Realization of Aggregated Multicast with Lagrange Relaxation Algorithm

When there are large numbers of groups in the network, the state scalability is one of the most critical issues that delay the deployment of multicast. Forwarding state will increase linearly with the growth of the number of groups. Growing number of forwarding state entries means more memory requirements and slower forwarding process. Aggregated Multicast is a new technology, which aims to force multiple multicast groups to share one distribution tree in an intra-domain. In this way, the number of trees in the network may be significantly reduced; consequently, forwarding state is also reduced, and thus the performance of Multicast network can be highly heightened. In this paper we use Lagrange Relaxation Algorithm to solve Aggregated Multicast. The simulation results show that Lagrange Relaxation Algorithm is good in increasing aggregation degree and multicast state reduction ratio. The more multicast groups in the network, the higher aggregation degree, the lower the reducing rate of forwarding state.