Re: [MMUSIC] AD Evaluation of draft-ietf-mmusic-rfc4566bis-32

Colin Perkins <> Thu, 14 March 2019 15:02 UTC

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From: Colin Perkins <>
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Date: Thu, 14 Mar 2019 15:02:05 +0000
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Subject: Re: [MMUSIC] AD Evaluation of draft-ietf-mmusic-rfc4566bis-32
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> On 12 Mar 2019, at 15:41, Paul Kyzivat <> wrote:
> On 3/12/19 7:08 AM, Colin Perkins wrote:
>>>>>>> This is a normative requirement of RTP, however. If we want to avoid normative examples, which I’d agree makes sense, then this needs to be rewritten as just “An RTP-based system in recvonly mode SHOULD…”.
>>>>>> That is the way it was. The change from "SHOULD" to "should" was to make it non-normative.
>>>>>> Or were you requesting to remove “e.g."?
>>>>> Remove the “e.g.”, yes, but also change “should” back to “SHOULD”.
>>>> I thought the point was that the RTP specs are normative and this is only an example, and so shouldn't be normative.
>>> I do not have the text in front of me, but I agree that examples should not be stated normatively.
>> This is documenting a perhaps unexpected interaction between SDP and RTP. That is, when set to recvonly in SDP, an RTP endpoint SHOULD send RTCP. I do think that it’s important that we spell this out clearly here, with normative language.
> I'm neutral here whether its normative or not. If it is to be a normative SHOULD, can we please include some "unless" text indicating the conditions when it may be omitted? Better yet, turn it into an "if NOT x then MUST ..." form.

I don’t think I can summarise the rules around when RTCP is, or is not, to be sent as a simple condition. If more detail is needed, I suggest “An RTP-based system in recvonly mode SHOULD still send RTCP packets as described in [RFC3550] Section 6”.

Colin Perkins