[Asterisk-Users] DTMF when using g.729

[Leo Ann Boon]

Paul Hewlett wrote:

>   There was a discusson on this list - something about DTMF settings when not 
>using alaw/ulaw having to be 'inband' and not 2833 or SIP INFO ?
>
>  
>
I think you have gotten it backwards. You need RFC-2833 or SIP-INFO if 
not using alaw/ulaw. Most compression will remove certain frequencies 
from the signal. As a result there may not be enough spectral energy 
left to allow the DTMF detector to work correctly.

Leo.