A large ATM switch based on memory switches and optical star couplers

The authors propose a large asynchronous transfer mode (ATM) switch architecture based on memory switches of the type being developed by several research groups and on optical star couplers. Fast contention resolution makes it possible to combine a number of these modules, memory switches, and optical stars in order to attain a capacity of 2.5 Tb/s. This switch architecture has a relatively small failure group size of 128 STS-3 lines out of a total of 16384. The scaling of the switch to smaller capacities is discussed, showing how tradeoffs in the various parameters can be used to overcome particular technological limitations. Fault tolerance and recovery schemes are presented, showing that with minimal increase to the switch complexity and cost, a very reasonable fault recovery scheme is available for almost every sort of failure