A growable shared-memory based multicast ATM switch

This paper presents an ATM switch that fulfils the architectural and service requirements of large-scale ATM switches. The proposed network is based on a 3-stage Clos network, with shared-memory ATM switches at the input and output stages to provide optimal cell loss and delay performance. The modularity of the Clos architecture means that the network is inherently growable and has a high level of fault-tolerance. The network uses small sized shared-memory switches, so that the network can be scaled to large sizes without any technological constraints. The proposed network can support multicast traffic because of the multicasting functionality within shared-memory switches. Unlike other Clos based networks, this paper proposes a simple distributive routing algorithm for any sized network. Distributive multicasting allows multiple multicast cells to be routed simultaneously through the network. Various network configurations are simulated for their cell loss and cell delay performance. The resulting cell loss rate in the proposed network is well below that of the completely-shared ATM switch and the multicast cell delays are drastically improved