Improvements in or relating to telecommunication systems

1,063,114. Automatic exchange systems. STANDARD TELEPHONES & CABLES Ltd. Nov. 6, 1964, No. 45299/64. Addition to 1,040,833. Heading H4K. In a system of the kind described in the parent Specification which employs independent signalling circuits for the setting up of interexchange calls, the originating exchange includes a library of auxiliary signals from which items are selected for transmission as required. Such items may indicate, for example, the origin of the call and/or the class of calling party, the exchange at which the called number is to be examined next, the presence or otherwise of echo-suppressors, the number of links involved.