You can test DTMF receiving by Test.exe under ShCti. 1)make inbound call to Test.exe then Press SsmPickup while the status is Ringing. 2)it will turn to Talking.then all the detected DTMF will present at –DtmfRcvBuffer. You may talk,press DTMF or make voice to check if there is DTMF misdetecting,missing.