Optimum structures and growability of shared-buffer fabrics

Large ATM switching fabrics are frequently obtained by arranging more elementary switches in various ways. This paper presents results of our investigations on how these elements should be arranged to minimize the cost expressed by the number of elementary switches. The problem is not trivial if we consider fabrics that allow smooth growth from small to large number of ports. In this paper we consider a two-sided growable ATM fabric architecture using shared-buffer-based switching elements. The fabric is expanded by connecting additional basic fabrics to the existing structure by some interconnecting modules. In our investigations we have used the dynamic programming method, which is based on Bellman´s optimality principle. As the result, the comparison of the cost of various ATM switching fabrics is given