I've noticed that I often hear DTMF tones while using my PAP2T. When I look at what was logged to syslog I see something like this:
Jun 9 16:24:01 AVT Tx 5 start
Jun 9 16:24:01 AVT Tx 5 end
Jun 9 16:24:01 ++++ duration 400 too short, avt packet dropped
Are there some settings that would make this less likely or perhaps some newer firmware (currently 5.1.6)?