Parallel GRASP algorithm with delay and delay variation for core selection in shared tree based multicast routing protocols

Many multicast routing protocols has proposed to support efficient multimedia application, PIM-SM and CBT protocols remain the most used multicast routing protocol; they propose using a Shared Tree ST to forward multicast packets. The prime problem concerning ST construction is to determine an optimal multicast router in the network as root; this problem is called Core selection. This problem influences the multicast routing tree structure, and therefore influences performances of the multicast session and multicast routing scheme. Determination of a best core position is an NP complete problem, first proposed by Wall, which needs to be solved with a heuristic algorithm. In this paper we propose a new Core selection algorithm based on Parallel GRAS Procedure and new CMP fitness function. 2DV-PGRASP-CR selects Core by considering cost, delay and delay variation functions and can be easily integrated to bootstrap RP protocol used by PIM-SM and CBT. Simulation results show that good performance is achieved in multicast cost.