Implementation and Performance Evaluation of Route Optimization in Mobile IP
Carleton University, Ontario, Canada. November 2001.

With the convergence of two technological developments, wireless communication and compact computer devices, mobility support in networks is more desirable than ever. IETF provides two approaches to support the mobility in the current Internet infrastructure. They are mobile IP and Mobile IP with Route Optimization, both of which introduce new functional entities, the home agent, and the foreign agent, into the Internet. The triangle routing existing in Mobile IP is a big defect in terms of resource consumption and performance. Route Optimization overcomes the triangle routing in basic Mobile IP but introduces more security requirements. In order to investigate performance of Route Optimization, we explored different ways to implement Mobile IP with Route Optimization and chose user space approach by C++ under Linux platform, evaluated the performance and provided our enhancement to the Route Optimization draft. We obtained quantitative efficiency evaluation results. Our conclusion is that user space implementation is acceptable and a desirable way to implement Route Optimization. The efficiency gain of Route Optimization will depend on the relative location of the three entities: the mobile node, the home agent and the correspondent node as well as the quality of communication links between the three entities. In most case, the Route Optimization efficiency gain is great and can achieve 17 times in terms of throughput as compared to basic Mobile IP, at the mean time, only 3% losses in terms of throughput as compared to plain IP. To solve deployment difficulty in the plentiful correspondent nodes, we proposed a Binary Exponential Backoff Algorithm (BEBA) to relieve the home agent burden while a correspondent node does not equipped with Route Optimization functionality. Our work provides a valuable sample of the implementation of Route Optimization and gives out quantitative performance enhancement in Route Optimization. It is a useful work for verifying Route Optimization draft and future mobility deployment in the Internet.