Optimized Smooth Handoffs in Mobile IP

Mobile IP provides mobility support for hosts connected to the Internet without changing their IP addresses. Route optimization strategies complement Mobile IP, to alleviate triangle routing, by informing correspondent hosts of the mobile host’s care-of address. In this paper, we propose further strategies that are compatible with route optimization and its security model. First, foreign agents buffer packets for a mobile host and send them to its new location when it leaves. Second, hierarchical foreign agent management reduces the administrative overhead of frequent local handoffs, using an extension of the Mobile IP registration process so security can be maintained. Duplicate packets due to buffer handover are eliminated with the cooperation of mobile hosts. Simulation results show substantial performance improvements in terms of throughput, registration overhead, lost and duplicate packets during a handoff, without restrictions on physical placement of foreign agents.