I am almost there but not quite. I have simpleusb working, levels set. Commands like *80 *81, etc work. But I can't seem to connect to anything. If I go into asterisk shouldn't I be able to trace the call progress? I see nothing but digits entered and then a hangup. Help me to understand the path of incoming radio DTMF. SimpleUSB picks it up as defined in rpt.conf. In rtp.conf the node is defined - [27225] ; Change this to your assigned node number ;rxchannel=Radio/usb27225 rxchannel = SimpleUSB/usb duplex=1 context = radio etc....... Then in iax.conf there is the radio stanza ; Incoming radio connections [radio] type=user disallow=all allow=g726aal2 allow=gsm codecpriority=host context=radio-secure transfer=no Then in extensions.conf [radio-secure] exten => 27225,1,rpt,27225 Where does it get passed to any number processing? I have made only my node data and minor changes to these files. I did install an iaxrpt stanza in iax and extensions.conf and I can connected iaxrpt from my windows computer to the radio with audio both ways. 73 Doug WA3DSP http://www.crompton.com/hamradio