Analysis of a Shared-Private Buffer Management Scheme for Shared Memory Switches

摘要

Burst traffic is a common traffic pattern in modern communication networks, and this traffic is the main cause of the unfairness problem in shared memory switch. In this paper, a shared-private buffer management (SPBM) scheme is proposed, which can efficiently utilize the switch buffer and reduce overall packet loss rate under burst traffic. The key idea of SPBM is to partition the total memory space into shared area and private area. Each output port has a private memory area that cannot be used by other ports. The shared area is completely shared among all output ports. A theoretical queuing model of the proposed scheme is formulated and closed-form formula for the overall packet loss rate is derived. By analyzing the numerical results, the optimal partition of the switch buffer is obtained. Besides, simulation result shows that the proposed scheme can reduce the overall packet loss rate by about 20% on average compared with existing buffer management schemes.