I would recommend you use out-of-band DTMF based on RFC 2833.  In band DTMF is usually not reliable in short bursts.
 
Jerry


From: Dan [mailto:freeswitch-users@digitaldan.com]
Sent: Wednesday, January 13, 2010 10:02 AM
To: freeswitch-users@lists.freeswitch.org
Subject: [Freeswitch-users] Cisco media gateway and DTMF

Hi guys, I'm having an issue with DTMF detection from our cisco 5300 gateways.  DTMF detection has been working great when someone was manually inputing the digits (ie there are small pauses between the DTMF digits),  but when the other end is sending those digits from say a speed dial or programmed dial string and can send the DTMF digits one right after the other we start to drop one or more digits about 75% of the time.   

I upgraded to trunk this morning and have tried everything that was listed on http://wiki.freeswitch.org/wiki/RTP_Issues .  I have a pcap output of the SIP and RTP data, it looks fine to me, I can see the DTMF payloads coming as they should be.  Any ideas?  I would be fine sending or posting the pcap file to someone privately.

Thanks
Dan-