Dissertations / Theses on the topic 'Peer-to-Peer (P2P) Overlay'

Hermes é um arcabouço para a programação de aplicações P2P. Com ele, pode-se criar diversos tipos de aplicações distribuídas, sem se preocupar com a camada de comunicação. O Hermes não é uma implementação de uma rede de sobreposição P2P, e sim uma camada acima das implementações já existentes. O desenvolvedor da aplicação fica isolado da implementação da rede de sobreposição utilizada. Esse isolamento é feito de forma tal que não há limitações quanto à arquitetura de rede utilizada pela implementação, seja ela centralizada, descentralizada, distribuída estruturada ou distribuída não-estruturada. Entre os serviços oferecidos pelo Hermes estão: troca de mensagens, busca, comunicação em grupo e armazenamento distribuído. Geralmente, no início do desenvolvimento de uma aplicação distribuída, tem-se poucas informações sobre o seu tamanho final ou perfil de utilização. O Hermes possibilita ao desenvolvedor da aplicação adiar, até o momento da efetiva implantação do sistema, a decisão sobre qual arquitetura de rede ou qual implementação de rede de sobreposição são as mais apropriadas para suas necessidades. Possibilita também, quando o perfil de utilização muda com o tempo, a troca da implementação utilizada por uma outra que se adeque mais ao novo perfil sem alterações no código da aplicação.
Hermes is a framework for P2P application programming. Using it, one can create several kinds of distributed applications without worrying about the underlying network. Hermes is not a P2P overlay network implementation, but a shell envolving existing implementations. The application developer is isolated from the implementation of the overlay network in use. This isolation is done in a way that poses no limitations on the network architecture used, which may be centralized, decentralized, structured or unstructured. Amongst the services offered by Hermes are: message exchange, search, group communication, and distributed storage. In the early stages of the development of a distributed application, information as to its final size or utilization profile is often unknown. Hermes gives the application developer the possibility of delaying, until the actual moment of system deployment, the decision as to which network architecture or which overlay network implementation is the most appropriate. It also gives the developer the choice, when utilization profile changes over time, of replacing the network implementation with one more suitable to the application needs, without changes on the application code.

Today, with widespread use of Internet in many areas, the common procedures frequently encountered in business life such as contracting and negotiation need to be automated. The distributed structure of the Internet and the difficulty of resources dispersed on one center makes such a system to have a distributed architecture . In this study, for first time, automatization of a contracting form through business processes was proposed and was carried out. A peer to peer process contracting overlay what we call Peer-Con is developed. The system is an extension of Java Agent Development Framework (JADE) and uses IEEE Foundation for Intelligent Physical Agents (FIPA) Agent Communication Language (ACL) standard. Cost aware flexible representation of process capabilities
description of an operator to decide on whether given capabilities turnout to an agreement or not and self organization of peer connectivity for better contracting performance are distinguishing features of the system. The system can easily be adapted to different domains while the core functionality remains the same. Practical use of Peer-Con is shown by two applications from different domains
Driving Route Calculation on Web Maps and Digital Signal Processing Module (DSPM) product planning domain.

This report concerns the implementation of a simulation framework to evaluate an emerging peer-to-peer network topology scheme using 8-point hypercircles, entitled HyperCircle. This topology was proposed in order to alleviate some of the drawbacks of current P2P systems evolving in an uncontrolled manner, such as scalability issues, network overload and long search times. The framework is supposed to be used to evaluate the advantages of this new topology. The framework has been built on top of an existing simulator software solution, the selection of which was an important part of the development. Weighing different variables such as scalability and API usability, the selection fell on OverSim, an open-source discreet-event simulator based on OMNET++.

After formalizing the protocol for easier implementation, as well as extending it for better performance, implementation followed using C++ with OverSim’s API and simulation library. Implemented as a module (alongside other stock modules providing their own protocols such as Chord and Kademlia), it can be used in OverSim to simulate a user-defined network using one of the simulation routine applications provided (or using a custom application written by the user). For the purposes of this thesis, the standard application KBRTestApp was used; an application sending test messages between randomly selected nodes, while adding and removing nodes at specific time intervals. The adding and removing of nodes can be configured with probability parameters.

Tentative testing shows that this implementation of the HyperCircle protocol has a certain performance gain over the OverSim implementations of the Chord and Kademlia protocols, measurable in the time it takes a message to get from sender to recipient. Further testing is outside the scope of this thesis.

The wide-spread coverage and ubiquitous presence of mobile networks has propelled the usage and adoption of mobile phones to an unprecedented level around the globe. The computing capabilities of these mobile phones have improved considerably, supporting a vast range of third party applications. Simultaneously, Peer-to-Peer (P2P) overlay networks have experienced a tremendous growth in terms of usage as well as popularity in recent years particularly in fixed wired networks. In particular, Distributed Hash Table (DHT) based Structured P2P overlay networks offer major advantages to users of mobile devices and networks such as scalable, fault tolerant and self-managing infrastructure which does not exhibit single points of failure. Integrating P2P overlays on the mobile network seems a logical progression; considering the popularities of both technologies. However, it imposes several challenges that need to be handled, such as the limited hardware capabilities of mobile phones and churn (i.e. the frequent join and leave of nodes within a network) intensive mobile networks offering limited yet expensive bandwidth availability. This thesis investigates the feasibility of extending P2P to mobile networks so that users can take advantage of both these technologies: P2P and mobile networks. This thesis utilises OverSim, a P2P simulator, to experiment with the performance of various P2P overlays, considering high churn and bandwidth consumption which are the two most crucial constraints of mobile networks. The experiment results show that Kademlia and EpiChord are the two most appropriate P2P overlays that could be implemented in mobile networks. Furthermore, Network Address Translation (NAT) is a major barrier to the adoption of P2P overlays in mobile networks. Integrating NAT traversal approaches with P2P overlays is a crucial step for P2P overlays to operate successfully on mobile networks. This thesis presents a general approach of NAT traversal for ring based overlays without the use of a single dedicated server which is then implemented in OverSim. Several experiments have been performed under NATs to determine the suitability of the chosen P2P overlays under NATed environments. The results show that the performance of these overlays is comparable in terms of successful lookups in both NATed and non-NATed environments; with Kademlia and EpiChord exhibiting the best performance. The presence of NATs and also the level of churn in a network influence the routing techniques used in P2P overlays. Recursive routing is more resilient to IP connectivity restrictions posed by NATs but not very robust in high churn environments, whereas iterative routing is more suitable to high churn networks, but difficult to use in NATed environments. Kademlia supports both these routing schemes whereas EpiChord only supports the iterating routing. This undermines the usefulness of EpiChord in NATed environments. In order to harness the advantages of both routing schemes, this thesis presents an adaptive routing scheme, called Churn Aware Routing Protocol (ChARP), combining recursive and iterative lookups where nodes can switch between recursive and iterative routing depending on their lifetimes. The proposed approach has been implemented in OverSim and several experiments have been carried out. The experiment results indicate an improved performance which in turn validates the applicability and suitability of ChARP in NATed environments.

Due to its ability to deliver scalable and fault-tolerant solutions, applications based on the peer-to-peer (P2P) paradigm are used by millions of users on the internet. Recently, wireless mesh networks (WMNs) have attracted a lot of interest from both academia and industry, because of their potential to provide flexible and alternative broadband wireless internet connectivity. However, due to various reasons such as unstable wireless link characteristics and multi-hop forwarding operation, the performance of current P2P systems is rather low in WMNs. This dissertation studies the technological challenges involved while deploying P2P systems over WMNs. We study the benefits of location-awareness and resource replication to the P2P overlay while targeting efficient resource lookup in WMNs. We further propose a cross-layer information exchange between the P2P overlay and the WMN in order to reduce resource lookup delay by augmenting the overlay routing table with physical neighborhood and resource lookup history information. Aiming to achieve throughput maximization and fairness in P2P systems, we model the peer selection problem as a mathematical optimization problem by using a set of mixed integer linear equations. A study of the model reveals the relationship between peer selection, resource replication and channel assignment on the performance of P2P systems over WMNs. We extend the model by formulating the P2P download problem as chunk scheduling problem. As a novelty, we introduce constraints to model the capacity limitations of the network due to the given routing and channel assignment strategy. Based on the analysis of the model, we propose a new peer selection algorithm which incorporates network load information and multi-path routing capability. By conducting testbed experiments, we evaluate the achievable throughput in multi-channel multi-radio WMNs. We show that the adjacent channel interference (ACI) problem in multi-radio systems can be mitigated, making better use of the available spectrum. Important lessons learned are also outlined in order to design practical channel and channel bandwidth assignment algorithms in multi-channel multi-radio WMNs.

O gerenciamento das redes de comunicações modernas frequentemente requer que operadores de diferentes domínios administrativos interajam uns com os outros de modo a realizar uma tarefa de gerenciamento de maneira cooperativa. Nesse contexto, pode-se observar que há distribuição tanto na execução das ações como na tomada das decisões pelos operadores participantes da sessão de gerenciamento. As soluções tradicionais de gerenciamento de redes praticamente não oferecem suporte algum ao gerenciamento baseado na cooperação entre humanos, pois foram concebidas levando em consideração um único domínio administrativo sendo gerenciado por um único operador ou por um grupo de operadores pertencentes a uma mesma organização. Visando solucionar esse problema, é introduzido nesse trabalho o uso de tecnologias peer-to-peer (P2P) em soluções de gerenciamento de redes de modo a permitir o gerenciamento baseado na cooperação entre humanos. Nessa abordagem, operadores de rede usam ferramentas híbridas que, ao mesmo tempo, gerenciam os seus domínios locais e fazem parte de um sistema P2P de gerenciamento. A proposta de gerenciamento apresentada foi implementada através de uma ferramenta chamada ManP2P, a qual combina funcionalidades de gerenciamento de redes e trabalho cooperativo.
Modern networks not rarely require human operators from different administrative domains to interact with one another in order to accomplish a management task in a cooperative fashion. In this scenario one observes that not only management actions are executed in a distributed way, but also the management decisions are cooperatively taken by all autonomous operators participating in a management session. Traditional management solutions fail to support human centered cooperative management because they were conceived considering a single administrative domain being managed by a single operator or by a group of operators belonging to the same organization. In order to address this issue, we introduce in this paper the use of peer-to-peer (P2P) technologies in network management solutions to enable human-centered cooperative management. In this approach, network operators use hybrid tools that both manage their local domains and are peers of an overlay management system. We have implemented the proposed management approach through a tool called ManP2P, which combines network management and groupware functionalities.

Made available in DSpace on 2014-12-17T14:55:03Z (GMT). No. of bitstreams: 1 MarcosCMAP.pdf: 634837 bytes, checksum: 4a0393d7f7dbe297fda66b1ed1859c99 (MD5) Previous issue date: 2006-02-20
There are some approaches that take advantage of unused computational resources in the Internet nodes - users? machines. In the last years , the peer-to-peer networks (P2P) have gaining a momentum mainly due to its support for scalability and fault tolerance. However, current P2P architectures present some problems such as nodes overhead due to messages routing, a great amount of nodes reconfigurations when the network topology changes, routing traffic inside a specific network even when the traffic is not directed to a machine of this network, and the lack of a proximity relationship among the P2P nodes and the proximity of these nodes in the IP network. Although some architectures use the information about the nodes distance in the IP network, they use methods that require dynamic information. In this work we propose a P2P architecture to fix the problems afore mentioned. It is composed of three parts. The first part consists of a basic P2P architecture, called SGrid, which maintains a relationship of nodes in the P2P network with their position in the IP network. Its assigns adjacent key regions to nodes of a same organization. The second part is a protocol called NATal (Routing and NAT application layer) that extends the basic architecture in order to remove from the nodes the responsibility of routing messages. The third part consists of a special kind of node, called LSP (Lightware Super-Peer), which is responsible for maintaining the P2P routing table. In addition, this work also presents a simulator that validates the architecture and a module of the Natal protocol to be used in Linux routers
Entre as diversas abordagens para se aproveitar os recursos computacionais ociosos existentes nas folhas da Internet, ou seja, nas m?quinas dos usu?rios, as redes peer-to-peer (P2P) v?m ganhando destaque especial nos ?ltimos anos devido principalmente ? sua escalabilidade, desempenho e toler?ncia ? falhas. As arquiteturas P2P atuais, entretanto, ainda apresentam alguns problemas como a sobrecarga nos n?s devido ? realiza??o do roteamento de mensagens, o n?mero elevado de n?s reconfigurados devido ? mudan?as de topologia da rede, a exist?ncia de tr?fego de roteamento dentro das redes das organiza??es que n?o ? destinado a nenhuma de suas m?quinas e ? aus?ncia de rela??o entre a proximidade dos n?s na rede P2P e a proximidade desses n?s na rede IP. Embora algumas arquiteturas considerem essas dist?ncias na rede IP, o fazem atrav?s de m?todos que requerem a troca de informa??es constantemente. Nesse trabalho n?s propomos uma arquitetura P2P para resolver os problemas citados. Essa arquitetura ? composta por tr?s partes. A primeira parte consiste em uma arquitetura P2P b?sica, chamada SGrid, que mant?m a rela??o dos n?s na rede P2P com suas posi??es na rede IP e atribui regi?es de chaves adjacentes para n?s de uma mesma organiza??o. A segunda parte consiste em um protocolo chamado NATal (Routing and NAT application layer) que estende a arquitetura b?sica para retirar dos n?s a fun??o de roteamento de mensagens. A terceira parte consiste de um tipo especial de n?, chamado LSP (Lightware Super-Peer), que ? o respons?vel pela manuten??o das tabelas de roteamento P2P. Al?m da descri??o da arquitetura proposta e da especifica??o dos protocolos SGrid e NATal, esse trabalho apresenta o simulador desenvolvido para validar a arquitetura e um m?dulo para ser utilizado em roteadores Linux que implementa o protocolo Natal

Le routage par clé et par contenu sont des systèmes de routage ou la destination d'un message suit un parcours entre les nœuds du réseau qui dépend seulement du contenu du message même. On peut les trouver utilisés soit dans des systèmes pair-à-pair connus comme Réseaux Overlay Structurés (Structured Overlay Networks, SON), soit dans les architecture internet de nouvelle génération, les Réseaux Centrés sur les Contenus (Content-Centric Networks, CCN). Le but de cette thèse est double. D'un côté, on explore le sujet de l'interconnexion et de la coopération des réseaux d'overlay, et on propose une architecture capable de permettre à plusieurs réseaux d'overlay hétérogènes, avec différentes topologies et différents mécanismes de routage, d'interagir, grâce à une infrastructure basée sur des nœuds passerelles. On montre, par des moyennes de simulation et déploiement dans un réseaux réel, que la solution est scalable et permet un routage quasi-exhaustif avec un nombre relativement bas des nœuds passerelle bien connectés. De plus, on présente deux exemples d'applications qui pourront bénéficier de cette architecture. Dans une deuxième partie, on rentre plutôt dans les possibilités offertes par le routage basé sur les contenus hors sa "zone de confort": d'abord, on analyse les améliorations qu'un réseau d'overlay structuré peut porter à un système de diffusion vidéo pair-à-pair, en termes de qualité du vidéo et de perte des paquets pendant la transmission. Après, on examine un système entièrement centré sur le routage basé sur les contenus, en développant une solution de diffusion vidéo en temps réel dans un réseau CCN.

L'accès à n'importe quel type de service, depuis n'importe quel type de terminal, en étant connecté sur n'importe quel type de réseau est devenu possible. Cependant avec la diversité des réseaux et des terminaux, l'adaptation de contenu est devenue une problématique majeure. Cette thèse définit une solution de nœud intermédiaire, dénommé Potacco pour nœud POlymorphique Transparent pour l'Adaptation de Contenu adapté au COntexte, flexible permettant l’adaptation dynamique de tout type de contenu en fonction du contexte de l'utilisateur. Ce nœud collecte et met à disposition le contexte courant, gère/coordonne les modules applicatifs et les collecteurs de contexte, permet le déploiement sécurisé de code, peut être transparent. Des démonstrateurs de ce nœud générique, intégré dans un réseau physique puis dans un réseau overlay de services et P2P constituent une preuve de concept. Des simulations et expérimentations réelles ont permis d'évaluer ces solutions
With the evolution of fixed and mobile networks, the increasing number of diversified devices, it is now possible to access any type of services, from any type of devices, being connected to any type of networks. By adding the wish of users to receive personalized contents, adapting content has become a major problem. To help to reach this goal, this thesis defines an intermediate flexible node, allowing dynamic adaptation of any type of content depending on the context of the users. This study resulted in the definition of a node architecture, called Potacco (for noeud POlymorphique Transparent pour l'Adaptation de Contenu adapté au COntexte, in French or Transparent Polymorphic node for content adaptation to the context in English) and its implementation and validation. This node: · collects and provides current context information to enable application modules to make adaptation based on such values · manages/coordinates the application modules and the context collectors (e. G. Context sensors) · enables the secured deployment of code in the node (the supplier code, but also the target node are authenticated) · may be transparent to the applications and may process data without no mean for the endpoints to detect it. Two demonstrators have been implemented as a proof of concept of this generic node being located in a physical network: as a wired/wireless gateway performing media content adaptation and as a node in an ADSL network inserting transparently the users’ context. Then, the use of that node in "overlay" networks has been the subject of a new proof of concept. Two cases were studied: the first one for the provisioning of services adapted to the user’s context in a service specific overlay network service, where a case of a personalized IPTV service is presented, and the second one related to the content adaptation of multimedia stream broadcasted on a P2P network where the Potacco node itself is a member of the P2P network. Validation by simulation and real experiments, permitted to evaluate these solutions

Hui Ying Kin.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2004.
Includes bibliographical references (leaves 62-64).
Abstracts in English and Chinese.
Chapter 1 --- Introduction --- p.10
Chapter 1.1 --- Motivation --- p.10
Chapter 1.2 --- P2P small-world solution --- p.11
Chapter 1.3 --- Balance of this thesis --- p.12
Chapter 2 --- Background --- p.13
Chapter 2.1 --- Small World phenomenon --- p.13
Chapter 2.2 --- Internet Flash Crowds --- p.16
Chapter 2.3 --- Dynamics in the small world network --- p.17
Chapter 3 --- Small-world Overlay Protocol --- p.19
Chapter 3.1 --- Overview --- p.23
Chapter 3.2 --- Join Cluster Protocol (JCP): --- p.25
Chapter 3.3 --- Leave Cluster Protocol (LCP): --- p.29
Chapter 3.4 --- Object Lookup Protocol (OLP): --- p.31
Chapter 3.5 --- Experimental Results Of Comparing with Other Structured P2P Networks --- p.33
Chapter 3.5.1 --- Performance of object lookup: --- p.33
Chapter 3.5.2 --- Effect of object lookup performance under different net- work sizes and number of long links: --- p.34
Chapter 3.5.3 --- Comparison of Clustering Coefficient: --- p.35
Chapter 4 --- Protocols for Handling Flash Crowd --- p.39
Chapter 4.1 --- Static Flash Crowd --- p.40
Chapter 4.2 --- Dynamic Flash Crowd --- p.44
Chapter 4.3 --- Experimental Results for Replicating Popular Object --- p.45
Chapter 4.3.1 --- Comparison between Chord and SWOP --- p.46
Chapter 4.3.2 --- Comparison on Queue Size --- p.48
Chapter 4.3.3 --- Variation on object request rate --- p.49
Chapter 4.3.4 --- Variation on Number of Long Link Neighbors (k) --- p.50
Chapter 4.4 --- Experiment Results for Examining the Effects on Traffic Loadings --- p.51
Chapter 5 --- Performance Analysis --- p.53
Chapter 5.1 --- Lookup complexity of SWOP --- p.53
Chapter 5.2 --- Average time used for replicating item to all clusters in SWOP --- p.56
Chapter 6 --- Related Work --- p.59
Chapter 7 --- Conclusion --- p.61

The rapid growth of peer-to-peer (P2P) networks in the past few years has brought with it increases in transit cost to Internet Service Providers (ISPs), as peers exchange large amounts of traffic across ISP boundaries. This ISP oblivious behavior has resulted in misalignment of incentives between P2P networks|that seek to maximize user quality|and ISPs|that would seek to minimize costs. Can we design a P2P overlay that accounts for both ISP costs as well as quality of service, and attains a desired tradeoff between the two? We design a system, which we call MultiTrack, that consists of an overlay of multiple kinds of Trackers whose purpose it is to align these goals. We have mTrackers that form an overlay network among themselves, and split demand from users among different ISP domains while trying to minimize their individual costs (delay plus transit cost) in their ISP domain. We design the signals in this overlay of mTrackers in such a way that potentially competitive individual optimization goals are aligned across the mTrackers. The system could also have a tTracker that acts as a gateway into the system, and ensures that users who are from different ISP domains have a fair chance of being admitted into the system, while keeping costs in check. We prove analytically that our system is stable and achieves maximum utility with minimum cost. We validated our system design using Matlab simulations, and implemented the system on ns-2 in order to conduct more realistic experiments. We showed that our system significantly outperforms two types of systems, one in which user delay is the only control dimension (forwarding traffic without considering the transit prices) and a second system in which transit prices are the only control dimension (localized traffic only). Thus, we conclude that our system, that operates in two dimensions: (1) user delay and (2) transit prices, results in minimum cost and maximum utility for fixed capacity of the system.

Η διπλωματική εργασία διαπραγματεύεται την εφαρμοσιμότητα του peer-to-peer υπολογισμού και τεχνικών στα ασύρματα κινητά ad-hoc δίκτυα και στα δίκτυα αισθητήρων. Παρουσιάζεται μια παραλλαγή ενός νέου P2P πρωτοκόλλου (Energy Level Distributed Tree) που σαν κύρια λειτουργία του έχει την αύξηση του προσδόκιμου λειτουργίας ενός δικτύου αισθητήρων. Επίσης, γίνεται αναφορά στα πιο δημοφιλή εργαλεία προσομοίωσης για P2P πρωτόκολλα δρομολόγησης και παρουσιάζεται ένα νέο εργαλείο, d-p2p-sim, με δυνατότητα προσομοίωσης εκατομμυρίων κόμβων. Τέλος, εξετάζουμε την απόδοση ενός νέου P2P πρωτοκόλλου δρομολόγησης, του Nested Balanced Distributed Tree, που απαντά με βέλτιστο τρόπο ερωτήμα ακριβούς ταιριάσματος και ερωτήματα διαστήματος παρουσιάζοντας παράλληλα δύο νέους αλγορίθμους αναζήτησης για αυτό.
In this master thesis we study the applicability of the peer-to-peer computing and techniques on wireless ad-hoc networks and sensor-nets. We propose a simplified mapping of an optimal P2P protocol (NBDT) onto sensor-nets, the so called Energy Level Distributed Tree (ELDT), which has one main operation: the life expectancy of a sensor-net. Furthermore, are examined the most popular Peer-to-Peer simulators and is presented a new distributed simulator for P2P routing algorithms. The key feature of the proposed simulator is the ability to simulate millions of peers. Finally, is presented a revised version of the NBDT protocol which is hot-spot free and achieves a better load distribution introducing a negligible routing overhead.

No
The FIRE trust and reputation model is a de-centralized trust model that can be applied for trust management in unstructured Peer-to-Peer (P2P) overlays. The FIRE model does not, however, consider malicious activity and possible collusive behavior in nodes of network and it is therefore susceptible to collusion attacks. This investigation reveals that FIRE is vulnerable to lying and cheating attacks and presents a trust management approach to detect collusion in direct and witness interactions among nodes based on colluding node's history of interactions. A witness ratings based graph building approach is utilized to determine possibly collusive behavior among nodes. Furthermore, various interaction policies are defined to detect and prevent collaborative behavior in colluding nodes. Finally a multidimensional trust model FIRE+ is devised for avoiding collusion attacks in direct and witness based interactions. The credibility of the proposed trust management scheme as an enhancement of the FIRE trust model is verified by extensive simulation experiments.