Improved QoS-aware switching mechanism for PIM-SM protocol

PIM-SM (Protocol Independent Multicast - Sparse Mode) is a multicast routing protocol that uses one central node (which we refer to with the Rendezvous Point ¿RP¿) for all transmitters in a multicast group. It builds source-specific trees to the transmitters whose data rates exceed a predefined threshold. Investigations have been done to improve and provide an efficient mechanism for switching between the shared-based mode and source-based mode in order to limit some Quality of Service (QoS) such as end-to-end delay, bandwidth, etc. In this paper, we improve the switching mechanism proposed by [FD02]. To evaluate the performance of our improvement, two PIM-SM models (without a switching mechanism and with a rate based switching mechanism) are used as a reference for comparison. Our improved switching mechanism results in a lower network load compared to the standard switching mechanism and keeps the end-to-end delay within a predefined threshold. The additional control load overload is presented.