A high-performance ATM switch based on modified shuffle-exchange network

This paper presents an output buffering ATM switch, called modified shuffle-exchange network (MSN) that is obtained by inserting a connection pattern just after every other shuffle-exchange stage. The purpose of modifying a shuffle-exchange network by inserting a connection pattern is to reduce significantly the number of its internal conflicts. Each link of every other stage of MSN has a filter to route successful packets to their destinations. Instead of employing the traditional destination tag routing scheme on MSN, we developed a fast destination tag routing scheme, called FDR, for MSN. In the traditional destination tag routing scheme, the routing tag of a packet is made equal to its destination address. In FDR, however, the routing tag of a packet is determined by its destination address as well as source address. FDR often requires less than log₂ N stages to route a packet from its source to destination, which leads the traffic load to be reduced at the successive stages of the network. An analytical model is presented to analyze the performance of MSN under uniform traffic. Under a variety of traffic models, including uniform, hot-spot, ATM bursty, and output concentration, extensive simulations are run to examine and compare the performance of MSN with two existing similar networks. The simulation results show that MSN with FDR improves the packet loss probability substantially.