DTMF Echo Test
From KlavoWiki
Just like an Echo Test the DTMF Echo Test will respond with the key that you have pressed. The dial plan below is based on Festival. If Festival is not installed the Festival lines can be removed.
;DTMF Test exten => 13,1,Wait(1) exten => 13,n,Playback(beep) exten => 13,n,Read(digito,,1) exten => 13,n,SayDigits(${digito}) exten => 13,n,GoTo(13,2) exten => 13,n,HangUp