Abstract: This invention relates to the use of a standard language and signal interface between a custom line card for connection to a corresponding arbitrary type terminal, and a switch. The line card is plugged into an interface unit which converts between the signals from the arbitrary type terminal and a standard set of signals for interfacing with the switch. The Bellcore TR303 standard is the preferred choice for communicating signals between the interface unit and the switch. The term terminal as used herein is very general and includes both simple (analog) and complex (video) telephone devices, as well as other types of customer premises equipment such as FAX terminals; it includes, for example a TV set-top box. Advantageously, only a small signal conversion program and table, and an interface card, need be developed in order to support a new type of terminal.