1. The document discusses the design of a prototype VoIP billing system to record call details for Internet Telephony Service Providers.
2. It analyzes the rate schemes used by TELKOM and the time processes involved in generating Call Detail Records in the VoIP billing system server.
3. The author implements the TELKOM rate schemes in the designed VoIP billing system and analyzes the time taken to process CDRs for local, inter-local, and multi-operator calls.