University of Nevada, Reno Virtual Direction Multicast for Overlay Networks A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Computer Science and Engineering by Suat Mercan Dr. Murat Yuksel Dissertation Advisor August, 2011 THE GRADUATE SCHOOL We recommend that the dissertation prepared under our supervision by SUAT MERCAN entitled Virtual Directional Multicast for Overlay Networks be accepted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Murat Yuksel, Ph.D., Advisor Mehmet H. Gunes, Ph.D., Committee Member Monica Nicolescu, Ph.D., Committee Member Sergiu Dascalu, Ph.D., Committee Member Gokhan Pekcan, Ph.D., Graduate School Representative Marsha H. Read, Ph. D., Associate Dean, Graduate School August, 2011 i Virtual Direction Multicast for Overlay Networks Suat Mercan University of Nevada, Reno, 2011 Advisor: Dr. Murat Yuksel Abstract Recently emerged Internet applications such as Internet TV, tele-conferencing and online education requires group communication, also known as “multicast”. Many researchers have put their research focus on achieving a robust and efficient way of sending traffic via multicast. Network layer multicast attracted the attention for years; but, because of deployment issues of network layer multicast, it has not been deployed widely. Overlay multicast (i.e., application layer multicast) is a promising alternative solution in which multicast functionalities are implemented in the appli- cation layer. We propose Virtual Direction Multicast (VDM) which aims to minimize net- work usage and increase user-perceived quality for video multicast applications on peer-to-peer overlay networks. VDM locates the end hosts relative to each other based on a virtualized orientation scheme and it builds its multicast tree by con- necting the nodes which are estimated to be in the same virtual direction that are determined by virtual distances among the nodes. By using the concept of direction- ii ality, we target to consume minimal resources of the underlying network and increase user satisfaction. Another aim of using virtual distance is to adapt overlay multicast tree to different performance targets desired by applications. Sensitivity of applica- tions differs against various network performance metrics, e.g., delay is crucial for video conferencing which includes interactivity while it is not so significant for video streaming that is highly sensitive to loss. Calculating virtual distances based on given application-specific preferences is a key capability of VDM and it enables the system to accommodate specific performance targets while providing a generalized framework to establish the overlay trees. We perform extensive evaluation of VDM and compare it against the Host Multicast Tree Protocol (HMTP) that connects nearby nodes to construct the multicast tree. Our simulation results and Planetlab implementation show that our proposed technique VDM consistently outperforms HMTP under dif- ferent churn rates for some key measures such as network usage and user-perceived quality. iii To my Family iv Acknowledgments First, I like to thank my advisor Dr. Murat Yuksel for his invaluable teaching, mo- tivation and patience through my graduate study. His guidance helped me in my research and writing my dissertation. Besides my advisor, I want to thank other committee members: Dr. Mehmet H. Gunes, Dr. Monica Nicolescu, Dr. Sergiu Dascalu and Dr. Gokhan Pekcan for their time and comments. I also like to thank all my teachers from 1st grade up to now for their contributions to my knowledge. I really appreciate understanding of my wife and mother that I could not spend much time for them. My special thanks go to some people that they supported financially in my hard times and never ask for that until I pay back. I should mention my lab mates in Computer Networking Lab. Our lab has very friendly atmosphere with their warm and lovely behaviors. Insightful discussions have contributed to our understanding. Suat Mercan University of Nevada, Reno August 2011 v Contents Abstract i Acknowledgments iv List of Figures viii Chapter 1 Introduction 1 1.1 Contributions ............................... 5 1.2 OrganizationofDissertation . 6 Chapter 2 Related Work 8 2.1 TypesofDataDelivery.......................... 9 2.1.1 Unicast .............................. 9 2.1.2 Broadcast ............................. 10 2.1.3 Multicast ............................. 10 2.2 ContentDeliveryNetworks(CDNs) . 11 2.3 NetworkLayerMulticast . 12 2.4 ApplicationLayerMulticast . 14 2.4.1 OverlayNetwork ......................... 14 2.4.2 MulticastinOverlay . 15 vi 2.4.3 Application Layer Multicast Considerations . .. 16 2.4.4 Previous Studies on Peer-to-Peer Multicast . ... 18 2.4.5 AvailableP2PTVApplications . 19 2.4.6 BananaTreeProtocol(BTP) . 20 2.4.7 HostMulticastTreeProtocol(HMTP) . 21 2.4.8 SplitStream ............................ 22 2.4.9 NICE ............................... 23 2.4.10 Narada............................... 24 2.4.11 Topology-AwareNodeSelection . 25 2.4.12 ContentAddressableNetwork(CAN) . 25 Chapter3 VirtualDirectionMulticast 27 3.1 ProtocolDescription ........................... 28 3.1.1 KeyDesignConsiderations. 28 3.1.2 VirtualDirectionalityonaLine . 30 3.2 JoinProcess................................ 32 3.2.1 JoinExamples........................... 34 3.2.2 MoreComplexJoinExamples . 37 3.2.3 ComplexityAnalysis . 41 3.3 Reconnection ............................... 42 3.4 Refinement ................................ 44 3.5 VDMversusHMTP ........................... 45 3.6 SimulationExperiments . 47 3.6.1 SimulationBasics. 48 3.6.2 SimulationSetup ......................... 49 vii 3.6.3 PerformanceMetrics . 50 3.6.4 SimulationResults . 52 Chapter 4 Generalizing Virtual Directions for Various Metrics 61 4.1 Generalization............................... 61 4.2 VDM-DversusVDM-L.......................... 65 Chapter5 PlanetLabImplementation 69 5.1 PlanetLabEnvironment . 69 5.2 VirtualDirectionMulticastonPlanetLab. ... 70 5.2.1 NodeSelection .......................... 70 5.2.2 Implementation .......................... 71 5.3 PerformanceMetrics ........................... 75 5.4 Results................................... 77 5.4.1 SampleTree............................ 77 5.4.2 VDMversusHMTP ....................... 79 5.4.3 PerformanceversusNumberofNodes . 84 5.4.4 PerformanceversusNodeDegree . 88 5.4.5 RefinementComponent. 92 5.4.6 ComparisonwithMinimumSpanningTree . 94 Chapter6 SummaryandFutureWork 96 6.1 Summary ................................. 96 6.2 FutureWork................................ 98 Bibliography 99 viii List of Figures 2.1 Unicast .................................. 9 2.2 Broadcast ................................. 10 2.3 Multicast ................................. 11 2.4 NetworkLayerMulticast . 14 2.5 OverlayNetwork ............................. 15 2.6 ApplicationLayerMulticast . 15 2.7 SiblingswitchinBTP .......................... 21 2.8 JoinProcedureforHMTP ........................ 22 2.9 SplitStream ................................ 23 2.10NICE ................................... 24 2.11Narada................................... 25 2.12JoininCAN................................ 26 3.1 DirectionalityConcept.. 30 3.2 CaseI. ................................... 31 3.3 CaseII.................................... 31 3.4 CaseIII. .................................. 31 3.5 AnotherillustrationforCaseIII. .. 32 ix 3.6 Joinprocedure. .............................. 33 3.7 A sample overlay tree with source and some children. ..... 35 3.8 AjoinexampleillustratingCaseI. .. 35 3.9 A join example illustrating CaseIII and CaseI sequentially. ...... 36 3.10 A join example illustrating CaseIII and CaseII sequentially.. 36 3.11 A join example illustrating CaseIII and CaseII. ...... 37 3.12 Differentjoinscenarios.. 38 3.13 CaseII is existing with two different children in the sameiteration. 38 3.14 CaseIII is existing with two different children in the same iteration. 39 3.15 CaseII is existing with one child and CaseIII is with another child in thesameiteration. ............................ 40 3.16 C3 is not able to find C2 directionality divergence. ....... 40 3.17 N needs to contact grandchildren of P to find C2. ... 41 3.18 ReconnectionProcedure . 43 3.19 Orphan nodes starts reconnection at grandparent. ....... 44 3.20 SourceRefinement. ............................ 44 3.21 Scenario I showing the difference between VDM and HMTP. .. 46 3.22 ScenarioII showing the difference between VDM and HMTP. ... 46 3.23 Stressvaluesoflinksareshown . 50 3.24 Stretchvaluesoflinksareshown. .. 51 3.25Stressvs.Churn. ............................. 53 3.26Stretchvs.Churn. ............................ 54 3.27Lossratevs.Churn. ........................... 54 3.28 Overheadvs.Churn. ........................... 55 3.29 Stressvs.NumberofNodes. 56 x 3.30 Stretchvs.NumberofNodes. 56 3.31 Lossratevs.NumberofNodes. 57 3.32 Overheadvs.NumberofNodes. 57 3.33 Stressvs.NodeDegree. 58 3.34 Stretchvs.NodeDegree.. 59 3.35 Lossratevs.NodeDegree.. 59 3.36 Overheadvs.NodeDegree. 60 4.1 Delay and Loss rate values of a triangle among San Francisco, Boston andDallas. ................................ 62 4.2 Delay and Loss rate values of a triangle among Chicago, Tokyo and Johannesburg................................ 63 4.3 Asampletopology. ............................ 63 4.4 Relativevirtualdistances. 64 4.5 Differentlyformedoverlaytrees. .. 64 4.6 Stressvs.Time............................... 66 4.7 Stretchvs.Time. ............................