SIMULATION STUDY OF MOBILE IP PROTOCOL

Abstract

With the proliferation of compact and portable computers, mobility of hosts connected to a network is becoming an important issue. This work simulates and studies some performance issues of a protocol which supports mobility of hosts connected to the Internet. The protocol relies on Mobility Support Routers (MSR) which provide continuous network connectivity to the mobile hosts. These MSRs are points of connectivity of current static network where mobile nodes attach themselves. As a mobile node moves in the net, it attaches and registers itself with its home subnet via the nearest MSR (which is termed as home agent or foreign agent depending on the subnet to which the mobile node visits) and thus acquires a new temporary IP address. Thus two MSRs know the current location of the mobile node- the Home Agent and the Foreign Agent. The home agent intercepts datagrams destined to the permanent IP address of the mobile node and tunnels them through the static net to the foreign agent, which hands the datagrams to the mobile node. This protocol uses transparent routing of IP packets to the mobile hosts while using the mobile host's permanent IP address. It does not require any change in a fixed host that communicates with mobile hosts. A modification in this protocol has been suggested wherein packets intended for the mobile host travel along shorter routes in certain situations. The Mobile IP and Modified scheme are compared and it is shown that the later performs better. The Program is implemented in C language and runs on UNIX platform on a DEC ALPHA AS 400 server.