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.

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

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