Performance Analysis of Mobile IP Extended with Routing Agents

Mobile IP is the proposed standard for IP mobility support. A mobile node registers its current location with its home agent when it moves across IP subnets in a foreign network. When a mobile node is far away from home, registration with its home agent can cause a long handoo delay. We have extended Mobile IP with routing agents. The routing agent of a mobile node serves as the current location of the mobile node at the home agent, and handles local movements of the mobile node directly through local registrations. Registrations with the home agent can change the routing agent of a mobile node but are performed much less frequently and do not involve changing the point of network attachment of a mobile node. This paper analyzes the performance of Mobile IP and the extension with routing agents in terms of registration cost, handoo delay, and packet tunneling cost. The results show that routing agents reduce the overall registration cost and the handoo delay signiicantly with a slight increase of the tunneling cost for each packet when a mobile node is not close to home. Both the handoo delay and the increase in tunneling cost are bounded, independent of the distance of a mobile node from its home agent. When a mobile node is close to home, Mobile IP is more eecient and is the special case where the routing agent coincides with the home agent.