CONCURRENT COMMUNICATION IN HIGH-SPEED WIDE AREA NETWORKS

A performance metric called receptivity is introduced for quantifying the degree of concurrent communication possible in high-speed wide area networks (WAN's). Given a stochastic demand pattern model, receptivity is defined to be the probability that all requested connections can be established concurrently. Because calculation of the exact value of receptivity is shown to (generally) have an exponential complexity, an analytic estimate for its value is derived. The derived estimate is dependent on network parameters such as the number of links, link capacity values, and a weighted hop distance metric (which depends on the topological structure of the network and its relationship to parameter values of the stochastic model for the demand patterns). The derived estimate for the proposed metric compares reasonably well with simulated values for several asymmetric topological structures ranging from planar meshes to random graphs. The utility of the estimate is twofold. First, it can be computed quickly, i.e., in polynomial time. Second, its simple analytic form provides the network architect with insight into some of the inherent limitations and consequences associated with topological design choices for high-speed WAN's.