion that one way of doing things is preferred and if the drawbacks of that approach are clearly recognised and accepted.

I see the plugfest as an important way of reaching consensus on this issue. That is, if the plugfest shows that a particular approach is functional and not harmful it provides a strong case for documenting and standardising the mechanism.

Beyond that it may be most helpful to note the objections to the "preferred" approach and to write text that explains the concerns and how they are mitigated (for example, not sending traffic out of admin domains without applying some magic policy).