带偏射补偿机制的Birkhoff-von-Neumann交换机方案及其性能分析

Birkhoff-von-Neumann（BvN）交换机具有较低的执行复杂度和较高的吞吐量，但无法在业务突发的环境下提供性能保证。为此,提出一种带偏射的BvN（D-BvN）交换机制来增强交换机性能。D-BvN交换机通过平均业务矩阵的BvN分解，为每个虚电路（VC）提供均值带宽保证，同时通过偏射来处理业务突发。其主要思想是利用处于空闲状态的VC的闲置容量处理处于溢出状态的VC的溢出业务。具体地，偏射机制利用空闲VC的闲置容量完成两件事情：一是把溢出业务偏射到其他VC，二是给偏射业务提供到达目的端口的带宽。分析和仿真结果表明，所提方法不仅可以获得接近100%的输入负载吞吐量，而且具有较低的包乱序概率和较小的业务包延时。

Design and performance analysis of deflection-compensated Birkhoff-von-Neumann switches

Although the quasi-static scheduling based on Birkhoff-von-Neumann(BvN) decomposition can achieve high throughput with low operational complexity,its performance becomes less predictable when the input traffic is bursty. In this paper,a deflection-compensated BvN(D-BvN) switch is proposed to enhance the performance.The D-BvN switch provides capacity guarantee for each virtual circuit(VC) by the BvN decomposition of average input traffic matrix, while coping with traffic burst by deflection.In particular,deflection scheme fully utilizes the spare capacity of starving VCs to deflect overflow traffic to other VCs and provide bandwidth for deflection traffic to re-access its desired VC.Analytical and simulation results show that it can achieve 100% throughput of offered load,negligible packet out-of-sequence probability and lower packet delay.