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

Re: Min DTMF Gap

From: Gunnar Hellstrom <gunnar.hellstrom@omnitor.se>
Date: Sat, 18 Jan 2014 09:01:27 +0100
Message-ID: <52DA34D7.1010406@omnitor.se>
To: Roman Shpount <roman@telurix.com>
CC: "Cullen Jennings (fluffy)" <fluffy@cisco.com>, Mike Johns <m.johns@commsalliance.com.au>, "public-webrtc@w3.org" <public-webrtc@w3.org>
On 2014-01-18 00:23, Roman Shpount wrote:
>     I now suggest that we follow the ETSI standard and set 70 tone 70
>     gap fixed with no adjustment possibility.
> This will be extremely undesirable. First of all, you do need to 
> generate long DTMF tones (there are IVR features that are activated by 
> DTMF tone of half a second or longer). Second, and this was the 
> original reason for my request to Cullen to change these parameters, 
> there are a lot of legacy interop scenarios with opposite requirements 
> (some need long tones, some need short tones, some need gaps of the 
> right minimal length). Let the defaults be safe for typical DTMF use 
> case, but let the application developer be able to generate any legal 
> DTMF tone if it is needed. If app developer decides to change these 
> optional settings, it is his responsibility to make sure that they 
> will work for his use case. There is no point to reinvent DTMF 
> standards here -- let's set the minimums to currently accepted minimums.
If you see a need for settings, I do not mind having that possibility.
The 40 ms minimum is for detection at the receiving end, so it would be 
logical to set the possible transmission timing minimum slightly higher.

Received on Saturday, 18 January 2014 08:02:06 UTC

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