Multicast Forwarding Using Multiple Gateways and Hash for Duplicate Packet Detection in a Tactical MANET

Simplified Multicast Forwarding (SMF) [3] provides an optimized flooding mechanism in MANET environments to efficiently propagate multicast packets. In order to be more useful in a broader range of scenarios, we need to be able to get multicast packets to and from fixed infrastructures. Gateways in MANETs are more complex than regular MANET nodes as they require both to join multicast groups on behalf of the MANET, as well as to forward multicast packets between networks. Multicast gateways are required to interoperate with other multicast routing protocols in the wired domain. In this paper we show that by using a hash function we are able to assign packets with a common unique packet identifier that is further used for duplicate packet detection. Using the hash function in conjunction with multiple gateways, we lower the traffic overhead, increase the packet delivery ratio, and make the protocol more resilient to network partitioning as well as independent to the number of gateways.