[Asterisk-Users] DTMF inband detection improvement

[Steve Blair]

Steve:

   Given this and the number of recent messages related to DTMF problems
can you add any thoughts on how to improve implementations?

    I too have problems correctly handling DTMF in my environment. In the
LAN /IP world DTMF works as expected to allow an IP phone user to
access my Asterisk based menu.

    Calls from the PSTN usually work as expected but occasionally someone
reports that pressing the keypad digits has no affect. Instead the timeout
clause is eventually hit and the caller is disconnected.

    Cell phone users cannot even use their phone keypad to respond to
prompts. They always timeout.

Thanks,Steve


Steve Underwood wrote:

> Hi Peter,
>
> If that is true, someone must have broken something. Not only does the 
> DTMF detector I wrote not care about small imperfections, it even 
> tolerates a dropped packet with the DTMF passes over a VoIP path (this 
> kind of tolerance was added a couple of years ago).
>
> Regards,
> Steve
>
>
> Peter Svensson wrote:
>
>> We have some problems with dtmf detection on our lines. We use E1 pris
>> connected to a TE405P. Mostly we see duplicated digits. Unless the 
>> signal is perfect and distortion free Asterisk sees the small 
>> imperfections as the end of the digit.
>>
>> We can provoke this problem from some of our office phones (when on 
>> speaker phone). Asterisk is more or less the only place we see this 
>> problem.
>>
>> Peter
>>  
>>
>
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