W3C home > Mailing lists > Public > public-webrtc@w3.org > January 2014

Re: Min DTMF Gap

From: Roman Shpount <roman@telurix.com>
Date: Thu, 16 Jan 2014 19:43:07 -0500
Message-ID: <CAD5OKxv4Fz7kG72euQt_S736Tkm-+P-33vT9TP0xfbTTemboZA@mail.gmail.com>
To: "Cullen Jennings (fluffy)" <fluffy@cisco.com>
Cc: "public-webrtc@w3.org" <public-webrtc@w3.org>
I was the person who asked for this change.

Based on http://www.itu.int/rec/T-REC-Q.24-198811-I/en Annex A, valid tone
duration is 40 ms and up. Valid gap duration is 30 ms (minimal for Japan)
and up to 70 ms minimum in Australia. So, my suggestion was to keep
defaults at their current values but allow to set minimal values to minimal
possible legal values (40 ms tone and 30 ms gap). My justification is that
DTMF is a legacy interop feature and it should be able reproduce any legal
DTMF string which can occur in the wild by modifying the JavaScript

Roman Shpount

On Thu, Jan 16, 2014 at 7:19 PM, Cullen Jennings (fluffy)

> This has been sitting on the editors todo list for a long time and I
> wanted to try and sort it out 
> The gap between DTMF digits is currently specified at 50ms. Long ago
> someone requested we change this to 40 ms.
> Does anyone remember why people wanted to make this change? Thought on if
> it should be 40 or 50?
> Thanks, Cullen
Received on Friday, 17 January 2014 00:43:38 UTC

This archive was generated by hypermail 2.3.1 : Monday, 23 October 2017 15:19:37 UTC