A Recording and Processing System for Accounting and Traffic Analysis on a Large PABX

A new facility for recording and subsequent computer processing of telephone calls has been developed at the Technical University of Norway. The equipment is intended for connection to a PABX of conventional electromechanical design. It is fully electronic and is based on cyclic scanning of up to 128 trunk-line circuits. The recording medium is digital magnetic tape and data are collected, arranged, and temporarily stored in a core buffer store before being transferred to tape. The central control unit of the equipment is based on wired logic with integrated circuits. Extension numbers are automatically identified by means of a Dimond ring encoder. The primary objective of the facility is the accounting of outgoing calls. However, it has proved to be very well suited for traffic data recording and analysis. The paper contains a description of the recording equipment and discusses further the applications for accounting and traffic analysis, of which a few examples are presented. A comprehensive treatment with emphasis on statistical presentation will be prepared for separate publication later.