Methods and apparatus for controlling access to toll free telephone service

摘要

A system (10) for controlling access to communications lines (30) is disclosed. The system includes a personal device (12) and a central device (16). The personal device (12) includes a communications link address circuit embodying a plurality of addresses (44), an algorithm circuit (42), a processor (50) and a transmitting module (22). The processor (50) selects an address in accordance with the algorithm which is transmitted by the module (22). The central device (16) has a selection circuit (60) which designates one of the communication lines (30), retrieved from a candidate circuit (62), as an accessible link in accordance with the algorithm.