Sip DTMF digit "extension"

We are having issues with a carrier when sending DTMF digits. Sometimes when we dial too fast (asterisk 1.4) not all digits go through. This is with one voip provider only and it’s an issue on their side.

How can we extend rfc2833 to wait 1/2 of a second before sending out the next dtmf digit pressed?


Try setting featuredigittimeout = 1000 in features.conf

Unfortunately this made things worse
Anything else I can do?