The Implementation of Prepaid Services and Billing System over VoIP Networks

[[abstract]]Due to the low cost and the convenience of Internet, VoIP services are the best choice to substitute for fixed-networks and mobile phones. The profit of prepaid service in mobile phone market is continuously increasing. Therefore, with the integration of the two advantages in VoIP service and prepaid service (i.e. the low cost of VoIP and the controlled fee of prepaid service), VoIP prepaid service is expected to be the main trend in the future. The purpose of this thesis is to implement VoIP prepaid services and billing system by using open-source software. Experimentations are conducted showing that our system can accommodate 400 calls per second without loss. If the bottleneck component is moved to a standalone server, this number is nearly doubled. The result of this thesis can provide guidelines for small or medium firms, universities, colleges and companies to install a VoIP system with very low cost