INTERWORKING FUNCTION SELECTION SYSTEM IN NETWORK

PROBLEM TO BE SOLVED: To disclose the interworking function selection system for an online type network. SOLUTION: A foreign network 62 includes a foreign mobile exchange center 66 containing registered servers on service, and a home network 70 includes a home mobile exchange center 72 containing home registration servers and pluralities of unassigned home interworking functions. A 1st end system is a subscriber with respect to the home network and operated in the foreign network. The 1st end system includes an end registration agent to generate a registration request, the end registration agent sends a registration request to the home registration server through the registration server and the home registration server includes a module to select an active home interworking function among pluralities of unassigned home interworking function 72 based on the registration request.