COMMUNICATION SYSTEM, DETERMINING METHOD FOR ALTERNATIVE ROUTE OF THE SYSTEM, AND RECORDING MEDIUM FOR RECORDING DETERMINING PROGRAM OF THE ALTERNATIVE ROUTE

摘要

PROBLEM TO BE SOLVED: To provide a communication system for setting and updating proper alternative routes in the standard network system of a 3rd GPP and for eliminating effectively generations of the congestions, to provide a determining method for the alternative routes, and to provide a recording medium for recording therein the determining program of the alternative routes. SOLUTION: In the communication system, a connection managing node for monitoring traffics on a communication network and for controlling its communication routes has a traffic-information monitoring means and has a means for communicating traffic-informations to the external. Also, each SGSN for relaying informations between each GGSN of an external gateway and each user terminal has a means for monitoring cost-metric informations in a public land mobile network and has a cost-metric-information communicating means for notifying cost-metric-information tables to external nodes. Further, each user terminal has an information-table receiving means for acquiring therefrom the informations of the notified states of the communication network from external nodes and has a communication-route controlling means for deciding optimum communication routes based on the acquired informations and for connecting each user terminal with the optimum communication routes.