Echo( ) Echoes inbound audio back to the caller
Echo( )
Echoes audio read from the channel back to the channel. This application is often used to test the latency and voice quality of a VoIP link. The caller may press the # key to exit.
Returns 0 if the user exits with the # key, or -1 if the user hangs up.
exten => 123,1,Echo( )
exten => 123,2,Playback(vm-goodbye)