Callback and Voicemail I believe is what he wants.
This is listed on the Trac TODO section:
82 #### Add VoiceMail
83 ********************************************************************
84
85
http://www.ecualug.org/?q=2006/12/12/co ... 10_minutos
86
http://forum.asterisk2billing.org/viewt ... =voicemail
87
88
89 You need to create the appropiated line for each extension at the voicemail.conf file. Add the following lines to your a2billing context to give your clients the voicemail feature:
90
91 Code:
92
93 [vmmain]
94 exten => *97,1,Answer
95 exten => *97,n,Wait(1)
96 exten => *97,n,VoiceMailMain(${CALLERID(num)}@default)
97 exten => *97,n,Hangup