Advanced VoIP Billing Enterprise Edition is for large sized Internet Telephony Service Providers (ITSPs) providing carrier grade VoIP services. They require enterprise level of reliability, backup strategies and scalability in addition to having a more complex business model. A carrier grade ITSP provides multiple services by having multiple E1's, multiple PoP's (Points of Presence) dealing with multiple originators and terminators and needs a fail safe, redundant and round the clock reliable service. More complex business models include an Agent's network, multilevel marketing, multiple languages, more complex rate plans, progressive billing, peak/off peak hours, online credit card charging etc. in addition to basic prepaid and postpaid VoIP services.