P2P Group Management Systems: A Conceptual Analysis

Peer-to-Peer (P2P) networks are becoming eminent platforms for both distributed computing and interpersonal communication. Their role in contemporary multimedia content delivery and communication systems is strong, as witnessed by many popular applications and services. Groups in P2P systems can originate from the relations between humans, or they can be defined with purely technical criteria such as proximity. In this article, we present a conceptual analysis of P2P group management systems. We illustrate how groups are formed using different P2P system architectures, and analyze the advantages and disadvantages of using each P2P system architecture for implementing P2P group management. The evaluation criteria in the analysis are performance, robustness, fairness, suitability for battery-powered devices, scalability, and security. The outcome of the analysis facilitates the selection of an appropriate P2P system architecture for implementing P2P group management in both further research and prototype development

Inferring Network Usage from Passive Measurements in ISP Networks: Bringing Visibility of the Network to Internet Operators

The Internet is evolving with us along the time, nowadays people are more dependent of it, being used for most of the simple activities of their lives. It is not uncommon use the Internet for voice and video communications, social networking, banking and shopping. Current trends in Internet applications such as Web 2.0, cloud computing, and the internet of things are bound to bring higher traffic volume and more heterogeneous traffic. In addition, privacy concerns and network security traits have widely promoted the usage of encryption on the network communications. All these factors make network management an evolving environment that becomes every day more difficult. This thesis focuses on helping to keep track on some of these changes, observing the Internet from an ISP viewpoint and exploring several aspects of the visibility of a network, giving insights on what contents or services are retrieved by customers and how these contents are provided to them. Generally, inferring these information, it is done by means of characterization and analysis of data collected using passive traffic monitoring tools on operative networks. As said, analysis and characterization of traffic collected passively is challenging. Internet end-users are not controlled on the network traffic they generate. Moreover, this traffic in the network might be encrypted or coded in a way that is unfeasible to decode, creating the need for reverse engineering for providing a good picture to the Internet operator. In spite of the challenges, it is presented a characterization of P2P-TV usage of a commercial, proprietary and closed application, that encrypts or encodes its traffic, making quite difficult discerning what is going on by just observing the data carried by the protocol. Then it is presented DN-Hunter, which is an application for rendering visible a great part of the network traffic even when encryption or encoding is available. Finally, it is presented a case study of DNHunter for understanding Amazon Web Services, the most prominent cloud provider that offers computing, storage, and content delivery platforms. In this paper is unveiled the infrastructure, the pervasiveness of content and their traffic allocation policies. Findings reveal that most of the content residing on cloud computing and Internet storage infrastructures is served by one single Amazon datacenter located in Virginia despite it appears to be the worst performing one for Italian users. This causes traffic to take long and expensive paths in the network. Since no automatic migration and load-balancing policies are offered by AWS among different locations, content is exposed to outages, as it is observed in the datasets presented

Development of a system compliant with the Application-Layer Traffic Optimization Protocol

Dissertação de mestrado integrado em Engenharia InformáticaWith the ever-increasing Internet usage that is following the start of the new decade, the need to optimize this world-scale network of computers becomes a big priority in the technological sphere that has the number of users rising, as are the Quality of Service (QoS) demands by applications in domains such as media streaming or virtual reality. In the face of rising traffic and stricter application demands, a better understand ing of how Internet Service Providers (ISPs) should manage their assets is needed. An important concern regards to how applications utilize the underlying network infras tructure over which they reside. Most of these applications act with little regard for ISP preferences, as exemplified by their lack of care in achieving traffic locality during their operation, which would be a preferable feature for network administrators, and that could also improve application performance. However, even a best-effort attempt by applications to cooperate will hardly succeed if ISP policies aren’t clearly commu nicated to them. Therefore, a system to bridge layer interests has much potential in helping achieve a mutually beneficial scenario. The main focus of this thesis is the Application-Layer Traffic Optimization (ALTO) work ing group, which was formed by the Internet Engineering Task Force (IETF) to explore standardizations for network information retrieval. This group specified a request response protocol where authoritative entities provide resources containing network status information and administrative preferences. Sharing of infrastructural insight is done with the intent of enabling a cooperative environment, between the network overlay and underlay, during application operations, to obtain better infrastructural re sourcefulness and the consequential minimization of the associated operational costs. This work gives an overview of the historical network tussle between applications and service providers, presents the ALTO working group’s project as a solution, im plements an extended system built upon their ideas, and finally verifies the developed system’s efficiency, in a simulation, when compared to classical alternatives.Com o acrescido uso da Internet que acompanha o início da nova década, a necessidade de otimizar esta rede global de computadores passa a ser uma grande prioridade na esfera tecnológica que vê o seu número de utilizadores a aumentar, assim como a exigência, por parte das aplicações, de novos padrões de Qualidade de Serviço (QoS), como visto em domínios de transmissão de conteúdo multimédia em tempo real e em experiências de realidade virtual. Face ao aumento de tráfego e aos padrões de exigência aplicacional mais restritos, é necessário melhor compreender como os fornecedores de serviços Internet (ISPs) devem gerir os seus recursos. Um ponto fulcral é como aplicações utilizam os seus recursos da rede, onde muitas destas não têm consideração pelas preferências dos ISPs, como exemplificado pela sua falta de esforço em localizar tráfego, onde o contrário seria preferível por administradores de rede e teria potencial para melhorar o desempenho aplicacional. Uma tentativa de melhor esforço, por parte das aplicações, em resolver este problema, não será bem-sucedida se as preferências administrativas não forem claramente comunicadas. Portanto, um sistema que sirva de ponte de comunicação entre camadas pode potenciar um cenário mutuamente benéfico. O foco principal desta tese é o grupo de trabalho Application-Layer Traffic Optimization (ALTO), que foi formado pelo Internet Engineering Task Force (IETF) para explorar estandardizações para recolha de informação da rede. Este grupo especificou um protocolo onde entidades autoritárias disponibilizam recursos com informação de estado de rede, e preferências administrativas. A partilha de conhecimento infraestrutural é feita para possibilitar um ambiente cooperativo entre redes overlay e underlay, para uma mais eficiente utilização de recursos e a consequente minimização de custos operacionais. É pretendido dar uma visão da histórica disputa entre aplicações e ISPs, assim como apresentar o projeto do grupo de trabalho ALTO como solução, implementar e melhorar sobre as suas ideias, e finalmente verificar a eficiência do sistema numa simulação, quando comparado com alternativas clássicas

A framework for the dynamic management of Peer-to-Peer overlays

Peer-to-Peer (P2P) applications have been associated with inefficient operation, interference with other network services and large operational costs for network providers. This thesis presents a framework which can help ISPs address these issues by means of intelligent management of peer behaviour. The proposed approach involves limited control of P2P overlays without interfering with the fundamental characteristics of peer autonomy and decentralised operation. At the core of the management framework lays the Active Virtual Peer (AVP). Essentially intelligent peers operated by the network providers, the AVPs interact with the overlay from within, minimising redundant or inefficient traffic, enhancing overlay stability and facilitating the efficient and balanced use of available peer and network resources. They offer an “insider‟s” view of the overlay and permit the management of P2P functions in a compatible and non-intrusive manner. AVPs can support multiple P2P protocols and coordinate to perform functions collectively. To account for the multi-faceted nature of P2P applications and allow the incorporation of modern techniques and protocols as they appear, the framework is based on a modular architecture. Core modules for overlay control and transit traffic minimisation are presented. Towards the latter, a number of suitable P2P content caching strategies are proposed. Using a purpose-built P2P network simulator and small-scale experiments, it is demonstrated that the introduction of AVPs inside the network can significantly reduce inter-AS traffic, minimise costly multi-hop flows, increase overlay stability and load-balancing and offer improved peer transfer performance

Un environnement pour le calcul intensif pair à pair

Le concept de pair à pair (P2P) a connu récemment de grands développements dans les domaines du partage de fichiers, du streaming vidéo et des bases de données distribuées. Le développement du concept de parallélisme dans les architectures de microprocesseurs et les avancées en matière de réseaux à haut débit permettent d'envisager de nouvelles applications telles que le calcul intensif distribué. Cependant, la mise en oeuvre de ce nouveau type d'application sur des réseaux P2P pose de nombreux défis comme l'hétérogénéité des machines, le passage à l'échelle et la robustesse. Par ailleurs, les protocoles de transport existants comme TCP et UDP ne sont pas bien adaptés à ce nouveau type d'application. Ce mémoire de thèse a pour objectif de présenter un environnement décentralisé pour la mise en oeuvre de calculs intensifs sur des réseaux pair à pair. Nous nous intéressons à des applications dans les domaines de la simulation numérique et de l'optimisation qui font appel à des modèles de type parallélisme de tâches et qui sont résolues au moyen d'algorithmes itératifs distribués or parallèles. Contrairement aux solutions existantes, notre environnement permet des communications directes et fréquentes entre les pairs. L'environnement est conçu à partir d'un protocole de communication auto-adaptatif qui peut se reconfigurer en adoptant le mode de communication le plus approprié entre les pairs en fonction de choix algorithmiques relevant de la couche application ou d'éléments de contexte comme la topologie au niveau de la couche réseau. Nous présentons et analysons des résultats expérimentaux obtenus sur diverses plateformes comme GRID'5000 et PlanetLab pour le problème de l'obstacle et des problèmes non linéaires de flots dans les réseaux. ABSTRACT : The concept of peer-to-peer (P2P) has known great developments these years in the domains of file sharing, video streaming or distributed databases. Recent advances in microprocessors architecture and networks permit one to consider new applications like distributed high performance computing. However, the implementation of this new type of application on P2P networks gives raise to numerous challenges like heterogeneity, scalability and robustness. In addition, existing transport protocols like TCP and UDP are not well suited to this new type of application. This thesis aims at designing a decentralized and robust environment for the implementation of high performance computing applications on peer-to-peer networks. We are interested in applications in the domains of numerical simulation and optimization that rely on tasks parallel models and that are solved via parallel or distributed iterative algorithms. Unlike existing solutions, our environment allows frequent direct communications between peers. The environment is based on a self adaptive communication protocol that can reconfigure itself dynamically by choosing the most appropriate communication mode between any peers according to decisions concerning algorithmic choice made at the application level or elements of context at transport level, like topology. We present and analyze computational results obtained on several testeds like GRID’5000 and PlanetLab for the obstacle problem and nonlinear network flow problems

Static Web content distribution and request routing in a P2P overlay

The significance of collaboration over the Internet has become a corner-stone of modern computing, as the essence of information processing and content management has shifted to networked and Webbased systems. As a result, the effective and reliable access to networked resources has become a critical commodity in any modern infrastructure. In order to cope with the limitations introduced by the traditional client-server networking model, most of the popular Web-based services have employed separate Content Delivery Networks (CDN) to distribute the server-side resource consumption. Since the Web applications are often latency-critical, the CDNs are additionally being adopted for optimizing the content delivery latencies perceived by the Web clients. Because of the prevalent connection model, the Web content delivery has grown to a notable industry. The rapid growth in the amount of mobile devices further contributes to the amount of resources required from the originating server, as the content is also accessible on the go. While the Web has become one of the most utilized sources of information and digital content, the openness of the Internet is simultaneously being reduced by organizations and governments preventing access to any undesired resources. The access to information may be regulated or altered to suit any political interests or organizational benefits, thus conflicting with the initial design principle of an unrestricted and independent information network. This thesis contributes to the development of more efficient and open Internet by combining a feasibility study and a preliminary design of a peer-to-peer based Web content distribution and request routing mechanism. The suggested design addresses both the challenges related to effectiveness of current client-server networking model and the openness of information distributed over the Internet. Based on the properties of existing peer-to-peer implementations, the suggested overlay design is intended to provide low-latency access to any Web content without sacrificing the end-user privacy. The overlay is additionally designed to increase the cost of censorship by forcing a successful blockade to isolate the censored network from the rest of the Internet

Understand the Similarity of Internet Service Providers via Peer-to-Peer User Interest Analysis

University of Minnesota M.S. thesis. June 2019. Major: Computer Science. Advisor: Haiyang Wang. 1 computer file (PDF); 63 pages.Internet traffic continues to exhibit exponential growth in the past few years. This forces Internet service providers(ISPs) to continuously invest in infrastructure upgrades and deploy traffic management techniques, such as caching and locality, to fulfill the increasing user demand. To help ISPs better manage their infrastructures, it is important to compare and understand the similarity of their user interests. However, such a comparison is challenging because the ISP data is hard to obtain, not to mention the related modeling and analysis issues. In this thesis, we aim to understand the ISP similarity through an extensive analysis of Peer-to-Peer(P2P) user interest. To collect the P2P dataset, we develop a tool to automatically download BitTorrent's meta-info(torrent) files on the Internet. This tool also helps us to collect important peer and content information in these BitTorrent swarms without uploading any copyrighted files. As a result, we successfully obtained 16,697 active peers from 1,721 torrents in 1,097 unique Autonomous Systems(ASes). After that, we adopt the classic statistical and clustering approaches to compare their different user interests. Our research for the first time shows the existence of cloud users in such real-world content distribution systems as BitTorrent. The model analysis further indicates that we can adopt similar traffic management approaches (e.g., caching similar contents) across geographically closer ASes