The authors discuss some basic issues relevant to the policing function in asynchronous transfer mode (ATM) networks. The problem of controlling the source peak rate in the presence of the cell delay variation introduced in the customer premises network is considered. A model for analyzing the cell delay variation is presented, under the assumption of a constant bit rate source multiplexed with a Poisson stream. On the basis of the distribution obtained, the relevant parameters of two policing devices (the jumping window and the leaky bucket) are dimensioned. The numerical results lead to the conclusion that the leaky bucket allows a tighter source control then the jumping window.>

This paper deals with the definition of a class of NxN interconnection networks called Parallel Delta Network (PDN). For this class of networks the non-blocking conditions are given. In particular, by means of the graph colouring technique, it has been proved that the minimum number of Delta subnetworks (L) necessary to provide the non-blocking property is L=nfS/21-1 where n is the size of the basic switching element and S the number of stages required by an NxN Delta network. A routing algorithm for the establishment of any permutation has been defined. \nIt operates for any value of n and shows a polynomial time \ncomplexity equal to O(N3/2). Moreover, in case of the setup \nof a single connection request, this algorithm assures a \ntime complexity equal to O(VN). This property makes it \nwell suitable to an asynchronous telecommunication \nenvironment.