Modeling and Performance Evaluation of ATM Switches

In this work, we present a Colored Petri Net (CPN) model used for prototyping and modeling a complex switching scheme for ATM switches based on the combined I/O buffering technique. The new scheme is evaluated here within an overall setting that includes the traffic regulations enforced by the leaky bucket algorithm. It is based on splitting the traffic coming into input lines into two priority queues (High and Low) where traffic destined to busy ports is directed to the low priority queue. This scheme was compared against pure combined I/O buffering and simulation results showed that the new scheme pays back in decreasing transmission delay only when the traffic increases beyond a certain level. In addition the sensitivity analysis of the bucket size showed also that this latter affects the performance of the system only at high loads. Keyword: Combined I/O Buffering, Priority Queues, ATM Switches, Leaky Bucket regulator