Performance Evaluation of a Combined Input- and Crosspoint-Queued Switch

This letter proposes a combined inputand crosspoint-queued (CIC) switch in which virtual output queuing (VOQ) is used at each input port. This CIC switch has a large buffer at each input port and a small buffer at each crosspoint. It does not require high-speed memory access or high-speed internal cell transmission lines. Since the performance of the CIC switch depends on the scheduling algorithms, we propose new scheduling algorithms for the CIC switch. Numerical results show that the mean cell delay time performance of the CIC switch using the proposed scheduling algorithms is better than that of an inputqueued ATM switch. In addition, the required buffer size for the CIC switch using the proposed scheduling algorithms is smaller than that for a crosspoint-queued ATM switch. key words: input-queued ATM switch, crosspoint-queued ATM