A QoS-Aware Switching Mechanism Between The Two Modes of PIM-SM Multicast Routing Protocol

PIM-SM is the only deployed intra-domain multicast routing protocol that builds both shared and source-based trees. However, it does not provide an efficient mechanism to switch between the two modes. The PIM-SM switching mechanism proposed in this paper aims to improve both network and receivers requirements. It is a coordination-based mechanism in the sense that all concerned receivers contribute to the switching decision and not only the receiver requesting the switching. Furthermore, the mechanism uses information about the temporary available network resources provided by an underlying QoS-based unicast routing protocol or using periodic switching experiments to decide when to switch between the two modes. Simulation results show that our mechanism achieves the inter-receiver switching fairness and that its integration in PIM-SM provides efficiently its original intentions.