ImprovingISPLocalityinBitTorrentTrafficviaBiasedNeighborSelection.ppt
Improving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,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Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,P2P and ISPs:Not Friends,P2P applications are notoriously difficult to“traffic engineer”ISPs:different links have different monetary costsP2P applications:Peers are all equalChoices made based on measured performanceNo regards for underlying ISP topology or preferences,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Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,P2P and ISPs:Cant Be Foes,ISPs:need P2P for customersP2P:need ISPs for bandwidthCurrent state of affairs:a clumsy co-existenceISPs“throttle”P2P traffic along high-cost linksUsers suffer,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Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,Can They Be Partners?,ISPs inform P2P applications of its preferencesP2P applications schedule traffic in ways that benefit both Users and ISPs This paper gives an example for BitTorrent,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Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,Outline,Review of BitTorrent Biased Neighbor Selection:Design and ImplementationsEvaluationsComparison with Alternatives,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Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,BitTorrent File Sharing Network,Goal:replicate K chunks of data among N nodesForm neighbor connection graphNeighbors exchange data,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Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,BitTorrent:Neighbor Selection,Trackerfile.torrent,1,Seed,Whole file,A,5,2,3,4,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Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,BitTorrent:Piece Replication,Trackerfile.torrent,1,Seed,Whole file,A,3,2,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Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,BitTorrent:Piece Replication Algorithms,“Tit-for-tat”(choking/unchoking):Each peer only uploads to 7 other peers at a time6 of these are chosen based on amount of data received from the neighbor in the last 20 secondsThe last one is chosen randomly,with a 75%bias toward new comers(Local)Rarest-first replication:When peer 3 unchokes peer A,A selects which piece to download,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Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,Performance of BitTorrent,Conclusion from modeling studies:BitTorrent is nearly optimal in idealized,homogeneous networksDemonstrated by simulation studiesConfirmed by theoretical modeling studiesIntuition:in a random graph,Prob(Peer As content is a subset of Peer Bs)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Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,Random Neighbor Selection,Existing studies all assume random neighbor selectionBitTorrent no longer optimal if nodes in the same ISP only connect to each otherRandom neighbor selection high cross-ISP trafficQ:Can we modify the neighbor selection scheme without affecting performance?,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Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,Biased Neighbor Selection,Idea:of N neighbors,choose N-k from peers in the same ISP,and choose k randomly from peers outside the ISP,ISP,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Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,Implementing Biased Neighbor Selection,By TrackerNeed ISP affiliations of peersPeer to AS mapsPublic IP address ranges from ISPsSpecial“X-”HTTP headerBy traffic shaping devicesIntercept“peer tracker”messages and manipulate responsesNo need to change tracker or client,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Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,Evaluation Methodology,Event-driven simulatorUse actual client and tracker codes as much as possibleCalculate bandwidth contention,assume perfect fair-share from TCPNetwork settings14 ISPs,each with 50 peers,100Kb/s upload,1Mb/s downloadSeed node,400Kb/s uploadOptional“university”nodes(1Mb/s upload)Optional ISP bottleneck to other ISPs,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Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,Limitation of Throttling,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Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,Throttling:Cross-ISP Traffic,Redundancy:Average#of times a data chunk enters the ISP,昆惑牲驹橱劲伙鳃仙啪搓巍锰公辕愈饱俊霹枣帮盘似呜钥肄卒避患坎凸渗Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,Biased Neighbor Selection:Download Times,扒追鳞礼澎换航绩溯坟环旨拌谈佩卒纲梁姥导轧挡络奎志锚播申箩灌影检Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,Biased Neighbor Selection:Cross-ISP Traffic,杏侈谣时悯式撮压跨坏辊税洲绣惶犁士盔输戴示钳纠枢引划营砌痒舜锅婴Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,Importance of Rarest-First Replication,Random piece replication performs badlyIncreases download time by 84%-150%Increase traffic redundancy from 3 to 14Biased neighbors+Rarest-First More uniform progress of peers,镊呻栗沁陕砌挥宪篆壹陡抑翁宠滨虽乐仕梭畸寇囊呸冉触辅操腋拨兵酗儒Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,Biased Neighbor Selection:Single-ISP Deployment,署面永斋姻右屠暴译升僳暑饲寇蚜吨瓣裔扼狸传府汤匿柄尝奋堡粪蓖战阂Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,Presence of External High-Bandwidth Peers,Biased neighbor selection alone:Average download time same as regular BitTorrentCross-ISP traffic increases as#of“university”peers increaseResult of tit-for-tatBiased neighbor selection+Throttling:Download time only increases by 12%Most neighbors do not cross the bottleneckTraffic redundancy(i.e.cross-ISP traffic)same as the scenario without“university”peers,卫柠铝拯攫抑姥绰脏若寒灸惋孟漾秧厌棵杏亨蔼陕瓮蛇漆乒伺黑之观疑等Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,Comparison with Alternatives,Gateway peer:only one peer connects to the peers outside the ISPGateway peer must have high bandwidthIt is the“seed”for this ISPEnds up benefiting peers in other ISPsCaching:Can be combined with biased neighbor selectionBiased neighbor selection reduces the bandwidth needed from the cache by an order of magnitude,唉弯电琶励爷蘑雀革寨孔此篱酷架沿值姐枉澎荡验墨代琵愧谬比栈幻抉碴Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,Summary,By choosing neighbors well,BitTorrent can achieve high peer performance without increasing ISP costBiased neighbor selection:choose initial set of neighbors wellCan be combined with throttling and caching P2P and ISPs can collaborate!,澈芳述幕籍氨土站适毒疙袋而嗡砂录郸史灶慧庐塘最速烬迢嚏苹兜存锭十Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,Related Work,Many modeling studies of BitTorrentSimulation studiesMeasurements of real torrents,算贬殊匡兑学磋谆寒摧劣桥门层陶缕谜屎妖辙求伪有非割谩帧睡摧富柔蒂Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,Future Work,Implementation of tracker-side changes and experimentsTheoretical modeling of biased neighbor selectionDynamic biased neighbor selection for“global congestion avoidance”,菜窃村鹿杆仓先谬高皿蔡廖倚恫限滨桶此攒幌镜涎脂锯兜产腹刨蔼粟腔谜Improving ISP Locality in BitTorrent Traffic via Biased Neighbor SelectionImproving ISP Locality in BitTorrent Traffic via Biased Neighbor Selection,
