Network analyzers (NAs) monitor respectively corresponding communication lines through which Voice over Internet Protocol (VOIP) data streams are transmitted. A network troubleshooting center (NTC) communicates with the NAs to provide quality of service statistics for data streams transmitted through...http://www.google.de/patents/US7817567?utm_source=gb-gplus-sharePatent US7817567 - Troubleshooting a specific voice over internet protocol (VOIP) telephone call transmitted over a communications network
