Bandwidth assignment with QoS guarantee in scalable ATM switches

In asynchronous transfer mode (ATM) switching systems, switch fabrics must be able to provide not only internally conflict-free paths for cells, but also quality of service (QoS) guarantee for calls. Most research concerning QoS guarantee focuses on the service disciplines of output-buffered switches. However, the scalability of output-buffered switches is rather low because of high implementation complexity. Previously, a new switching implementation called the cross-path switch has been proposed to achieve high throughput and low complexity. This paper addresses fundamental issues related to service disciplines in such a switch that are needed to achieve optimal performance. In particular we propose an algorithm to implement a multi-level stop-and-go queueing strategy that integrates the routing and scheduling functions. We show that our algorithm provides a tight delay bound and ensures that desirable traffic characteristics are preserved when cell traverse across the switch