Abstract: A telecommunication network includes a number of mutually coupled private branch exchanges to which are assigned respective storage locations for storing switching data and which include processors for determining the most favorable route in dependence on the stored switching data to a subscriber terminal arranged inside or outside the telecommunication network. In the network, an outgoing route from one of the private branch exchanges is led through one or more of the other private branch exchanges and/or through one or more other telecommunication networks.

Abstract: A communication system comprises a communications network coupled at least to a terminal unit. The communications network is coupled to a service device which comprises a switching center, a controller, and a data bank. The data bank contains at least a service logical program. A terminal unit generates a first parameter and a second parameter for sending as a single transmission to the service device. The controller extracts a service logical program from the data bank in response to the first parameter. The controller further controls the switching center in response to the second parameter based on the extracted service logical program.