动态ECN阈值测试方法及qp公平性的重要性.pdf

1、Dynamic ECN testing methodology Dynamic ECN testing methodology&Importance of QP&Importance of QP-fairnessfairnessKEYSIGHTNETWORKINGDynamic ECN testing methodology&Importance of QP-fairnessEric YUSolution Architect/KeysightAvik BhattacharyaSr Product Manager/KeysightOutline54321How ECN threshold/DCQ

2、CN worksHow Dynamic ECN threshold helpsTesting methodology for ECN thresholdWhat is Queue Pair fairnessFairness importanceECN threshold and DCQCN https:/ ECN entryNIC responsivenessresponsivenessSmall data size Small data size early stop hereHigh ECN entryHigh latencyBig data sizeBig data sizedeep d

3、epth for long timeEasy deploymentAdapt to network dynamicsDynamic ECN thresholdLow ECN entryNIC responsivenessPFCRxECN-CERxMaxLatency(ns)AvgLatency(ns)MinLatency(ns)High Entry1046514181336412 233647 12302Low Entry479986872332670 179785 122800100200300400 x1000Data size 8GB High EntryLow EntryHigh EC

4、N entryHigh latencyResponsive ConservativeAll test under 400G speedAvailable bandwidthAll-To-All2311.ECN marking accuracy2.NIC responsiveness emulation3.PFC generation for network dynamics4.Other dynamics e.g.in-cast,rate of ECN-CETesting Methodology for ECN Threshold TxRxPFCPFCPFCRecord ECN-CE coun

5、tersTxRxRocev2 98%PFCDCQCN96%bandwidthPFC HeadroomTimer T-RTimer T-CECN-CE counters goes downTxRxRocev2 98%PFCDCQCN96%bandwidth50%bandwidthPFC/Ave latency goes downCollective benchmarkTesting Methodology for ECN Threshold In-castBusbw(GB/s)Dynamic ECN23.55Static ECN1.49051015202516 Ranks All-To-All

6、Data size 128MB Dynamic ECNStatic ECNCollective benchmarkQueue Pair FairnessPFC RxECN-CE RxDynamic ECN14691837Static ECN13782400500100015002000PFC/ECN-CEDynamic ECNStatic ECNCollective benchmarkQueue Pair FairnessNIC ResponsivenessTransceiv