Re: [rtcweb] Fwd: Last Call: <draft-ietf-rtcweb-audio-10.txt> (WebRTC Audio Codec and Processing Requirements) to Proposed Standard

[Roman Shpount <[e-mail]>]

Tolga,

In the proposed text I have copied the requirements from
https://www.w3.org/TR/webrtc/#rtcdtmfsender to make sure specifications are
consistent with each other. Here is the text present in WebRTC TR:

The duration parameter indicates the duration in ms to use for each
character passed in the tones parameters. The duration cannot be more than
6000 ms or less than 40 ms. The default duration is 100 ms for each tone.

The interToneGap parameter indicates the gap between tones. It must be at
least 30 ms. The default value is 70 ms.


I believe the limits in WebRTC TR are based on ITU-T Q.24, which are, in
turn, based on physical limitation imposed by transmitting DTMF tones using
8Khz audio. It is physically impossible to design an inband DTMF detector
which can detect DTMF digits of duration less then 40 ms with gaps less
then 30 ms and still be capable of handling talk off. This requirement is
the MUST level to provide minimal support necessary for PSTN interop.

Regards,
_____________
Roman Shpount

On Thu, Feb 25, 2016 at 2:44 PM, Asveren, Tolga <[e-mail]>
wrote:

> Roman,
>
>
> What is the rationale of having this "MUST" strength mandate?
>
>
> Thanks,
>
> Tolga
>
>
> ------------------------------
> *From:* rtcweb <[e-mail]> on behalf of Ted Hardie <
> [e-mail]>
> *Sent:* Thursday, February 25, 2016 1:07 PM
> *To:* [e-mail]
> *Subject:* [rtcweb] Fwd: Last Call: <draft-ietf-rtcweb-audio-10.txt>
> (WebRTC Audio Codec and Processing Requirements) to Proposed Standard
>
> Mailman claims this was auto-discarded and it doesn't show in the
> archives, so I'm forwarding.  I will separately check on why it got chucked.
>
> regards,
>
> Ted
> ---------- Forwarded message ----------
> From: Jean-Marc Valin <[e-mail]>
> Date: Wed, Feb 24, 2016 at 2:21 PM
> Subject: Re: [rtcweb] Last Call: <draft-ietf-rtcweb-audio-10.txt> (WebRTC
> Audio Codec and Processing Requirements) to Proposed Standard
> To: Roman Shpount <[e-mail]>, [e-mail],
> [e-mail], "[e-mail]" <[e-mail]>,
> [e-mail]
>
>
> On 02/24/2016 04:42 PM, Roman Shpount wrote:
> > Generated events MUST have duration of no more than 6000 ms and no
> > less than 40 ms with the recommended default duration of 100 ms for each
> > tone. The gap between events MUST be no less then 30 ms with the
> > recommended default duration of 70 ms.
>
> OK, I missed that part, but I'm fine with it. Unless anyone objects, I
> can add it to the draft.
>
>         Jean-Marc
>
>
> > Regards,
> > _____________
> > Roman Shpount
> >
> > On Wed, Feb 24, 2016 at 4:31 PM, The IESG <[e-mail]
> > <mailto:[e-mail]>> wrote:
> >
> >
> >     The IESG has received a request from the Real-Time Communication in
> >     WEB-browsers WG (rtcweb) to consider the following document:
> >     - 'WebRTC Audio Codec and Processing Requirements'
> >       <draft-ietf-rtcweb-audio-10.txt> as Proposed Standard
> >
> >     The IESG plans to make a decision in the next few weeks, and solicits
> >     final comments on this action. Please send substantive comments to
> the
> >     [e-mail] <mailto:[e-mail]> mailing lists by 2016-03-09.
> >     Exceptionally, comments may be
> >     sent to [e-mail] <mailto:[e-mail]> instead. In either
> >     case, please retain the
> >     beginning of the Subject line to allow automated sorting.
> >
> >     Abstract
> >
> >
> >        This document outlines the audio codec and processing requirements
> >        for WebRTC endpoints.
> >
> >
> >
> >
> >     The file can be obtained via
> >     https://datatracker.ietf.org/doc/draft-ietf-rtcweb-audio/
> >
> >     IESG discussion can be tracked via
> >     https://datatracker.ietf.org/doc/draft-ietf-rtcweb-audio/ballot/
> >
> >
> >     No IPR declarations have been submitted directly on this I-D.
> >
> >
> >     _______________________________________________
> >     rtcweb mailing list
> >     [e-mail] <mailto:[e-mail]>
> >     https://www.ietf.org/mailman/listinfo/rtcweb
> >
> >
>
>
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