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

["DRAGE, Keith (Keith)" <[e-mail]>]

I'm still confused.

Surely PCMU0 was recommended before this update and is recommended now.

DVI4 was recommended before this update and is now optional.

I guess the result of that is that I can be conformant but implement neither, although it will not be a terribly useful implementation.

Regards

Keith



> -----Original Message-----
> From: Colin Perkins [mailto:[e-mail]]
> Sent: 15 March 2013 18:00
> To: DRAGE, Keith (Keith)
> Cc: Magnus Westerlund; IETF AVTCore WG
> Subject: Re: [AVTCORE] WG last call on draft-ietf-avtcore-avp-codecs-01
> 
> 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/
> 
>