Implementing Mobile IP Routing in 4 . 3 BSD Unix : A Case StudyVineet Chikarmane

With increasing demands for mobility support in today's computing environments, routing packets to mobile hosts is a problem of considerable research and commercial interest. The introduction of mobility necessitates a change in the way routing is implemented in the Internet, and protocols to provide this routing eeectively and eeciently are under active consideration. Mobile IP, a protocol intended for TCP/IP networks in general and the Internet in particular, has received a great deal of attention. The Internet Engineering Task Force has been working towards the development of a speciication for Mobile IP. This emerging speciication formed the basis of our investigation. This paper describes the design, implementation, and performance evaluation of network layer modules to provide routing support for IETF Mobile IP in a 4.3 BSD Unix TM system. In particular, we have fully implemented the Home Agent and Foreign Agent functionalities speciied in IETF Mobile IP, and partially implemented the Mobile Node functionality required for mobility management. Decisions made during the design and implementation phases are discussed and defended. Our performance measurements provide evidence that the design and implementation are capable of comfortably handling the anticipated load imposed for the support of mobile hosts in the context of network technologies that are popular today, such as Ethernet.