[macro-stdexten]
exten => s,1,Dial(${ARG1},36)
exten => s,3,Goto(s-${DIALSTATUS},1)

exten => s-BUSY,1,GotoIf($[${ARG2}=NONE]?3)
exten => s-BUSY,2,Voicemail(b${ARG2})
exten => s-BUSY,3,Hangup

exten => s-NOANSWER,1,GotoIf($[${ARG2}=NONE]?3)
exten => s-NOANSWER,2,Voicemail(u${ARG2})
exten => s-NOANSWER,3,Hangup

exten => s-.,1,Goto(s-NOANSWER,1)

exten => a,1,VoicemailMain(${ARG1})
exten => a,2,Hangup

[incoming]
...
exten => s,10,Set(TIMEOUT(digit)=6)
exten => s,11,Set(TIMEOUT(response)=10)
exten => s,12,Set(LOOPCOUNT=0)
exten => s,13,Wait,1

exten => i,1,Playback(pbx-invalid)
exten => i,2,Set(LOOPCOUNT=$[${LOOPCOUNT} + 1])
exten => i,3,GotoIf($[${LOOPCOUNT} > 2]?t,1)
exten => i,4,Goto(s,13)

exten => t,1,Playback(pbx-transfer)
exten => t,2,Macro(stdexten,${DEFAULT},${DEFAULT})
exten => t,3,Hangup( )
...