不對稱網(wǎng)絡(luò)的TCP擁塞控制算法研究.pdf

1、南京郵電大學(xué)碩士學(xué)位論文不對稱網(wǎng)絡(luò)的TCP擁塞控制算法研究姓名：王會靈申請學(xué)位級別：碩士專業(yè)：計(jì)算機(jī)應(yīng)用技術(shù)指導(dǎo)教師：桂志波20060401南京||l|5IU大學(xué)傾十研究生學(xué)位論文摘要TCPCongestionControlAlgorithmResearchOverAsymmetricNetworksABSTRACTAsinthecurrentnetworks，95％oftotalbytesnseTCPTransmission，andi

2、tisveryimportantthataTCPend—to—endcongestioncontrolisusedforInternet’srobustnessandstabilityThispapermainlydiscussedtheresearchonandimprovementofTCPCongestionControlAlgorithmThispaperfirstlyanalyzestheoccurrenceofcongest

3、iollinnetwork，andpresentsthenecessarityofcongestioncontrolandtakescategorizationofcongestioncontrol；thenintroducestwocurrentcongestioncontrolalgorithms，TCPRenoandTCPVegas，whicharemainlydesignedfortraditionalnetworkandwel

4、lresolvethecasethatcongestionwouldoccurontheforwardpathHoweverSeveralemergingbandwidth—asymmetricnetworksandpacketradiosubnetworksexhibittheirasymmetriccharacteristicTCPperformanceoftendegradessignificantlybecausetheeffe

5、ctofasymmetriccharacteristics，forexample，congestionalongthebackwardpathaffectsuchperformanceasthroughput，packetlossratioalongtheforwardpathRenoisastandardTCPcongestioncontrolalgorithm，whichconsistsoffourmechanisms，ie，Slo

6、wStart，CongestionAvoidance，F(xiàn)astRetransmitandFastRecoveryVegasisintroducedasanalternativetoTCPRenoIncontrasttoReno，whichusespacketlossasthemeasureofcongestion，Vegasusesdelayasthemeasureofcongestienandanticipatestheonsetof

7、congestionbymonitoringthedifferencebetweentheexpectedrateandtheactuallymeasuredrateInordertoaddressbackwardcongestionoverasymmetricnetworks，somesolutions，eg，TCPHeaderCompression，TCPFiltering，ACKcongestioncontrol，ACKFirst

8、SchedulingareproposedTheseschemeshaveimprovedtheperformanceofTCPRenoforasymmetricnetworks，buttheyarenoteffectiveforhandlingtheVegas’asymmetryproblemsBasedonanalyzingcharacteristicsofVegas’congestionavoidance，animprovedal