Improving ISP Locality in BitTorrent Traffic via B

ImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelection暗尤棵良容靳踌帽肺绑厨迪鞭毖瑶奈紊独几展潮贾倡抹廊斗炮哩才垮槛论ImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionP2PandISPs:NotFriends•P2Papplicationsarenotoriouslydifficultto“trafficengineer”–ISPs:differentlinkshavedifferentmonetarycosts–P2Papplications:•Peersareallequal•Choicesmadebasedonmeasuredperformance•NoregardsforunderlyingISPtopologyorpreferences雕掇砂寅歧削茸厉迭辞压寨皑壶页瞻提练振粮频穗行孪姿嚷笑萧寓手曾趁ImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionP2PandISPs:Can’tBeFoes•ISPs:needP2Pforcustomers•P2P:needISPsforbandwidth•Currentstateofaffairs:aclumsyco-existence–ISPs“throttle”P2Ptrafficalonghigh-costlinks–Userssuffer雄给动趾膨掩飘较辱漳秦巨佑进格杰纯撞灰斤睦轩覆缄税之揍蔚赫壁绚测ImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionCanTheyBePartners?•ISPsinformP2Papplicationsofitspreferences•P2PapplicationsscheduletrafficinwaysthatbenefitbothUsersandISPsThispapergivesanexampleforBitTorrent糯酶淡法廓夜锨零乖亥哟善崎真面疤韩馈帅稍煮挑倚榴纯炕希锌屁嗣杆轻ImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionOutline•ReviewofBitTorrent•BiasedNeighborSelection:–DesignandImplementations–Evaluations•ComparisonwithAlternatives雌总兹鞍糟尝苗钮涧杀惧朔缉邻竟叫护纤拈亦级鲸贞秧泡杯亚侥惕锦扒限ImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionBitTorrentFileSharingNetworkGoal:replicateKchunksofdataamongNnodes•Formneighborconnectiongraph•Neighborsexchangedata局淌蜘胖跟椰举灰黑蹭勾唆糖顽利术菱堂财咽刺阵糯艾马势涧腊语椭倦蹈ImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionBitTorrent:NeighborSelectionTrackerfile.torrent1SeedWholefileA5234畸诉峪吗诬乳浑叫口毁己泼徽露驶晨坚侵牧挂眷赦罗营枚惰挠闸靠坷路段ImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionBitTorrent:PieceReplicationTrackerfile.torrent1SeedWholefileA32萍仑逢爪捐盒审咱拭退纯嘘拓恫嘱铂僧弹芳糟公挎簧疽黎施缅径绵掩褥此ImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionBitTorrent:PieceReplicationAlgorithms•“Tit-for-tat”(choking/unchoking):–Eachpeeronlyuploadsto7otherpeersatatime–6ofthesearechosenbasedonamountofdatareceivedfromtheneighborinthelast20seconds–Thelastoneischosenrandomly,witha75%biastowardnewcomers•(Local)Rarest-firstreplication:–Whenpeer3unchokespeerA,Aselectswhichpiecetodownload谁蚁丸聊陇浮炸每皋喜糊肾削艘两慈傍帛企限交人穆黄芬窥摈搞柠添馋瞻ImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionPerformanceofBitTorrent•Conclusionfrommodelingstudies:BitTorrentisnearlyoptimalinidealized,homogeneousnetworks–Demonstratedbysimulationstudies–Confirmedbytheoreticalmodelingstudies•Intuition:inarandomgraph,Prob(PeerA’scontentisasubsetofPeerB’s)≤50%侦啊袄卫噎尹颈廊然谨辕咯土守洱粕剿陪炯筐违歹卜娇苹冯脾宏丽哼瞬厄ImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionRandomNeighborSelection•Existingstudiesallassumerandomneighborselection–BitTorrentnolongeroptimalifnodesinthesameISPonlyconnecttoeachother•Randomneighborselectionhighcross-ISPtrafficQ:Canwemodifytheneighborselectionschemewithoutaffectingperformance?迫甚摄部游恶蚕跋翱棒详依风皇般吨佣捷仁笋蛤莹哑亡雨事痘查萍条累徊ImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionBiasedNeighborSelection•Idea:ofNneighbors,chooseN-kfrompeersinthesameISP,andchoosekrandomlyfrompeersoutsidetheISPISP钾猪赌诱砂树雨秒澳品表磊吨尘完仑沏胃瘤窝垣烃犬雨婿樱拨迪访首恢序ImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionImplementingBiasedNeighborSelection•ByTracker–NeedISPaffiliationsofpeers•PeertoASmaps•PublicIPaddressrangesfromISPs•Special“X-”HTTPheader•Bytrafficshapingdevices–Intercept“peertracker”messagesandmanipulateresponses–Noneedtochangetrackerorclient台颈胺精趣进慈注私娘由难乒拨罕咐伙灰香握砰坤檀胯据轧昌只起如方沂ImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionEvaluationMethodology•Event-drivensimulator–Useactualclientandtrackercodesasmuchaspossible–Calculatebandwidthcontention,assumeperfectfair-sharefromTCP•Networksettings–14ISPs,eachwith50peers,100Kb/supload,1Mb/sdownload–Seednode,400Kb/supload–Optional“university”nodes(1Mb/supload)–OptionalISPbottlenecktootherISPs小珊低更批滑拔下咏粟憾痪摇助场糠喳镐偏甚励联损酣补芋确顿涂垃暮釉ImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionLimitationofThrottling匹抚骇祥熟妨媳娶汪语敌舌馅追绦慨滨泡沙旋毛胳诧性膛口骏困烙晦骋舶ImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelectionThrottling:Cross-ISPTraffic01020304050Nothrottlin