Re: [rtcweb] DTMF resolution proposal

["Asveren, Tolga" <[e-mail]>]

“WebRTC endpoints, such as browsers, will not do anything with RFC 4733 tones sent from the gateway, except gracefully drop them. There is currently no API to inform JavaScript about the received DTMF or other RFC 4733 tones.

Do you want the language added to the specification that WebRTC endpoint should be able to receive any RFC 4733 tones and process them in a graceful manner?”

This sounds strange to me (using digits unidirectionally) but I would think that browser vendors should weigh in on this one. For me, the practically important point is that gateway can send RFC4733 digits toward the browser/native WebRTC app without being restricted by the defined range. There wouldn’t be any issue from my perspective if browsers are anyhow going to drop the digits (I assume this would be the same for native WebRTC application) but *if* things change so that they may process them, then I would prefer the text to be clear that the range restriction does not apply for digits from a gateway toward the browser/native app.

Thanks,
Tolga


From: Roman Shpount [mailto:[e-mail]]
Sent: Wednesday, March 09, 2016 11:21 AM
To: Asveren, Tolga <[e-mail]>
Cc: Ted Hardie <[e-mail]>; Jean-Marc Valin <[e-mail]>; Cullen Jennings <[e-mail]>; [e-mail]
Subject: Re: [rtcweb] DTMF resolution proposal

On Wed, Mar 9, 2016 at 11:09 AM, Asveren, Tolga <[e-mail]<mailto:[e-mail]>> wrote:
 “WebRTC endpoint is specifically different from WebRTC-compatible endpoint. WebRTC-compatible endpoints do not have to implement OPUS or CN. They just need to interop with full WebRTC endpoints.”
As the bottom line, would a gateway need to comply with the range restrictions for the RFC4733 it is sending toward the WebRTC leg or not? I *think* what you say is that it does not. I strongly would prefer that the text is clear on this issue.


WebRTC endpoints, such as browsers, will not do anything with RFC 4733 tones sent from the gateway, except gracefully drop them. There is currently no API to inform JavaScript about the received DTMF or other RFC 4733 tones.

Do you want the language added to the specification that WebRTC endpoint should be able to receive any RFC 4733 tones and process them in a graceful manner?

I think I have previously proposed the following:

Receivers MUST be able to consume any audio/telephone-event events
in such a way that it will not generate audio artifacts, jitter buffer
adjustments, payload mismatches, or invalid RTCP statistics calculation.
Receivers MAY generate audio corresponding to the received events
but are also allowed to discard them in a manner that does not affect
regular audio processing.

This language was dropped as obvious, but can be included if you think is necessary and no one objects.

Regards,
_____________
Roman Shpount