[rtcweb] Support DTMF "codec" or expose DTMF in signaling? (Re: DTMF usecase before DTMF API)

[Harald Alvestrand <[e-mail]>]

On 11/18/2011 11:02 AM, Hadriel Kaplan wrote:
> On Nov 17, 2011, at 9:46 PM, Harald Alvestrand wrote:
>>>   AFAIK, DTMF is not directly going to useful in browser-browser scenario and it is possible to pass DTMF in the signaling layer for H.323, SIP in the standard manner.
>> What do you mean by "the standard manner"?
> H.323 and SIP both offer a signaling-plane means of indicating DTMF, other than RFC 2833/4733.  For H.323 it's H.245 User Input Indications (UII) messages.  For SIP it's officially KPML (RFC 4730), but in practice it's not popular.  Two vendors I know of support it, but it's a drop in the bucket compared to rfc2833 or SIP INFO.
OK, thanks.

So the discussion that is really part of the IETF's task here is to pick 
one (and preferably one) way that WebRTC applications are recommended to 
do DTMF.

If we accept draft-cbran's codec recommendation, it follows that an API 
must be standardized in the W3C, and discussion of the form of that API 
should go to the W3C list.

But I agree that the discussion on what the recommendation should be 
needs to happen here.

                      Harald