Re: [Roll] MOP 7

Michael Richardson <mcr+ietf@sandelman.ca> Wed, 20 November 2019 06:14 UTC

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From: Michael Richardson <mcr+ietf@sandelman.ca>
To: Routing Over Low power and Lossy networks <roll@ietf.org>
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Comments: In-reply-to Rahul Jadhav <rahul.ietf@gmail.com> message dated "Tue, 19 Nov 2019 17:06:22 +0800."
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Date: Wed, 20 Nov 2019 14:14:53 +0800
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Subject: Re: [Roll] MOP 7
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Rahul Jadhav <rahul.ietf@gmail.com> wrote:
    Pascal> Yesterday we said that if MOP is 7 then the MOPext is expected
    Pascal> else the packet is dropped. An alternate could be to say that if
    Pascal> MOP is 7 in the DIO and the MOPext is not present then the MOP is
    Pascal> non-storing, since this is the most widely used mode in constrained networks. 

    > [RJ] The advantage, I assume, is that not having MOPex will save bytes
    > in the DIO for the common case. This would result in three
    > representations for non-storing MOP:
    > a. base MOP = 1 ... RPLv1
    > b. base MOP = 7 ... without MOPex ... RPLv2
    > c. base MOP = 7 ... MOPex = 7 ... RPLv2
    > For the sake of simplicity, I would prefer to mandatorily use MOPex if
    > MOP=7. Simplicity I refer to is, Base MOP = 7 would mean, go check
    > MOPex value.

I agree.

    Pascal> We also said that a MOP of 7 means RPLv2, which packages new
    Pascal> support we are defining. Q is what’s mandatory and what’s
    Pascal> optional.

I think that we are working on MOPex because we are concerned about running
out, and we want to establish the rules for extending things early on.

But, I don't think that we need to rush to defining "RPLv2": which I think
would imply that CAP would provide the useful info.

-- 
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