exten => _X.,1,Set(NUMERO=${EXTEN})
exten => _X.,n,Dial(IAX2/user:senha@172.16.74.20/${EXTEN},60,tT)
exten => _X.,n,NoOp(${DIALSTATUS})
exten => _X.,n,Goto(ds-${DIALSTATUS}|1)

exten => ds-CHANUNAVAIL,1,Dial(DGV/G1/${NUMERO},60,tT)
exten => ds-NOANSWER,1,Hangup()
exten => ds-BUSY,1,Busy()