Performance Comparison of CBT and PIM Multicast Routing Protocols over MPLS Networks

Multi-protocol label switching (MPLS) is a promising cutting-edge technology for advanced forwarding of IP packets. Better performance of multicast routing in large-scale networks is expected when it is implemented over MPLS. In this paper, we simulate core-based tree (CBT) multicast routing protocol over MPLS-based networks using NS2, and compare its performance with protocol-independent multicast-sparse mode (PIM-SM). Simulations are performed for different network topologies with various group sizes using a modified version of the MPLS Network Simulator (MNS). Results reveal that as the number of source nodes increases CBT gives better performance than PIM-SM in terms of routing table size, join time, and total hop count. On the other hand, PIM-SM has less end-to-end delay than CBT