[Asterisk-Users] GSM ISDN gateway to quadbri NT port under bristuffed Asterisk - where to set gain (I have unreliable inband dtmf recognition )?

[Steve Underwood]

Peter Svensson wrote:

>On Tue, 21 Jun 2005, Leandro Morgado wrote:
>
>  
>
>>Steve Underwood wrote:
>>    
>>
>>>Robert Rozman wrote:
>>>      
>>>
>>>>I'm getting unreliable dtmf recognition (it works fine for 4-5
>>>>digits, errors (duplicates) on more), when transferred inband from
>>>>gsm gateway to NT port of quadbri under bristuffed Asterisk.....
>>>>        
>>>>
>
>We get these quite often. If there is any line noise asterisk will 
>interpret it as the end of a digit and then detect the same digit again. 
>We are connected to the pstn via isdn. The problem is with calls where the 
>dtmf tones are a bit unclean, i.e. too much energy is in the overtones. 
>Clean dtmf tones seem to be much more resistant to line noise.
>
>Out other systems are more accepting of slightly off-spec dtmf tones.
>  
>
People often make claims like this, but never seem able to back them up. 
They usually turn out to be a wildy set receive gain, wrong codecs, or 
something equally screwed up. Can you quote chapter and verse for a real 
problem?

The DTMF detector in * is one of the most robust around.

Regards,
Steve