Traffic monitoring in a network of PBXs

Monitoring traffic flow in a network of PBXs (private branch exchanges) of arbitrary size and configuration is studied. Two alternative monitoring architectures which differ primarily in the mode of generating call detail records (CDRs) are proposed. In architecture A the CDRs are generated in a manner similar to that now used for supporting billing functions. ln architecture B a single CDR is generated by making full use of common-channel signaling. It is shown that architecture B results in greatly reduced requirements for storage space and processing at the monitoring center, and in the transmission bandwidth required to deliver CDRs to the center. Algorithms that can be used with either architecture to provide both real-time and retrospective traffic monitoring are presented