Dissertations / Theses on the topic 'Hybrid peer-to-peer'

This thesis provides an introduction to the MMORPG genre, and the challenges of engineering a networking system supporting these games, as well as the state of the art titles that exist on the market today. Further it describes the design and development of a peer-to-peer networking system to support MMORPG games, and basic testing of this system. It focuses on a broad theoretical approach to provide a solid background to understand the options available and choices made in the design of the system. The thesis presents a hybrid peer-to-peer concept that aims to reduce costs of operating an MMORPG, allowing smaller game developers to compete against major titles. It includes the main features that should be enabled in a distributed MMORPG architecture. The concept is designed to be flexible in terms of further development, allowing new features to be added with ease and providing game designers with multiple options. A proof-of-concept demo is implemented in Java, displaying the features through a simple interface, and tests showed that the concept has potential to challenge the client-server solutions that are dominating the market today.

In this thesis, the problems caused by peer behavior in peer-to-peer (P2P) video streaming is investigated. First, peer behaviors are modeled using two dimensional continuous time markov chains to investigate the reliability of P2P video streaming systems. Then a metric is proposed to evaluate the dynamic behavior and evolution of P2P overlay network. Next, a hybrid geographical location-time and interest based clustering algorithm is proposed to improve the success ratio and reduce the delivery time of required content. Finally, Hybrid Fault Tolerant Video Streaming System (HFTS) over P2P networks has been designed and offered conforming the required Quality of Service (QoS) and Fault Tolerance. The results indicate that the required QoS can be achieved in streaming video applications using the proposed hybrid approach.

Together with the wide spread of network devices with broadband access, streaming has become more and more popular as the favorite mechanism for broadcasting real-time events to a large number of users. The traditional approaches to live streaming include IP multicast and client-server based streaming. Of them, IP multicast is not globally deployed while client-server streaming implies expensive bandwidth provision at the servers. Therefore, recently a lot of researches have been focused on peer-to-peer streaming solutions due to theirs ease of deployment, cost-effectiveness and scalability. In this thesis, we first describe and implement a novel algorithm which addresses the peer churn issue in live peer-to-peer streaming system. This algorithm changes the playback delay in order to keep the average loss rate within predefined values. The correctness of the algorithm as well as our implementation is then confirmed through experiments on PlanetLab. The second contribution of this thesis is an implementation of the current state of the art peer-to-peer streaming approach, Coolstreaming+, for future evaluations and improvements. The implementation is then validated through the relation between loss rate and playback delay as well as between loss rate and number of sub-streams.

Native Multicast plays an important role in distributing and managing delivery of some of the most popular Internet applications, such as IPTV and media delivery. However, due to patchy support and the existence of multiple approaches for Native Multicast, the support for Native Multicast is fragmented into isolated areas termed Multicast Islands. This renders Native Multicast unfit to be used as an Internet wide application. Instead, Application Layer Multicast, which does not have such network requirements but is more expensive in terms of bandwidth and overhead, can be used to connect the native multicast islands. This thesis proposes Opportunistic Native Multicast (ONM) which employs Application LayerMulticast (ALM), on top of a DHT-based P2P overlay network, and Automatic Multicast Tunnelling (AMT) to connect these islands. ALM will be used for discovery and initiating the AMT tunnels. The tunnels will encapsulate the traffic going between islands' Primary Nodes (PNs). AMT was used for its added benefits such as security and being better at traffic shaping and Quality Of Service (QoS). While different approaches for connecting multicast islands exists, the system proposed in the thesis was designed with the following characteristics in mind: scalability, availability, interoperability, self-adaptation and efficiency. Importantly, by utilising AMT tunnels, this approach has unique properties that improve network security and management.

Thesis (MEng)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: Massively Multiplayer Online Games are large virtual worlds co-inhabited by players over the Internet. As up to thousands of players can be simultaneously connected to the game, the server and network architectures are required to scale e ciently. The traditional client/server model results in a heavy nancial burden for operation of the server. Various alternative architectures have been proposed as a replacement for the traditional model, but the adoption of these alternatives are slow as they present their own set of challenges. The proposed hybrid system is based on many di erent architectures and peer-topeer concepts that were reviewed in the literature. It aims to provide a compromise for existing, commercially successful MMOGs to introduce peer-to-peer components into their systems with no requirement of modi cation to their server or client software. With the system's design presented, the middleware software is implemented and deployed in a real, controlled environment alongside an Ultima Online game server and its clients. The movement game mechanic was distributed amongst the peers while the others remained the responsiblity of the server. A number of performance experiments are performed to measure the e ects of the modi ed system over the original client/server system on bandwidth, latency, and hardware impact. The results revealed an increase in the server bandwidth usage by 35%, slave bandwidth usage by 17% and supernode bandwiwdth usage by 3111%. The latencies of distributed server mechanics were reduced by up to 94%, while the non-distributed latencies were increased by up to 6000%. These results suggested that a system with absolutely no modi cation to the server is unlikely to provide the desired bene ts. However, with 2 minor modi cations to the server, the middleware is able to reduce both server load and player latencies. The server bandwidth can be reduced by 39%, while the supernode's bandwidth is increased only by 1296%. The distributed latencies maintain their reduction while non-distributed latencies remain unchanged from the C/S system.
AFRIKAANSE OPSOMMING: Massiewe Multispeler Aanlyn Speletjies (MMAS) is groot virtuele w^erelde op die Internet wat bewoon word deur spelers. Aangesien duisende spelers gelyktydig kan inskakel op die speletjie word daar verwag van die bediener en netwerk argitektuur om e ektief te skaleer om die groot hoeveelhede spelers te kan hanteer. Die traditionele kli ent/bediener model lei tot 'n groot nansi ele las vir die operateur van die bediener. Verskeie alternatiewe argitekture is al voorgestel om die tradisionele model te vervang, maar die aanvaarding en in gebruik neem van hierdie alternatiewe (soos eweknie-netwerke) is 'n stadige proses met sy eie stel uitdagings. Die voorgestelde hibriede stelsel is gebaseer op baie verskillende argitektuur- en eweknie konsepte wat in die literatuur oorweeg is. Die doel is om 'n kompromie vir bestaande komersieel suksesvolle MMASs te verskaf om eweknie komponente te implementeer sonder om die die bediener- of kli ent sagteware aan te pas. Met hierdie stelsel se ontwerp word die middelware sagteware ge mplementeer en gebruik in 'n regte, dog gekontroleerde omgewing, tesame met 'n Ultima Online bediener en sy kli ente. Die beweging speletjie meganisme word versprei onder die eweknie netwerk en die ander meganismes bly die verantwoordelikheid van die bediener. 'n Aantal eksperimente is ingespan om die e ek van die hibriede stelsel te meet op die oorspronklike kli ent/bediener stelsel, in terme van bandwydte, vertraging en impak op hardeware. Die resultate toon 'n toename van 35% in bediener-, 17% in slaaf-, en 3111% in supernodus bandwydte gebruik. Die vertraging van verspreide bediener meganismes neem af met tot 94%, terwyl onverspreide vertragings toeneem met tot 6000%. Hierdie resultate wys dat 'n stelsel wat geen aanpassing maak aan die bediener sagteware onwaarskynlik die gewenste voordele sal lewer. Deur egter 2 klein aanpassings toe te laat tot die bediener, is dit moontlik vir die hibriede stelsel om data las van die bediener en die speler se vertraging te verminder. Die bediener bandwydte kan met 39% verminder word, terwyl die supernodus bandwydte slegs met 1296% toeneem. Die verpreide vertragings handhaaf hul vermindering, terwyl die onverspreide vertragings onveranderd bly van die C/S stelsel.

Im Rahmen der Dissertation wurde ein Middlewaredienst entwickelt und realisiert. Es gestattet die dynamische Verwaltung heterogener Kontextquellen. Das zugrunde liegende Komponentenmodell selbstbeschreibender Context Provieder ermöglicht die lose Kopplung von Kontextquellen und -senken. Es wird durch Filter- und Konverterkomponenten zur generischen Providersselektion anhand domänenspezifischer Merkmale ergänzt. Die Kopplung der verteilten Dienstinstanzen erfolgt durch ein hybrides Peer-to-Peer-System. Dies trägt der Heterogenität der Endgeräte Rechnung, und erlaubt die skalierbare , verteilte Verwaltung von Kontextquellen in globalen Szenarien.

Im Rahmen der Dissertation wurde ein Middlewaredienst entwickelt und realisiert. Es gestattet die dynamische Verwaltung heterogener Kontextquellen. Das zugrunde liegende Komponentenmodell selbstbeschreibender Context Provieder ermöglicht die lose Kopplung von Kontextquellen und -senken. Es wird durch Filter- und Konverterkomponenten zur generischen Providersselektion anhand domänenspezifischer Merkmale ergänzt. Die Kopplung der verteilten Dienstinstanzen erfolgt durch ein hybrides Peer-to-Peer-System. Dies trägt der Heterogenität der Endgeräte Rechnung, und erlaubt die skalierbare , verteilte Verwaltung von Kontextquellen in globalen Szenarien.

L’évolution technologique du web durant ces dernières années a favorisé l’arrivée d’environnements virtuels collaboratifs pour la modélisation 3D à grande échelle. Alors que la collaboration réunit dans un même espace partagé des utilisateurs distants géographiquement pour un objectif de collaboration commun, les ressources matérielles qu'ils apportent (calcul, stockage, 3D ...) avec leurs connaissances sont encore trop rarement utilisées et cela constitue un défi. Il s'agit en effet de proposer un système simple, performant et transparent pour les utilisateurs afin de permettre une collaboration efficace à la fois sur le volet computationnel mais aussi, bien entendu, sur l'aspect métier lié à la modélisation 3D sur le web. Pour rendre efficace le passage à l’échelle, de nombreux systèmes utilisent une architecture réseau dite "hybride", combinant client serveur et pair-à-pair. La réplication optimiste s'adapte bien aux propriétés de ces environnements répartis : la dynamicité des utilisateurs et leur nombre, le type de donnée traitées (3D) et leur taille. Cette thèse présente un modèle pour les systèmes d’édition collaborative en 3D sur le web. L'architecture cliente (3DEvent) permet de déporter les aspects métiers de la 3D au plus près de l’utilisateur sous la forme d’évènements. Cette architecture orientée événements repose sur le constat d’un fort besoin de traçabilité et d’historique sur les données 3D lors de l’assemblage d’un modèle. Cet aspect est porté intrinsèquement par le patron de conception event-sourcing. Ce modèle est complété par la définition d’un intergiciel en pair-à-pair. Sur ce dernier point, nous proposons d'utiliser la technologie WebRTC qui présente une API familière aux développeurs de services en infonuagique. Une évaluation portant sur deux études utilisateur concernant l’acceptance du modèle proposé a été menée dans le cadre de tâches d’assemblage de modèles 3D sur plusieurs groupes d’utilisateurs
Web technologies evolutions during last decades fostered the development of collaborative virtual environments for 3D design at large scale. Despite the fact that collaborative environments gather in a same shared space geographically distant users in a common objective, the hardware ressources of their clients (calcul, storage, graphics ...) are often underused because of the challenge it represents. It is indeed a matter of offering an easy-to-use, efficient and transparent collaborative system to the user supporting both computationnal and 3D design visualisation and business logic needs in heterogeneous web environments. To scale well, numerous systems use a network architecture called "hybrid", combining both client-server and peer-to-peer. Optimistic replication is well adapted to distributed application such as 3D collaborative envionments : the dynamicity of users and their numbers, the 3D data type used and the large amount and size of it.This document presents a model for 3D web-based collaborative editing systems. This model integrates 3DEvent, an client-based architecture allowing us to bring 3D business logic closer to the user using events. Indeed, the need of traceability and history awareness is required during 3D design especially when several experts are involved during the process. This aspect is intrinsec to event-sourcing design pattern. This architecture is completed by a peer-to-peer middleware responsible for the synchronisation and the consistency of the system. To implement it, we propose to use the recent web standard API called WebRTC, close to cloud development services know by developers. To evaluate the model, two user studies were conducted on several group of users concerning its responsiveness and the acceptance by users in the frame of cooperative assembly tasks of 3D models

碩士
國立臺灣大學
資訊管理學研究所
93
In recent years, P2P (Peer-to-Peer) systems have drastically changed the way we share resources and gather information. Existing P2P systems can be roughly classified into four families-decentralized unstructured, decentralized structured systems, partial-centralized, and hybrid systems. The first three families have their own strengths and weaknesses. Therefore, hybrid systems tends to simultaneously adopt various approaches in other families to complement drawbacks of others. Some hybrid systems tend to concord features of unstructured and structured ones, such as flexibility, robustness, low maintenance and efficiency. However, existing hybrid systems adopt centralized mechanisms or pre-select powerful peers. In this paper we proposed Envoy, which organizes unstructured and structured P2P networks into a general-purpose hybrid P2P network without any kinds of centralized mechanism. To reinforce the structured overlay, only peers that meet several measures such as stability and bandwidth are eligible for serving on the overlay. Super-peers are automatically elected from the unstructured overlay and self-organized into the DHT overlay. Our self-organization mechanism ensures that elected peers are sufficient in number, stable and powerful enough. Through analysis and simulations, we prove that Envoy is scalable and low overhead even in the worst case.

Thesis (Ph. D.)--Florida State University, 2005.
Advisor: Dr. Gregory Riccardi, Florida State University, College of Arts and Sciences, Dept. of Computer Science. Title and description from dissertation home page (viewed June 7, 2005). Document formatted into pages; contains ix, 102 pages. Includes bibliographical references.

Indiana University-Purdue University Indianapolis (IUPUI)
Current supply chain information systems are transaction-based and suffer from lack of real-time transparency. Furthermore, they are often centralized and therefore cannot adequately scale to include a large number of small and medium size companies. This thesis presents a hybrid peer-to-peer supply chain physical distribution framework (HP3D) that addresses these increasingly critical gaps in a global market. HP3D leverages the advantages of hybrid networks through flexible peers and a light-weight index server in order to share supply chain physical distribution information in pseudo real-time among stakeholders. The architecture of HP3D consists of a hierarchy of dynamic sub-networks that evolve based on market demands and digitize the transfer of goods between suppliers and customers. These sub-networks are created on demand, emulate the end-to-end movement of the shipment and terminate when the delivery of goods is completed. A variation of blockchain technology is also proposed in order to increase the security level of the proposed framework.

博士
國立臺灣大學
資訊工程學研究所
90
Abstract In current Internet environment, various kinds of applications exist, for example, e-mail, WWW (World-Wide Web), FTP (File Transfer Protocol), streaming audio/video, and VoIP (voice over IP). However, each service has to be accessed with different application programs, and this makes service integration more difficult. Moreover, in client-server architecture widely deployed in these applications, server load is higher since extra processing is needed besides handling excessive client requests, for example, mail filtering or web content filtering. Most importantly, personalization settings for all kinds of services would further increase server load. Therefore, in this dissertation, a hybrid peer-to-peer architecture for Internet applications is proposed. With the deployment of location service, the current online status, device capabilities and latest location of a mobile node can be dynamically determined, for example, the current way of contact for users or the current IP address for resources. We can access a mobile node at any time with any device, and existing Internet applications can be improved by offloading the server. Moreover, personal configurations for each user and resource can be easily implemented for each service, thus achieving better customization for each individual user.

碩士
國立中山大學
資訊工程學系研究所
95
There are two main architectures in VOIP system at present. First is peer-to-peer, it has highly scalable, fault-tolerant and also can lighten the number and reliance of server. But there is no standard protocol between peers with different architecture, cause the clients unable to communication with each other. This problem can be solved by communicating from one P2P network to another. Second is Client-Server, it has mass of research data, lots of actual products, and standard protocol. This architecture is the most perfect one with simple structure, easy to maintain, lower response time than peer-to-peer structure, and has a variety of additional services, for instance Voice Mail, conference call, etc. All the client need is to obey sip standard protocol and it can register to any sip proxy to make a phone call. The disadvantage is no server no use. These two architectures have both good side and bad side, none of them is absolutely perfect. Our thesis is proposed a all new idea about “Hybrid”, this idea combine P2P and Client-Server architecture together to design a flexible soft phone that can be used is normal condition to register to a proxy, or setup a P2P network instantly in our own local area network. Finally our DCHS Mechanism is workable even when the sip proxy is maintaining or failure the client can use this mechanism to call any other user outside the P2P network by sharing other peers’ call history.

碩士
國立高雄應用科技大學
資訊管理系
97
Web Services becomes more important for cross-platform data transmission and exchange in recent years. In current standard of Web Service, all the facilities are build on traditional client-server model – a centralized framework. It often suffers from many problems such as performance bottleneck for single node failure and will cause systems work unstable. In the environment of Web Service, each service can be seen as a component, so how to make the service works stably is also a key issue. To address these problems, in this paper we discuss StarkWS infrastructure which constructs Web Services on P2P network, and offer the service register, query and invoke mechanism fit for P2P network. StarkWS also provide a series of service deploy, monitor and autonomous management mechanism for construct a stable Web Service environment.