ORC: optimized route cache management protocol for network mobility

In this paper, we describe the Optimized Route Cache Management Protocol (ORC) as a network mobility protocol and evaluated it through experiments on a prototype implementation. ORC provides mobility transparency to a network regardless of network movements. Mobile network is a network that moves entirely. Typical examples for a mobile network are personal area networks (PAN) and networks inside vehicles. ORC is based on mobile IPv6 and is combined with the Internet routing mechanisms for network mobility management. ORC assigns a unique unchanging subnet prefix to a mobile network and notifies and maintains a mobile network's route called binding route (BR). A BR is an association between the prefix of the mobile network and a current available address known as care-of address in mobile IPv6. ORC allows interior gateway protocol (IGP) routers named ORC routers to cache a BR. ORC routers intercept packets destined to the mobile network and route them to the mobile network according to the BR. The BR must be updated as soon as the mobile network changes the care-of address by its topological position, employing constant BR exchange to ORC routers and temporary BR exchange to dynamically discovered ORC routers. Based on the experimental results, ORC is confirmed to provide network mobility and optimal communication in terms of route optimization. The evaluation shows that route optimization is required for network mobility to improve communication performance.