Optimum routing system

A coupled data network comprising:

• a foreign network that includes a base station and a foreign mobile switching center with a serving registration server, the base station including an access hub with a serving inter-working function;
• a home network that includes a home mobile switching center with a home registration server and a home inter-working function;
• and
• an end system subscribed to the home network and operating within the foreign network, the end system including an end registration agent to form a registration request, the registration request including and indication of a desired communications network having a desired communications server, the end system sending the registration request to the serving registration server, the serving registration server including a first module to process the registration request and to determine an optimum route between the desired communications server and one of the home inter-working function and the serving inter-working function, the serving registration server further including a second module to send to the home registration server the registration request with a first appended indication that the serving registration server has determined that the optimum route is between the serving inter-working function and the desired communications server and a second appended indication that route optimization is preferred.

A method for optimizing routing in a coupled data network wherein the coupled data network comprises a foreign network that includes a base station and a foreign mobile switching center with a serving registration server, the base station including an access hub with a serving inter-working function, a home network that includes a home mobile switching center with a home registration server and a home inter-working function, and an end system subscribed to the home network and operating within the foreign network, the end system including an end registration agent to form a registration request, comprising the steps of:

• generating a registration request at the end system, said registration request including an indication of a desired communications network having a desired communications server;
• sending the registration request from the end system to the serving registration server;
• processing the registration request in a first module in the serving registration server to determine an optimum route between the desired communications server and one of the home inter-working function and the serving inter-working function;
• linking the serving inter-working function to the desired communications server when the first module determines that the optimum route is between the serving inter-working function and the desired communications server.

A method for optimizing routing in a coupled data network wherein the coupled data network comprises a foreign network that includes a base station and a foreign mobile switching center with a serving registration server, the base station including an access hub with a serving inter-working function, a home network that includes a home mobile switching center with a home registration server and a home inter-working function, and an end system subscribed to the home network and operating within the foreign network, the end system including an end registration agent to form a registration request, comprising the steps of:

• generating a registration request at the end system, said registration request including an indication of a desired communications network having a desired communications server;
• sending the registration request from the end system to the serving registration server;
• determining whether the serving inter-working function or the home inter-working function is closer to the desired communications server;
• instructing the serving inter-working function to establish a connection to the desired communications server when the serving inter-working function is closer to the desired communications server than the home inter-working function;
• informing the home registration server that the end system is being served by the serving inter-working function and the desired communications server.