一种新的逐跳显式拥塞控制机制及性能分析.docx

一种新的逐跳显式拥塞控制机制及性能分析
摘要
本文提出一种新的逐跳显式拥塞控制机制，并对其性能进行了分析。该机制使用了基于单一图像和矩形比较法的拥塞控制算法，并通过增加逐跳显式拥塞控制机制来提高网络的性能。利用网络仿真软件NS2，我们进行了一系列实验，证明了这种逐跳显式拥塞控制机制在提高网络端到端性能，减少网络拥塞以及降低网络延迟等方面具有优越性。
关键词：逐跳显式拥塞控制，拥塞控制算法，网络性能分析
Introduction
Asthescaleoftheinternetcontinuestoexpand,theproblemofcongestioncontrolisbecomingmoreandmoreprominent.Congestioninthenetworkcausesnetworkdelaysandpacketloss,whichseriouslyaffectsthequalityofthenetworkservice.Atpresent,mostresearchoncongestioncontrolisbasedonend-to-endcongestioncontrol,butend-to-endcongestioncontrolalonecannotfullysolvetheproblemofnetworkcongestion.Inthispaper,weproposeanewhop-by-hopexplicitcongestioncontrolmechanismtoimprovenetworkperformance.
RelatedWork
Therehavebeenmanycongestioncontrolmechanismsproposedinrecentyears,includingend-to-endcongestioncontrolmechanismsandhop-by-hopcongestioncontrolmechanisms.End-to-endcongestioncontrolmechanismsaregenerallyclassifiedintotwocategories:window-basedcongestioncontrolandrate-basedcongestioncontrol.Examplesofwindow-basedmechanismsincludeTCPRenoandTCPVegas,andexamplesofrate-basedmechanismsincludeTCPWestwoodandTCPHybla.Thesemechanismsrelyonend-to-endfeedbacktodeterminethedegreeofnetworkcongestion,buttheycannothandlecongestionatthenetworklayer.Hop-by-hopcongestioncontrolmechanisms,ontheotherhand,canhandlecongestionatthenetworklayerandpromotetheefficienttransferofdataacrossthenetwork.Examplesofhop-by-hopmechanismsincludeRandomEarlyDetection(RED)andExplicitCongestionNotification(ECN).
ProposedMechanism
Ourproposedmechanismusesacongestioncontrolalgorithmbasedonsingle-imageandrectanglecomparison,combinedwithhop-by-hopexplicitcongestioncontroltoimprovenetworkperformance.Thealgorithmisimplementedintwosteps:
-Thecongestioncontrolalgorithmisusedtodeterminethedegreeofnetworkcongestion.Thisalgorithmusesasingleimageandarectanglecomparisonmethodtodeterminewhetherthenetworkiscongested,andadjuststhesendingrateaccordingly.
-Thehop-by-hopexplicitcongestioncontrolmechanismisusedtocontrolnetworkcongestion.Thismechanis