Approximation for overflow moments of a multiservice link with trunk reservation

In this paper we propose an approximation for individual overflow moments of a multiservice link with differing arrival rates, capacity requirements and mean holding times, where trunk reservation is used. The approximation is a generalization of Roberts’ well-known approximation for individual blocking probabilities of a multiservice link to higher moments. It can be computed very efficiently. The quality of the approximation for the second moment (variance) is comparable to Roberts’ approximation for the individual blocking probabilities. Thus the results provide an efficient algorithm for computing the two moment characterization of the individual overflow streams and hence can be used for the design and analysis of circuit switched alternate routing networks with trunk reservation links.