A scalable, dynamic multicast routing algorithm in ATM networks

In this paper, we present a scalable dynamic multicast routing algorithm based on a dynamic Steiner tree approach. First, we analyze a hierarchical multicast routing algorithm which introduced the use of core nodes in each peer-group to support multicasting under the private network-network interface (PNNI) framework. Based on this analysis, we conclude that finding near-optimal multicast trees in each peer-group is important. Our proposed algorithm produces improved results by computing better multicast trees within each peer-group. This scheme also eliminates the dependency of core node selection, on the quality of overall multicast tree generated. We compare the two schemes based on simulations on several randomly generated graphs of size ranging from 115 to 170 nodes. Based on these simulations, we show that our algorithm performs 35% better than the hierarchical algorithm. Our algorithm is scalable, allows incorporation of fault-tolerance and can easily be extended to incorporate a QoS criterion in routing.