Faculty of Electrical Engineering, Mathematics and Computer Science Network Architectures and Services Analyzing P2PTV Traffic Via Measurement C Jiang (1379844) Committee members: Supervisor: Prof.dr.ir. Piet Van Mieghem Mentor: Siyu Tang Dr.ir. Fernando Kuipers Member: Prof.dr.ir. Piet Van Mieghem Dr.ir. Fernando Kuipers Dr. Christian. Doerr Dr.ir. Anthony Lo 10 th July, 2009 M.Sc. Thesis No: PVM 2009 – 056 Copyright ©2009 by C Jiang All rights reserved. No part of the material protected by this copyright may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording or by any information storage and retrieval system, without the permission from the author and Delft University of Technology. 2 Analyzing P2PTV Traffic Via Measurement THESIS submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE In EMBEDDED SYSTEMS By Chengcheng Jiang born in Hangzhou, China Network Architectures and Services Group Faculty of Electrical Engineering, Mathematics and Computer Science Delft University of Technology 3 4 Preface This research work was carried out at the Faculty of Electrical Engineering Mathematics and Computer Sciences with the Network Architectures and Services Group of Delft University of Technology. It was from September 2008 to July 2009. Many people contributed to this work. First I would like to express my sincere appreciation to Siyu Tang, who not only guided my thesis but also encouraged me through the whole process. And I also appreciate the supervising and support from assistant professor Fernando A. Kuipers. My deepest gratitude goes to my supervisor Prof. P. F. A. Van Mieghem for his precise attitude on science. I gratefully acknowledge my friends at the Department of Embedded Systems and Telecommunications for making such a productive work environment. Last but not least, I would like to thank my family for their constant love and support. 5 6 Abstract In recent year, the P2P television (P2PTV) becomes the most popular application for Internet users, due to the rapid development of peer-to-peer (P2P) technology. The efficiency and quality is the most important issue for P2PTV applications. Therefore, understanding and analyzing the performance of different P2P networks is one of the most important aspects in the research field. In this thesis, we evaluate the traffic pattern of a mesh based P2PTV network, i.e. SopCast, via an experimental study. We also try to dissect the operational mechanisms in the SopCast, e.g. criteria of selecting peers, in which way the network copes with node churn, etc. Our experiments are conducted on PlanetLab. A source provider (SP) and a set of PlanetLab nodes are controlled to form a private P2PTV network which makes it possible to collect the traffic of a complete P2PTV network We designed two scenarios during the experiment. The first scenario is a relative stable network, and the second one focuses on the overlay dynamics. We found that the super-peers selection algorithm of SopCast is based on the registration time with the SP, and the SopCast system copes well with the dynamics of super-peers. The results help us to understand the behavior and the operational mechanism of SopCast. The analysis also helps us to understand similar P2PTV networks. ASSIGNMENT : Master of Science Thesis INSTRUCTORS : Siyu Tang Dr. F. A. Kuipers SUPERVISOR : Prof. Dr. Ir. Van Mieghem DATE : July 10th, 2009 7 8 Table of Content Abstract.......................................................................................................... 7 List of Figures.............................................................................................. 11 1 Introduction............................................................................................... 13 1.1 Background....................................................................................................................... 15 1.1.1 P2PTV ................................................................................................................... 15 1.1.2 BitTorrent............................................................................................................... 17 1.1.3 Available P2PTV Applications .............................................................................. 21 1.2 Motivation and Objective ................................................................................................. 22 1.3 Thesis outline.................................................................................................................... 24 2 Literature Survey...................................................................................... 25 2.1 P2P Network Measurement and Development................................................................. 25 2.2 Peer Selection Policy........................................................................................................ 26 3 Experimental setting on PlanetLab......................................................... 29 3.1 The SopCast Streaming System........................................................................................ 29 3.2 Overview of PlanetLab..................................................................................................... 32 3.3 Experiment Set-up ............................................................................................................ 33 4 The Video Delivery Pattern and Peer Selection Criterion in the SopCast Network ..................................................................................... 37 4.1 Scenario Description......................................................................................................... 37 4.2 Stability of the Paths in the Underlying Network............................................................. 37 4.3 The SopCast Traffic Distribution...................................................................................... 38 4.4 The Super-peer Selection Algorithm in SopCast .............................................................. 41 4.4.1 The impact of the delay and hopcount................................................................... 41 4.4.2 The Impact of the Registration Process ................................................................. 43 4.4.3 The Impact of Bandwidth ...................................................................................... 45 4.5 The Degree Distribution of the SopCast Three Layer Network........................................ 46 5 The Impact of Peer Dynamics in the SopCast System.......................... 51 5.1 Scenario Description......................................................................................................... 51 5.2 The Impact of Adding Peers to the SopCast Network ...................................................... 52 5.3 The Impact of Super-peers’ Departure.............................................................................. 54 5.4 Discussion on the SopCast protocol ................................................................................. 56 9 5.4.1 Communication between the normal peers and the SP.......................................... 56 5.4.2 Number of super-peers in larger-scale SopCast network....................................... 57 5.4.3 The 20-bytes Packets ............................................................................................. 58 6 Conclusion and Future Work................................................................... 61 6.1 Conclusion........................................................................................................................ 61 6.2 Future Work...................................................................................................................... 62 Reference ..................................................................................................... 65 Abbreviation................................................................................................. 69 10 List of Figures Figure 1.1: The P2P network and client-server network. ....................................................... 13 Figure 1.2: Single Tree Based Network.................................................................................. 16 Figure 1.3: Mesh Based Network. .......................................................................................... 17 Figure 1.4: Comparison of different P2P networks. ............................................................... 18 Figure 1.5: Working of the BitTorrent network. .................................................................... 19 Figure 1.6: The two layer structure of P2P network............................................................... 23 Figure 3.1: The SopCast user interface................................................................................... 30 Figure 3.2: The SopCast broadcast interfere. ......................................................................... 31 Figure 3.3: The GUI of PlMan (windows version)................................................................. 34 Figure 4.1: The download throughput and upload throughput for each peer.......................... 39 Figure 4.2: The three layer structure of SopCast network...................................................... 40 Figure 4.3: The detail of super-peers’ traffic distribution....................................................... 41 Figure 4.4: Hopcount distribution from SP to each peer and from SP to super-peers...........