A real-time telephone call monitoring, rating, and response system including real-time interfaces and switching centers that create and maintain in-process call detail records for on-going telephone calls. The real-time interfaces are accessed by a real-time monitoring unit in a billing system. The billing...http://www.google.fr/patents/US6226364?utm_source=gb-gplus-shareBrevet US6226364 - Method and system for providing prepaid and credit-limited telephone services
Method and system for providing prepaid and credit-limited telephone services
