Hello ,
I am doing payment system integration for a2billing system
Creating new customer interface and PBX features:
VoiceMail;
Conference;
FollowMe ( +RingGroups );
Call Queues processing ;
Calling Cards advanced features ( recharge by phone using IVR and credit card in file)
Examples:
http://voiplatinum.com.mt/ ( http://voip.voiplatinum.com.mt/customer/ )
https://voip.organizzit.com/ ( https://voip.organizzit.com/ )
http://customer.ariacallingcard.com/
http://customer.vivolines.com/
http://5.199.136.223