Configuring sessions in programmable networks

The provision of advanced computational services within networks is rapidly becoming both feasible and economical. We present a general approach to the problem of configuring application sessions that require intermediate processing by showing how the session configuration problem can be transformed to a conventional shortest path problem for unicast sessions or to a conventional Steiner tree problem for multicast sessions. We study both a capacity-constrained version of the problem and an unconstrained version and show, through a series of examples, that the method can be applied to a wide variety of different situations. Particularly, we show how to extend Dijkstra's shortest path algorithm for use on the constrained version, and show that this approach can make significantly better use of network resources. (C) 2002 Elsevier Science B.V. All rights reserved.