Detect Busy tone in Analog Lines

Hi. When I dial via FXO port,How can I make the Asterisk detect “Busy tones” and then Wait(5) and try to call again?

What application listen for busy tone and then jump to the next priority?

Thanks

run core show applications and search if one of them meet you goal.

[quote] ChanIsAvail() Indicates whether the specified channel is available.

Check the availability of Dahdi/1 and Dhadi/2:
exten => 123,1,ChanIsAvail(Dahdi/1&Dhadi/2,j)
; As an exception, using priority jumping, because we want to announce
; something to the caller if no channel is available

; at least one channel is available - dial this channel:
exten => 123,2,NoOp(${AVAILORIGCHAN} is available)
exten => 123,3,Dial(${AVAILORIGCHAN}/123456)

; if the call goes to priority 102 landen, neither Dahdi/1 nor Dahdi/2 is available
exten => 123,102,Playback(all-channels-busy)
[/quote]
the-asterisk-book.com/1.6/applik … avail.html