I have use alas channel with loopback alsa device. I have other application which will be
send via alsa channel DTMF code.
I have try simple script which mplayer play DTMF and send to input device in alsa channel
I have in extensions.conf
exten => 1234,1,Dial(SIP/2001,30)
exten => 1234,n,Hangup()
I have send DTMF 1234 to input device defined in alsa.conf but asterisk did not dial to phone SIP 2001
I try to find where is problem and question is that is possible decode DTMF codes via alsa channel to dial ???