Interfacing

Abstract

Any telephone exchange has to interface with its existing environment. Hence, there will always be the need for adaptive engineering for specific exchanges. The design approach taken must recognize these needs and allow the system to adapt gracefully to it by modifications of software and/or hardware. In particular, it must be able to adapt to varying requirements for line and trunk signaling and two-, three-, or four-wire trunks. These trunks will interconnect with existing direct and indirect control exchanges both public and private.