A Proxy-Based Integrated Cache Consistency and Mobility Management Scheme for Mobile IP Systems

In this paper, we investigate a proxy-based integrated cache consistency and mobility management scheme in mobile IP systems. Our scheme is based on a stateful strategy by which cache invalidation messages are asynchronously sent by the server to a mobile host (MH) whenever data objects cached at the MH have been updated. We use a per-user proxy to buffer invalidation messages to allow the MH to disconnect arbitrarily and to reduce the number of uplink requests when the MH is reconnected. Moreover, the MH's proxy serves as a gateway foreign agent (GFA) as in the MIP Regional Registration protocol to keep track of the address of the MH in a region. The proxy migrates with the MH when the MH crosses a regional area. We identify the optimal regional area size under which the overall network traffic cost, due to cache consistency management, mobility management, and query requests/replies, is minimized. We demonstrate that the integrated cache consistency and mobility management scheme outperforms both no-proxy and/or no-cache schemes in Mobile IPv6 environments.