Distributed delay constrained multicast routing algorithm with efficient fault recovery

Existing distributed delay constrained multicast routing algorithms construct a multicast tree in a sequential fashion and need to be restarted when failures occur during the multicast tree construction phase or during an on-going multicast session. This article proposes an efficient distributed delay constrained multicast routing algorithm that constructs a multicast tree in a concurrent fashion by taking advantage of the concurrency in the underlying distributed computation. The proposed algorithm has a message complexity of O(mn) and time complexity of O(n) in the worst case, where m is the number of destinations and n is the number of nodes in the network. It constructs multicast trees with the same tree costs as the ones constructed by well-known algorithms such as DKPP and DSHP while utilizing 409 to 1734 times fewer messages and 56 to 364 times less time than these algorithms under comparable success rate ratios. The proposed algorithm has been augmented with a fault recovery mechanism that efficiently constructs a multicast tree when failures occur during the tree construction phase and recovers from any failure in the multicast tree during an on-going multicast session without interrupting the running traffic on the unaffected portion of the tree.