ATMSAR处理器发送数据业务的信元调度算法

The cell scheduling algorithm for ATM SAR processor transmitting data services

叙述了ATMSAR(SegmentationAndReassembly)处理器发送信元的机理 ,讨论了基于发送调度表的业务成形方式产生的信元时延抖动 (CellDelayVariation ,CDV)以及信元时延抖动容限 (CellDelayVariationTolerance ,CDVT) ,推导了CDVT的计算公式 ,设计了使CDVT最小的信元调度算法NVST(NearVirtualSdenTime) ,并分析了其性能。为了满足业务公平性进一步提出了FNVST(FairNearVirtualSendTime)信元调度算法。仿真计算结果表明FNVST可以使各业务的CDVT较为均匀。最后 ,我们讨论了FNVST算法在ATM网卡驱动程序上的应用。

This paper presents the mechanism of ATM SAR(segmentation and reassemb ly)processor transmitting data,discusses the cell delay variation(CDV)and the ce l l delay variation tolerance(CDVT)caused by the traffic shaping,which is based on transmit schedule table(TST) The formula for computing CDVT is also deduced T he cell scheduling algorithm,NVST(near virtual send time)is designed,which makes t he CDVT minimal Then the performance of NVST is analyzed In order to satisfy t he fairness of services,FNVST(fair near virtual send time)algorithm is proposed S im ulation experiments show FNVST has fair characteristics Finally,the application of FNVST algorithm in ATM NIC device driver is discussed