Data incorporated in call detail records (CDR), obtained from network switches, are subjected to processing by a statistics engine which maintains separate counts for CDR events relating to certain calls, such as 800 number and 900 number calls. Such events, such as attempted calls, completed...http://www.google.es/patents/US5768352?utm_source=gb-gplus-sharePatente US5768352 - Generalized statistics engine for telephone network
Generalized statistics engine for telephone network
