LEAST COST ROUTING METHOD ACCORDING TO INFORMATION TRANSFER CAPABILITY OF CUSTOMER PREMISES EQUIPMENT

摘要

ISDN subscriber line interface circuits of a switching system serve customer premises equipment of different information transfer capabilities. Least cost routing data and corresponding digit conversion data are stored in a memory, with the routing data indicating least cost outgoing routes through an ISDN network. These data are retrieved from the memory according to the called party number and information transfer capability field of a call setup message received from a calling party. The called party number is then converted according to the retrieved digit conversion data, and an ISDN trunk circuit is selected according to the retrieved least cost routing data. A connection is established between the originating ISDN SLIC and the selected ISDN trunk circuit, and the converted called party number is transmitted through a signaling channel to the ISDN network.