A tree switching protocol for multicast state reduction

We propose a new tree switching protocol (TSP) to reduce multicast routing states required for a forest of multicast trees. The protocol accomplishes this goal by selecting a base multicast tree and “switching” other multicast trees to the base tree. This results in more overlapping among the multicast trees and a net reduction in multicast state. A further reduction in the state is possible by applying state aggregation to the overlapped tree branches. Simulation results show that the tree switching operation alone could result in a very significant state reduction. The TSP is a distributed protocol running on top of any protocol independent multicast routing protocols. It is also loop-free and very efficient