Re: [AVTCORE] WG last call on draft-ietf-avtcore-avp-codecs-01

[Colin Perkins <[e-mail]>]

On 12 Mar 2013, at 16:40, DRAGE, Keith (Keith) wrote:
> I'm trying to parse the final sentence of the change made to RFC 3551.
> 
> Essentially this i-d modifies:
> 
> "   Audio applications operating under this profile SHOULD, at a minimum,
>   be able to send and/or receive payload types 0 (PCMU) and 5 (DVI4).
>   This allows interoperability without format negotiation and ensures
>   successful negotiation with a conference control protocol."
> 
> To become:
> 
> "   Audio applications operating under this profile SHOULD, at a minimum,
>   be able to send and/or receive payload type 0 (PCMU).
>   This allows interoperability without format negotiation and ensures
>   successful negotiation with a conference control protocol. Some
>   environments MAY make support for PCMU mandatory."
> 
> What the final sentence currently says is that some environments provide an option to make support for PCMU mandatory, which implies that other environments do not provide such an option. Neither of those make sense to me and there I believe that cannot be the meaning.
> 
> I suspect we are looking for sentence that looks more like "Some environments REQUIRE support for PCMU", but I am not sure if there is an "only" floating around in there somewhere.


I don't think the draft ought to say "only". This sentence looks to be addressing the RTCWeb use case, which makes PCMU mandatory to implement but also allows other codecs. 

To my reading, "Some environments MAY make support for PCMU mandatory" and "Some environments REQUIRE support for PCMU" are equivalent, but I have no objection to the change if you think it clearer.

-- 
Colin Perkins
http://csperkins.org/