A SCHEME TO SUPPORT IP MULTICASTING IN MOBILE IP

Abstract

There are two methods to transmit IP multicast packets in a mobile environment. These are the Bi-Directional Tunneling scheme and the Remote Subscription scheme as stated in RFC 2002 [1]. There are problems with these methods. In particular, duplication of multicast packets known as the Tunnel Convergence and Tunnel Divergence Problem can occur in the Bi-Directional Tunneling scheme. Duplication or loss of multicast packets due to network latency can occur in the Remote Subscription scheme. Besides these problems, there is no security measure to ensure that no bogus MN may join and leave a multicast group. This thesis proposes a new scheme called the Multicast Support for Mobile IP (MSMIP) to prevent duplication and loss of multicast packets by introducing a new entity called a CORD to monitor the flow of multicast packets. Rather than implementing ingress filtering, a security measure is incorporated by having a MN authenticated by its HA before it joins or leaves a multicast group. The scheme is interoperable with the Mobile IP base protocol and is independent of any IP multicast routing protocol. An implementation of the scheme is described and its performance in a small test-bed network is also studied.