DYNAMIC BUFFER ALLOCATION FOR QUALITY OF SERVICE PROVISION IN COMBINED INPUT AND CROSSPOINT BUFFERED SWITCHES

摘要

The Combined Input and Cross point Buffered (CICB) switch plays a crucial role in providing Quality of Service (QoS) in interconnection networks, which is the foundation for high-performance distributed computing. Cross point buffer space is a scarce resource in CICB switches that must be utilized efficiently. Although dynamic sharing typically improves cross point buffer utilization, it also introduces new challenges to QoS provision in CICB switches. In this paper, we address the problem of improving cross point buffer utilization while providing sufficient QoS guarantees to various traffic flows in CICB switches. We propose a dynamic buffer allocation scheme that enables sharing cross point buffer space dynamically between flows with different QoS requirements. We also develop an analytical model for evaluating the performance of this buffer allocation scheme. Our analysis shows that if buffers are shared within a certain threshold, the dynamic buffer allocation scheme improves cross point buffer utilization without sacrificing delay performance. Our analysis in this paper also quantifies the tradeoff between cross point buffer utilization and guaranteed delay performance.