Routing in IP network based on codec availability and subscription reference

摘要

(57) Abstract The communication system (36) and method (60 and 80), through core network (24), offer service to the member who possesses the dispatch network (14) which is communicated with arrival network (32). Core network (24), in order to transfer calling mutually, conforms, includes the plural external gateways (40, 42 and 44) where each one at least has had one codec (50, 52 and 54). The communication system (36) includes the network node (37) which, processes the calling request from the member who possesses specification codec type here, as for the available gateway (40, 42 and 44) ranking is done to attach on the basis of gateway codec availability, core network (24) in order to transfer calling as a ranking function, has conformed. The above-mentioned method includes with the step where the 1st node (37) selects one of several external gateways (40, 42 and 44) inside core network as available as a function of the codec (50, 52 and 54) which is decided in step and the gateway which transmit codec type of calling request and member to the 1st node (37) inside core network (24). As for the 1st node (37), it can investigate the 2nd node (43) inside the core network (24) for the information which shows the available gateway inside core network (24).