Sharing Network Measurements on Peer-to-Peer Networks Bo FAN A thesis submitted in fulfilment of the requirements for the degree of Master of Philosophy (Research) in Electrical Engineering and Telecommunications School of Electrical Engineering and Telecommunications The University of New South Wales February, 2007 PLEASE TYPE THE UNIVERSITY OF NEW SOUTH WALES Thesis/Dissertation Sheet Surname or Family name: Fan First name: Bo Other name/s: Abbreviation for degree as given in the University calendar: MPhil School: School of Electrical Engineering and Faculty: Engineering Telecommunications Title: Miss Abstract 350 words maximum: (PLEASE TYPE) With the extremely rapid development of the Internet in recent years, emerging peer-to-peer network overlays are meeting the requirements of a more sophisticated communications environment, providing a useful substrate for applications such as scalable file sharing, data storage, large-scale multicast, web-cache, and publish-subscribe services. Due to its design flexibility, peer-to-peer networks can offer features including self-organization, fault-tolerance, scalability, load-balancing, locality and anonymity. As the Internet grows, there is an urgent requirement to understand real-time network performance degradation. Measurement tools currently used are ping, traceroute and variations of these. SNMP (Simple Network Management Protocol) is also used by network administrators to monitor local networks. However, ping and traceroute can only be used temporarily, SNMP can only be deployed at certain points in networks and these tools are incapable of sharing network measurements among end-users. Due to the distributed nature of networking performance data, peer-to-peer overlay networks present an attractive platform to distribute this information among Internet users. This thesis aims at investigating the desirable locality property of peer-to-peer overlays to create an application to share Internet measurement performance. When measurement data are distributed amongst users, it needs to be localized in the network allowing users to retrieve it when external Internet links fail. Thus, network locality and robustness are the most desirable properties. Although some unstructured overlays also integrate locality in design, they fail to reach rarely located data items. Consequently, structured overlays are chosen because they can locate a rare data item deterministically and they can perform well during network failures. In structured peer-to-peer overlays, Tapestry, Pastry and Chord with proximity neighbour selection, were studied due to their explicit notion of locality. To differentiate the level of locality and resiliency in these protocols, P2Psim simulations were performed. The results show that Tapestry is the more suitable peer-to-peer substrate to build such an application due to its superior localizing data performance. Furthermore, due to the routing similarity between Tapestry and Pastry, an implementation that shares network measurement information was developed on freepastry, verifying the application feasibility. This project also contributes to the extension of P2Psim to integrate with GT-ITM and link failures. Declaration relating to disposition of project thesis/dissertation I hereby grant to the University of New South Wales or its agents the right to archive and to make available my thesis or dissertation in whole or in part in the University libraries in all forms of media, now or here after known, subject to the provisions of the Copyright Act 1968. I retain all property rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertation. 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FOR OFFICE USE ONLY Date of completion of requirements for Award: THIS SHEET IS TO BE GLUED TO THE INSIDE FRONT COVER OF THE THESIS ORIGINALITY STATEMENT ‘I hereby declare that this submission is my own work and to the best of my knowledge it contains no materials previously published or written by another person, or substantial proportions of material which have been accepted for the award of any other degree or diploma at UNSW or any other educational institution, except where due acknowledgement is made in the thesis. Any contribution made to the research by others, with whom I have worked at UNSW or elsewhere, is explicitly acknowledged in the thesis. I also declare that the intellectual content of this thesis is the product of my own work, except to the extent that assistance from others in the project's design and conception or in style, presentation and linguistic expression is acknowledged.’ Signed …………………………………………….............. Date …………………………………………….............. i Acknowledgement Most of all I would like to thank my supervisor Dr. Tim Moors for giving me this opportunity to do research with him and for his encouragement, patience and guidance through the whole research journey. His insightful opinion has always led me to make right decisions in the critical stage of my research, keeping me on the right track. I would like to thank Tim Hesketh, Head of Electrical Engineering School to introduce this Master of Philosophy programme to me. I also wish to give my thanks to Phillip Allen from Electrical Engineering School for his help to build the experimental network and all the convenience of equipment access he provided. I would also like to express my gratitude to my research colleagues in 343E, Tim Hu for his valuable hints and Sameer Qazi to proofread my thesis. Especially, I would like to thank my parents for their emotional and long-term financial support. ii Abstract With the extremely rapid development of the Internet in recent years, emerging peer-to-peer network overlays are meeting the requirements of a more sophisticated communications environment, providing a useful substrate for applications such as scalable file sharing, multicasting and publish-subscribe services. Peer-to-peer networks can offer desirable features such as self-organization, fault-tolerance, scalability, load-balancing, locality (proximity) and anonymity. As the Internet grows, there is an urgent requirement to understand real-time network performance degradation. While measurements can be made using tools such as ping and traceroute, and network administrators can monitor local networks using SNMP (Simple Network Management Protocol), there are currently no tools for sharing measurements among end-users. Due to the distributed nature of networking performance data, peer-to-peer overlay networks present an attractive platform to distribute this information among Internet users. This thesis investigates the desirable locality property of peer-to-peer overlays to determine their suitability for creating an application to share Internet measurement performance. When measurement data are distributed amongst users, users need to be able to retrieve localise copies to improve the chance of access when external Internet links fail. Thus, network locality and robustness are the most desirable properties of a peer-to-peer network for sharing measurements. Although some unstructured overlays provide localised access, they fail to reach rarely located data items. Relevant measurement data may be hard to find when a client seeks measurements about a niche network element (e.g. obscure server) or seeks measurements that are highly relevant to itself by virtue of having been made by nearby nodes. Consequently, structured overlays are chosen because they can locate a rare data item deterministically and they can perform well during network failures. In structured peer-to-peer overlays, Tapestry, Pastry and Chord with Proximity Neighbour Selection, iii were studied due to their explicit notion of locality. To differentiate the level of locality and resiliency in these protocols, P2Psim simulations were performed. The results show that Tapestry is the more suitable peer-to-peer substrate for building such an application due to its superior localizing data performance. Furthermore, due to the routing similarity between Tapestry and Pastry, an implementation that shares network measurement information was developed on Freepastry, verifying the feasibility of the application. This project also contributes by extending P2Psim to integrate it with the GT-ITM network topology generator and by enabling simulation of link failures. iv Table of Contents Acknowledgement ..........................................................................................................i Abstract..........................................................................................................................ii Table of Contents ..........................................................................................................iv Chapter 1 Introduction ...................................................................................................1 1.1. Background and motivation...........................................................................1