A distributed, loop-free, shortest-path routing algorithm

Abstract

A new distributed algorithm for the dynamic computation of the shortest paths in a computer network is presented, validated, and analyzed. According to this algorithm, each node maintains the lengths of the shortest path to each network destination and a feasibility vector. Update messages from a node are sent only to its neighbors; each such message contains one or more entries, and each entry specifies the length of the selected path to a network destination, and whether the node requires internodal coordination. The algorithms extends the Jaffe-Moss routing algorithm by allowing nodes to choose new successors to destinations with no need for internodal coordination if the new successors are considered to be at most at the same distance as the current successors. The algorithm is shown to converge in a finite time after an arbitrary sequence of topological changes, to be loop-free at every instant (independently of the delays in the network) and to outperform other previously proposed loop-free, shortest-path algorithms from the standpoint of combined temporal, message, and storage complexities.< >