高速网络测试流量生成方法研究与实现2

摘要网络测试是对网络系统设施的各项性能进行检测，从而确保网络系统能顺畅的工作。要对网络系统进行测试，要用到流量生成技术，它具有较大的应用价值，测量活动的有效性和准确性都由它决定。现在已经是互联网时代，很多网络系统已经步入万兆级别，网络传输速度越来越快，对数据传输的准确性有了更高的要求，但是现有的网络测试流量生成技术还不能满足现实要求。所以，为了充分满足网络测试的现实需求，适应网络数据高速传输的需要，要加大研究投入，全面提升网络测试流量生成的速度。现有两种方法用于生成网络测试流量：其一，进行数据的回放，网络流量主要是回放前期收集到的数据信息来还原而成的；其二，使用模拟方式，先对网络信息的各种特性进行模拟，从而会产生网络流量。笔者对上面两种网络流量生成方法进行了对比，从而实现了对这两种方案的改进优化，所实现的研究成果具有较高的指导意义：1、研制的网络系统适用于各种网络设施，能实现万兆流量数据的回放。这套系统充分融合了网络主机内存大的优势，并且利用了FPGA数据传输快速准确的优点，在确保数据回放速度和准确性不变的条件下，将系统空间容量实现了大幅提升。在数据传输的时候，为了数据查询的同时进行，运用了系统内存映射机制，并在此基础上改进了网络信息传输系统。除此之外，通过运用网络系统存储大的优势，针对数据流量生成，设计了如下模式：零拷贝回放模式（利用了系统静态缓冲）、GB量级文件高速回放模式（利用了RAMdisk技术）和TB量级文件低速回放模式（应用了系统硬盘）。为了将网络数据传输的误差水平低于10E-5，设计者使用了FPGA技术，从而提升系统数据流量的准确性。2、设计的网络系统数据流模拟生成计划，运用了系统的各种部件。通过对系统中数据流进行深入分析，并充分结合系统部件的各项性能优势，所设计的系统序列是用软件实现的，所设计的方案利用了FPGA技术，从而保证生成的系统数据包是完整的。设计者还设置了系统端口用于数据的扩展，对于流的描述使用了各种系统特性。为了确保系统协议内容的兼容性，同意使用者可以对数据包的内存进行设置。除此之外，还设计了十二字节，来适应系统数据字段的改变。通过多次实验得出结论，通过使用这一方案，能确保数据传输是万兆线速的，还可以仿照不同的信息流。关键词：流量生成；软硬件协同；回放；多数据流模拟；FPGAIZhongChao(ComputerArchitecture)DirectedByXieYingkeNetworktestingisanimportantmethodtoverifythefunctionalityandmeasuretheperformanceofnetworkequipment.Asakeytechnologyinnetworkequipmenttesting,trafficgenerationdirectlydeterminestheaccuracyofthetestresults.Withtherapidexpansionofnetworkscaleandbandwidth,theexistingnetworktesttrafficgenerationtechniquesfailtomeettherequirementsintrafficgenerationrate,accuracyofrateandtrafficcontentconfiguration.Hence,theyarenoteligiblefor10Gigabitnetworktesting.Therefore,researchesabouthigh-speedtrafficgenerationmethodhavepracticalsignificanceandapplicationvalueforthedevelopmentofnetworktest.Trafficgenerationfornetworktestingcanbedividedintotwocategories:trace-driventrafficgenerationwhichgeneratestrafficbyreplayingcapturedtracefileandanalyticmodel-basedtrafficgenerationwhichreproducesnetworktrafficinreal-timebysimulatingthecharacteristicsofrealtraffic.Thesetwoprojectshavedifferentfeaturesandbothofthemhavetheirownuniqueapplicationscenes.Inthisthesis,weproposetwoimprovedtrafficgenerationsolutionsbasedonFPGAbyanalyzingthedefectsofthesetwooriginalsolutions.Theaccomplishmentswehaveachievedareasfollows.WehavedesignedatenGigabittrafficplaybacksystemcooperatinghardwarewithsoftware.ThesystemcombinesmassstoragespaceinhostPCandhighspeedandprecisioncharacteristicsofFPGAinnetworktrafficprocessing.Therefore,itallowstheplaybackfilesizetoupgradefrom64MBtotheGBorderofmagnitudewhileremaininghightrafficrateandaccuracy.Intheimplementation,memorymappingmechanismandnon-interruptpollingsynchronizationmechanismareusedtooptimizeexistingunderlyingnetworktransmissionchannel.Andahigh-speedDMAenginebasedonPCIE2.0busisdesigned.Transmissionratebetweenthehostmemoryandthenetworkcardcanreachashighas16Gbpsduetotheseoptimizations.WhiletakingadvantageofmassstoragespaceofhostPCandRAMdisktechnology,threeplaybackmodesareprovided:zero-copymodewhichplaybackpacketsfromthestaticbuffer,high-speedplaybackmodebasedonramdiskwhichsupportsfilesizeofGBorderofmagnitude,andlow-speedplaybackmodebasedondiskwhichsupportsfilesizeofTBorder.Duringthememorycopyprocess,theperformancehasincreased69%byoptimizingthecopymode.Wealsoproposedahigh-precisiontoken-basedcontrolmethodwithFPGAtokeeptheaccuracyoftrafficrateatnanosecondlevel.Wehaveimplementedamulti-flowtrafficgenerationsystemwithcollaborativehardwareandsoftware.ByanalyzingthecharacteristicsofnetworkstreamandthestrengthsofIIIResearchandRealizationofHighSpeedNetworkTestTrafficGenerationMethod高速网络测试流量生成方法研究与实现：Abstracthardwareandsoftware,anothertrafficgenerationsolutionisproposed.SoftwaregeneratestheflowcharacteristicsequenceswhileFPGAproducespacketsaccordingtotheflowcharacteristicsequence.Wedesignascalableconfigurationinterfaceofflowwhichconfiguresaflowwithastaticcharacteristicsanddynamiccharacteristics.Theinterfaceallowsuserstofreelyconfigureupto256bytespacketheadercontentforthecompatibilitywithavarietyofprotocolformats.Italsoallowsconfiguringthechangingpatternofthe12-bytefieldinordertoachievethefive-tuplechanges.WehaveimplementedthesystemusingFPGA.Thetestresultshowsthatthesystemcangeneratetrafficupto10Gigabitwire-speedrateandcancorrectlysimulatemultipledataflows.Keywords:trafficgeneration,hardware-softwarecooperation,playback,multi-flowsimulating,FPGAIV目录摘要...................................................................................................................................................I目录..................................................................................................................................................V图目录............................................................................................................................................VII表目录.............................................................................................................................................XI第一章引言...............................................................................................................................11.1研究背景和意义..........................................................