Algorithms for Precomputing Constrained Widest Paths and Multicast Trees

Abstract – We consider the problem of precomputing constrained widest paths and multicast trees in a communication network. Precomputing and storing of all relevant paths minimizes the computational overhead required to determine an optimal path when a new connection request arrives. We present three algorithms that precompute paths with maximal bandwidth (widest paths), which in addition satisfy given end-to-end delay constraints. We analyze and compare the algorithms both in worst case and through simulations using a wide variety of networks. We also show how the precomputed paths can be used to provide computationally efficient solutions to the constrained widest multicast tree problem. In this problem, a multicast tree is sought with maximal bandwidth (widest multicast tree), which in addition satisfies given end-to-end delay constraints for each path on the tree from the source to a multicast destination