I did many a2billing based projects,I make the a2billing system can do
1.callingcard
2. callback ( I integrate a2billing callback with callfile,which make callback reliable(it can callback 3 times until the caller get the callback calls) and accurate billing,currently a2billing cannot give accurate prepaid time control for a2billing,I solve it by using extra-fee )
3. callshop service or vonage-like service
4. followme service
5. one AD service based on a2billing, the scenario is :
a. customer dial in,he'll hear:
your call is sponsored by ABC company,please enter destination number
b. after enter destination ,the system will allow him make a 10-minutes (predefined or calcuated) free call,when he is waiting for call,he will hear the company's advertisements
c. the advertisment client can view his usage via WEB UI,and he can upload his adverisements voice files
d. the system support many advertiment clients of course
e. even SMS callback service
many asterisk based solution customerization
for my all info,please see
http://voip.myoutsource.net
my email:
[email protected]