I set up my dialplan to branch if busy:
exten => 100,1,Dial(SIP/RedStapler,20)
exten => 100,2,VoiceMail(u100@default)
exten => 100,3,Hangup()
exten => 100,102,VoiceMail(b100@default)
exten => 100,103,Hangup()
Behind extension 100 is an XLite softphone. I found that in my installation, branching to prio 102 takes place if unavaible, prio 2 is executed when busy. Opposite to my documentation and the way the diaplan is set up! I am wondering if this is a problem with the XLite phone signalling the status wrong, a bug in Asterisk (1.0.9), or an error in my documentation, or even a combination. Unfortunately, I do not have a hard SIP phone (yet, still looking) for verification, and the extensions.conf file supplied by the samples uses a different method of branching. Couldn’t find anything in the forum either.