Performance analysis of Exhaustive Limited Service Round Robin Matching Algorithm

In this paper a performance analysis of exhaustive round-robin with limited service (ELRR) scheduling algorithm for combined input-crosspoint crossbar switches is presented. We propose using of this scheduling system for arbitration at inputs and crosspoints. If the virtual output queue (crosspoint buffer) becomes empty, the input (crosspoint) arbiter updates its pointer to the next location in a fixed order. Otherwise, the pointer remains at the current virtual output queue (crosspoint buffer). To avoid unfairness under some extremely unbalanced traffic pattern limited service matching is presented. We prove through simulations that this scheduling algorithm offers a high performance. In addition to high throughput and excellent delay performance, the switch provides timing relaxation that allows high-speed scheduling and scalability. The analyses and simulations presented in this paper enable extension of previously published results in the sense of novel performance evaluation under different traffic conditions.