Route optimized nested mobility solution using PAT

Mobile computing is becoming increasingly important due to the rise in the number of portable computers and the desire to have continuous network connectivity to the Internet, irrespective of the physical location of the node. Mobile IP is an extension to IP that attempts to delineate the physical location of a mobile node with its assigned IP address. With the extension of mobility from a host to a network, the need to provide foreign agent services within a mobile network is gaining importance. Provision of foreign agent services within the mobile network is termed as nested mobility. With the use of normal Mobile IP, each level of nesting introduces additional overhead, thereby wasting network resources. In addition, nested mobility introduces routing issues known as "pinball routing". The authors propose a route optimization based solution to address the pinball routing problem and reduce the tunneling overhead over the Internet cloud. The proposed solution uses the concepts of port redirection to route traffic to a node within the mobile network. The proposed solution eliminates the need for tunneling between the nested mobile devices and their respective home network. Initial analysis carried out by the authors indicates a significant improvement in overall performance for the participating nodes.