Dissertations / Theses on the topic 'Quality of Service in SDN'
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1
Ongaro, Francesco. "Enhancing quality of service in software-defined networks." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/7356/.
Full textAbstract:
Resource management is of paramount importance in network scenarios and it is a long-standing and still open issue. Unfortunately, while technology and innovation continue to evolve, our network infrastructure system has been maintained almost in the same shape for decades and this phenomenon is known as “Internet ossification”.
Software-Defined Networking (SDN) is an emerging paradigm in computer networking that allows a logically centralized software program to control the behavior of an entire network. This is done by decoupling the network control logic from the underlying physical routers and switches that forward traffic to the selected destination. One mechanism that allows the control plane to communicate with the data plane is OpenFlow. The network operators could write high-level control programs that specify the behavior of an entire network.
Moreover, the centralized control makes it possible to define more specific and complex tasks that could involve many network functionalities, e.g., security, resource management and control, into a single framework.
Nowadays, the explosive growth of real time applications that require stringent Quality of Service (QoS) guarantees, brings the network programmers to design network protocols that deliver certain performance guarantees. This thesis exploits the use of SDN in conjunction with OpenFlow to manage differentiating network services with an high QoS. Initially, we define a QoS Management and Orchestration architecture that allows us to manage the network in a modular way. Then, we provide a seamless integration between the architecture and the standard SDN paradigm following the separation between the control and data planes.
This work is a first step towards the deployment of our proposal in the University of California, Los Angeles (UCLA) campus network with differentiating services and stringent QoS requirements. We also plan to exploit our solution to manage the handoff between different network technologies, e.g., Wi-Fi and WiMAX. Indeed, the model can be run with different parameters, depending on the communication protocol and can provide optimal results to be implemented on the campus network.
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Morin, Cédric. "Algorithms for implementing network services with a guaranteed quality of service in an SDN-NFV environment." Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2020. http://www.theses.fr/2020IMTA0198.
Full textAbstract:
Le trafic réseau ne cesse de croître et de nouveaux besoins font aujourd’hui leur apparition avec de très fortes contraintes en termes de ressources et de qualité de service. Pour y faire face la 5G propose une centralisation du contrôle et une abstraction des ressources basées sur SDN et NFV ce qui permet une automatisation du déploiement des services, une optimisation de l’usage des ressources et une réduction des coûts. SDN centralise le plan de contrôle du réseau et gère les ressources des liens tandis que NFV virtualise les ressources des nœuds et transforme les fonctions réseau en VNFs. Dans cette thèse, nous analysons et proposons de résoudre certaines difficultés que pose la mise en place de services réseau dans cet écosystème. Nous abordons d’abord la mise en place d’un service de connectivité à qualité de service garantie. Afin d’éviter un afflux de messages vers le contrôleur et un délai dans l’application de la politique d’accès nous transférons son exécution dans le plan de données. Nous proposons ensuite de rajouter des fonctions réseau à nos services. Nous formulons un algorithme de placement visant à épargner les ressources là où elles sont rares pour placer un maximum de services. Nous doublons cet algorithme d’une technique d’abstraction de la topologie du réseau afin de permettre aux entités tierces d’exposer et vendre leurs ressources sans divulguer les détails de leurs infrastructures. Enfin, pour permette à l’opérateur réseau d’acheter les ressources nécessaires à l’établissement de ses services pour un coût minimal nous proposons un algorithme d’optimisation des réservations basé sur les offres des opérateurs de datacenters ainsi que sur des prévisions de traficNetwork traffic keep growing and newneeds are emerging today with strong requirements in terms of resources and quality of service. To face them 5G relies on control plane centralization and abstraction of resources based on SDN and NFV which allow network services deployment automation, resources utilization optimization and cost reductions. SDN centralizes the network control plane and manages link resources while NFV virtualizes node resources and turns network functions into VNFs. In this thesis we analyze some of the difficulties raised by the establishment of a network service in this context and we propose solutions to solve them. We first tackle the setup of a connectivity service with guaranteed quality of service. To avoid a massive flow of monitoring information to the controller and a delay in the enforcement of the policy we transfer the policy’s execution to the data plane. Then our goal is to add network functions to our services. We design a placement algorithm that spare resources where they are scarce to save them for services that need them to place a maximum of services. We develop a topology abstraction technique to allow other tenants to expose and sell their resources without disclosing the details of their infrastructures. Finally, to help the network operator to buy the resources required to instantiate its network services at a minimal cost we propose an algorithm that optimizes resource reservations based on cloud operators’ commercial offers and network operator’s traffic predictions
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Alharbi, Faisal. "SDN-BASED MECHANISMS FOR PROVISIONING QUALITY OF SERVICE TO SELECTED NETWORK FLOWS." UKnowledge, 2018. https://uknowledge.uky.edu/cs_etds/72.
Full textAbstract:
Despite the huge success and adoption of computer networks in the recent decades, traditional network architecture falls short of some requirements by many applications. One particular shortcoming is the lack of convenient methods for providing quality of service (QoS) guarantee to various network applications. In this dissertation, we explore new Software-Defined Networking (SDN) mechanisms to provision QoS to targeted network flows. Our study contributes to providing QoS support to applications in three aspects. First, we explore using alternative routing paths for selected flows that have QoS requirements. Instead of using the default shortest path used by the current network routing protocols, we investigate using the SDN controller to install forwarding rules in switches that can achieve higher bandwidth. Second, we develop new mechanisms for guaranteeing the latency requirement by those applications depending on timely delivery of sensor data and control signals. The new mechanism pre-allocates higher priority queues in routers/switches and reserves these queues for control/sensor traffic. Third, we explore how to make the applications take advantage of the opportunity provided by SDN. In particular, we study new transmission mechanisms for big data transfer in the cloud computing environment. Instead of using a single TCP path to transfer data, we investigate how to let the application set up multiple TCP paths for the same application to achieve higher throughput. We evaluate these new mechanisms with experiments and compare them with existing approaches.
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Mouawad, Nadia. "SDN based Mobility Management and Quality of Service Provisioning for 5G Vehicular Networks." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASV003.
Full textAbstract:
Vehicle to Everything (V2X), y compris véhicule à véhicule (V2V) et véhicule à infrastructure (V2I), est la base de communications véhiculaires, où Les messages de sécurité routière active, d’infotainment et de gestion du trafic sont transmis sur des liaisons à bande passante élevée, à faible temps de latence et à haute fiabilité, ouvrant ainsi la voie à une conduite totalement autonome. L’objectif ultime des systèmes de communication V2X de la prochaine génération est de permettre une conduite coopérative sans accident. Pour atteindre cet objectif, le système de communication devra permettre un ensemble diversifié de cas d'usage, chacun avec un ensemble spécifique d'exigences. L'analyse des exigences relatives aux principales catégories de cas d’usage, en particulier les applications de temps réel critiques, souligne la nécessité d'une conception de système V2X efficace, capable de fournir les performances du réseau. La technologie de cinquième génération (5G), avec sa Qualité de Service (QoS) fournie en termes de capacité élevée et de faible temps de latence, est préconisée comme solution pour faire face aux exigences strictes imposées par les applications V2X.Dans cet écosystème 5G véhiculaire, diverses technologies de communication sont envisagés, allant des communications IEEE 802.11p, LTE, LTE-V aux Visible Light Communications. Par conséquent, l’hétérogénéité des technologies d’accès radio suscitera des inquiétudes quant à la gestion transparente de la mobilité et à la garantie de qualité de service.Cette thèse propose un nouveau système de gestion de la mobilité conçu pour les réseaux de véhicules 5G, basé sur la technologie émergente SDN (Software Defined Networking). SDN offre une programmabilité réseau qui vise à obtenir une allocation efficace des ressources du réseau et une gestion de la mobilité.Notre travail de recherche vise trois objectifs. Dans un premier temps, nous concevons une architecture de réseau de véhicules. Au sommet de cette architecture, nous implémentons deux Applications SDN, à savoir application de sélection de réseau et gestion de la mobilité Application. L'architecture proposée est renforcée par une solution de placement de contrôleur visant à réduire le temps de latence des communications. De plus, une préoccupation particulière est consacrée à la conception d’une application de sécurité active de la route SDN contrôlant l’emplacement des capteurs de vitesse sur les routes. L’application proposée vise à réduire le taux d’accidents, objectif principal du futur système de transport intelligent.Le deuxième objectif de cette thèse aborde le problème de la gestion de la mobilité.Ceci est réalisé en implémentant des applications liées à la mobilité SDN au sommet de la topologie de réseau adoptée. La première application est dédiée à la résolution du problème de sélection du réseau. Son objectif est de mapper les sessions V2X en cours sur la technologie correspondante. La deuxième application est conçue pour résoudre le handover; ceci est réalisé en utilisant la duplication de paquets et en introduisant un algorithme de routage efficace.Le troisième objectif de la thèse est axé sur l’approvisionnement en qualité de service pour les communications V2XVehicle to everything (V2X), including vehicle-to-vehicle (V2V) and vehicle-to-infrastructure(V2I), is the umbrella for the vehicular communication system, where active road safety, infotainment and traffic management messages are transmitted over high-bandwidth, low-latency, high-reliability links, paving the way to fully autonomous driving. The ultimate objective of next generation V2X communication systems is enabling accident-free cooperative driving that uses the available roadway efficiently. To achieve this goal, the communication system will need to enable a diverse set of use cases, each with a specific set of requirements.The main use case categories requirements analysis, specifically the critical realtime applications, points out the need for an efficient V2X system design that could fulfill the network performance. The Fifth Generation (5G) technology, with its provisioned QoS features in terms of high capacity and low latency, is advocated as a prominent solution to cope with the firm requirements imposed by V2X applications.In this multifaceted vehicular 5G ecosystem, diverse communication technologies are envisioned, spanning from IEEE 802.11p, LTE, LTE-V to vehicular visible light communications. Therefore, the heterogeneity of radio access technologies will raise a concern regarding the seamless mobility management and the quality of service guarantee.This thesis provides a novel mobility management scheme devised for 5G vehicular networks based on the emerging Software Defined Networking (SDN) technology.SDN provides network programmability that strives to achieve an efficient network resource allocation and mobility management.Our research work tackles three objectives. At a first stage, we design a software defined vehicular network topology. On the top of this topology, we implement twoSDN applications, namely Network Selection Application and Mobility Management Application. The proposed architecture is enhanced by a controller placement solution that aims at reducing communication latency. Moreover, a special concern is devoted to design a SDN road active safety application that controls speed traps placement. The proposed application aims at reducing accidents rate which is a main purpose of future Intelligent Transportation System.The second objective of this thesis tackles the mobility management problem. This is achieved by implementing SDN mobility related applications on the top of the adopted network topology. The first application is dedicated to solve the network selection problem; it aims at mapping running V2X sessions to the corresponding technology. The second application is conceived to solve the handover procedure; this is achieved using packets duplication and introducing an efficient routing algorithm.The third thesis objective is focused on QoS provisioning for V2X communications
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Кузнєцов, Ярослав Іванович. "Спосіб балансування навантаження в масштабних програмноконфігурованих мережах." Master's thesis, КПІ ім. Ігоря Сікорського, 2020. https://ela.kpi.ua/handle/123456789/34050.
Full textAbstract:
Робота складається із вступу, трьох розділів та одного додатку. Загальний
обсяг роботи: 69 аркуші основного тексту, 41 ілюстрація, 6 таблиць. При
підготовці використовувалася література з 38 різних джерел.
Актуальність. Дедалі більшу популярність набуває стрімінгові сервіси,
зростає кількість мережевих сервісів та абонентів мережі, що потребують
забезпечення якості обслуговування. Традиційні мережі наближаються до своєї
межі ефективності. Альтернативою традиційним мережам є централізована
архітектура SDN.
Ідея технології SDN не є новою, проте активне впровадження технології
припадає лише на останні 15 років. Однією із важливих задач при організації
мережі є задача балансування трафіку, що включає в собі маршрутизацію та
забезпечення якості обслуговування. Використання нової технології вимагає
розробки нових алгоритмів та протоколів, або адаптації традиційних, задача
балансування трафіку є актуальною.
Мета і завдання дослідження. Метою магістерської роботи є
розроблення методу, що дозволить маршрутизувати трафік по оптимальним
шляхам, уникаючи високої затримки та забезпечення більш рівномірного
завантаження мережі шляхом балансування трафіку, з використанням
можливостей програмно-конфігурованих мереж.
Для досягнення мети дослідження поставлено і вирішено такі завдання:
• дослідження структури та принципів побудови програмноконфігурованих мереж;
• дослідження методів масштабування програмно-конфігурованих
мереж;
• дослідження методів забезпечення якості обслуговування в
класичних та програмно-конфігурованих мережах;
• Дослідження методів маршрутизації в програмно-конфігурованих
мережах;
• Дослідження методів рішення задач багатокритеріальної
оптимізації;
• Pозробка методу балансування трафіку в програмно-конфігурованих мережах;
• Розробка програмного модулю на основі розробленого методу;
• Ілюстрація роботи моделі та аналіз отриманих результатів.
Об’єкт дослідження – процес пошуку оптимального шляху між вузлами
в програмно-конфігурованих мережах.
Предмет дослідження – методи маршрутизації та визначення оптимальності маршруту в програмно-конфігурованих мережах.
Методи досліджень. Для досягнення поставлених в магістерській роботі
задач, використано методи теорії графів, методи моделювання, методи
вирішення задач багатокритеріальної організації.
Проведене дослідження дає можливість використання розробленої моделі
в SDN мережах в якості застосунку контролера та виконувати емуляцію роботи
мережі для прогнозування трафіку та завантаженості компонентів мережі.
Особистий внесок здобувача. Магістерське дослідження є самостійно
виконаною роботою, в якій відображено особистий авторський підхід та
особисто отримані теоретичні та прикладні результати, що відносяться до
вирішення задачі маршрутизації та контролю трафіку в SDN мережах.
Формулювання мети та завдань дослідження проводилось спільно з науковим
керівником.
Практична цінність. Отримані результати можуть використовуватися у
майбутніх дослідженнях за напрямками:
• вдосконалення методів маршрутизації;
• аналіз та прогнозування трафіку в SDN;
• балансування навантаження в SDN мережах.Current work consists of receipt, three sections and one application. Total amount of work: 69 pages of the main text, 41 illustrations, 6 tables. By preparation a literature from 38 different sources was used. Topic Relevance. The increasing popularity acquires streaming services, the number of network services and subscribers of network grows that need ensuring quality of service. Traditional networks come nearer to the limit of efficiency. An alternative to traditional networks is the centralized architecture of SDN. The idea of SDN technology is not new, however active implementation of technology falls only on the last 15 years. The problem of balancing of traffic is one of important tasks at the organization of network that includes in itself routing and ensuring quality of service. Use of new technology demands development of new algorithms and protocols, or adaptation traditional, the problem of balancing of traffic is relevant. Research goal. The research goal of the master's thesis is development of a method that will allow to route traffic on optimal ways, avoiding a high delay and ensuring more uniform loading of network by balancing of traffic, with use of opportunities of software defined networks. For achievement of the goal of a research it is put and solved the following tasks: • Research of structure and the principles of construction software defined networks; • Researches of methods scaling software defined networks; • Researches of methods of ensuring quality of service in classical and software defined networks; • Researches of methods of routing in software defined networks; • Researches of methods of solving problems of multicriterial optimization; • Development of a method of balancing of traffic in software defined networks; • Development of the program module on the basis of the developed method; • Illustration of work of model and the analysis of the received results. Object of research – Process of search of an optimal way between nodes in software defined networks. Subject of research – Methods of routing and determination of optimality of a route in software defined networks. Methods of research. For achievement of the tasks set in the master's thesis, it is used methods of the theory of graphs, modeling methods, methods of the solution of tasks of the multicriteria organization. The conducted research gives the chance of use of the developed model in SDN networks as an application of the controller and to carry out emulation of network functioning for forecasting of traffic and load of components of network. Scientific contribution. The master research is independently done work in which it is reflected personal author's approach and personally received theoretical and applied results relating to the solution of a problem of routing and control of traffic in SDN networks. A formulation of the purpose and tasks the research was conducted together with the research supervisor. Practical value of obtained results. The received results can be used in future researches on the directions: • to improvement of methods of routing; • the analysis and forecasting of traffic in SDN; • balancing of loading in SDN networks.
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Toufga, Soufian. "Vers des réseaux véhiculaires (VANET) programmables grâce à la technologie SDN (software defined network)." Thesis, Toulouse 3, 2020. http://www.theses.fr/2020TOU30128.
Full textAbstract:
Le concept de réseau véhiculaire qui initialement prônait essentiellement des communications de véhicules à véhicules s'ouvre à d'autres types de communications impliquant véhicules et infrastructure (réseau), cloud ou piétons, etc. afin de pouvoir répondre aux besoins de la grande variété des nouvelles applications envisagées dans le cadre du Système de Transport Intelligent (ITS: Intelligent Transportation System). La multitude des technologies réseau d'accès, la très forte mobilité des véhicules et leur forte densité en milieu urbain ainsi que la prédominance des communications sans-fil en font un réseau hétérogène, avec des caractéristiques très dynamiques, dont certaines peu prévisibles, et sujet à des problèmes d'échelle. Face à ces difficultés, une piste envisagée par la communauté scientifique est d'appliquer le paradigme SDN (Software Defined Network) aux réseaux véhiculaires comme moyen pour, d'une part permettre l'hybridation et l'unification du contrôle des différentes technologies réseaux d'accès et, d'autre part, tirer partie de la vue centralisée du réseau et des données contextuelles venues du cloud pour développer des nouveaux algorithmes de contrôle pouvant potentiellement reposer sur la prédiction/estimation de l'état du réseau et donc anticiper certaines décisions de contrôle. C'est donc dans ce cadre que s'inscrit ce travail de thèse dont les contributions visent à développer le concept de réseaux véhiculaires définis par logiciel SDVN (Software Defined Vehicular Network). Quatre contributions y sont développées. La première précise l'architecture d'un réseau véhiculaire SDN hybride capable de répondre aux défis décrits ci-avant. Cette architecture est complémentée par une solution de placement des contrôleurs SDN. Nous proposons une approche dynamique capable d'ajuster le placement optimal des contrôleurs en fonction des changements de la topologie réseau dues aux fluctuations du trafic routier. Ce travail aborde également le problème de la vision globale du réseau qu'un contrôleur SDN peut se constituer, vision préalable et pierre angulaire à toute fonction de contrôle réseau. A ce problème, nous proposons des amendements et extensions au service de découverte de topologie "de fait" conçu pour les réseaux filaires pour l'adapter au contexte véhiculaire. En complément au service de découverte, nous proposons également un service d'estimation de topologie basé sur des techniques d'apprentissage automatique (Machine Learning) pour offrir aux fonctions de contrôle réseau une vision potentielle de l'état futur du réseau et donc les ouvrir à un contrôle proactif et intelligent du réseauThe vehicular network concept, which initially focused on vehicle-to-vehicle communication, is opening up to other types of communications involving vehicles and infrastructure (network), cloud or pedestrians, etc. to meet the needs of the wide variety of new applications envisaged in the framework of the Intelligent Transportation System (ITS). The multitude of network access technologies, the very high mobility of vehicles and their high density in urban areas, and the predominance of wireless communications make it a heterogeneous network, with very dynamic characteristics, some of which are difficult to predict, and subject to scalability problems. Given these issues, one direction, considered by the scientific community, is to apply the SDN (Software Defined Network) paradigm to vehicular networks as a means of, on the one hand, enabling the hybridization and unification of control of different network access technologies and, on the other hand, taking advantage of the centralized view of the network and contextual data from the cloud to develop new control algorithms that can potentially rely on the prediction/estimation of the network state and thus anticipate certain control decisions. Therefore, this thesis is part of this framework. Its contributions aim at developing the concept of SDVN (Software Defined Vehicular Network). Four contributions are developed. The first one specifies the architecture of a hybrid SDN vehicular network capable of meeting the challenges described above. This architecture is complemented by an SDN controller placement solution. We propose a dynamic approach capable of adjusting the optimal placement of controllers according to network topology changes due to road traffic fluctuations. This work also covers the problem of global network vision that an SDN controller can build up, which is a prerequisite and the cornerstone of any network control function. To this problem, we propose amendments and extensions to the "de facto" topology discovery service designed for wired networks to adapt it to the vehicular context. As a complement to the discovery service, we also propose a topology estimation service based on Machine Learning techniques to provide network control functions with a potential vision of the future state of the network and thus open them to proactive and intelligent network control
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Zaman, Faisal Ameen. "VN Embedding in SDN-based Metro Optical Network for Multimedia Services." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/35933.
Full textAbstract:
Currently a growing number of users depend on the Edge Cloud Computing Paradigm in a Metro Optical Network (MON). This has led to increased competition among the Cloud Service Providers (CPs) to supply incentives for the user through guaranteed Quality of Service (QoS). If the CP fails to guarantee the QoS for the accepted request, then the user will move to another CP. Making an informed decision dynamically in such a sensitive situation demands that the CP knows the user's application requirements. The Software Defined Networking (SDN) paradigm enabled the CP to achieve such desired requirement. Therefore, a framework called Virtual Network Embedding on SDN-based Metro Optical Network (VNE-MON) is proposed in this Thesis. The use of SDN paradigm in the framework guarantees profit to the CP as well as QoS to the user.\par
The design concept of the SDN control plane, raises concerns regarding its scalability, reliability and performance compared to a traditionally distributed network. To justify concerns regarding the SDN, the performance of VNE-MON and its possible dependancy on the controller location is investigated. Several strategies are proposed and formulated using Integer Linear Programming to determine the controller location in a MON. Performance results from the assessment of the VNE-MON illustrates that it is more stable compare to GMPLS-based network. It is evident that the controller location's attributes have a significant effect on the efficacy of the accepted VN request.
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Bendriss, Jaafar. "Cognitive management of SLA in software-based networks." Thesis, Evry, Institut national des télécommunications, 2018. http://www.theses.fr/2018TELE0003/document.
Full textAbstract:
L’objectif de la thèse est d’étudier la gestion de bout en bout des architectures à la SDN, et comment nos briques OSS (Operation Support System) doivent évoluer: cela implique d’étudier les processus métier associés, leurs implémentations ainsi que l’outillage nécessaire. Les objectifs de la thèse sont donc de répondre aux verrous suivants:1. Identifier les changements impliqués par l’émergence de ces réseaux programmables sur les architectures de gestions en termes d’exigences ou "requirements". L’étude peut être focalisée sur un type de réseau, mobile par exemple. 2. Identifier l’évolution à apporter aux interfaces de gestions actuelles: quelles alternatives aux FCAPS (fault, configuration, accounting, performance, and security) ? Quels changements à apporter aux couches de gestions allant du gestionnaire d’équipement ou "Element Management System" jusqu’au OSS ?The main goal of the PhD activities is to define and develop architecture and mechanisms to ensure consistency and continuity of the operations and behaviors in mixed physical/virtual environments, characterized by a high level of dynamicity, elasticity and heterogeneity by applying a cognitive approach to the architecture where applicable. The target is then to avoid the "build it first, manage it later" paradigm. The research questions targeted by the PhD are the following: 1. Identify the changes on Network Operation Support Systems implementation when using SDN as a design approach for future networks. The study could be restricted to mobile networks for example, or sub-part of it (CORE networks, RAN, data centers, etc); 2.Identify the needed evolution at the management interfaces level: a. Shall we need alternative to the well-known FCAPS and do we still need the element management system? b. What will change to provision an SDN based service? c. How to ensure resiliency of SDN based networks?
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Rodrigues, Tomás Marques. "End-user quality of service and experience in mobile networks." Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/23465.
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Mestrado em Engenharia de Computadores e TelemáticaMobile network operators use dedicated equipment (probes) to obtain performance, QoS and QoE metrics for their networks and services. This project aims to develop an Android application with probing features, not only complementing the dedicated equipment in the collection of information regarding performance, QoS and QoE, but also detecting problems in the network and its services automatically in mobile network commercial terminal and providing customer test tools and support for faster troubleshooting.
Os operadores de redes móveis recorrem a equipamentos dedicados (sondas) para obtenção de métricas relativas ao desempenho, QoS e QoE das suas redes e serviços. Pretende-se desenvolver uma aplicação Android com funcionalidades de sonda, não só complementando os equipamentos dedicados na recolha de informação relativa ao desempenho, QoS e QoE, como também detetando automaticamente problemas ao nível da rede e dos seus serviços no próprio terminal do cliente final, disponibilizando ferramentas de teste e suporte para uma resolução de problemas mais rápida e eficaz.
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Chang, Cybele T. Z. (Cybele Tsai Zin) 1973. "Improving jitney service quality : an appropriate governance model for San Juan, Puerto Rico." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/65063.
Full textAbstract:
Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2002.Includes bibliographical references (p. 154-160).
San Juan, Puerto Rico, like many North American cities, has turned to rail lines as a solution to the mounting traffic congestion threatening the urban environment. However, a rail system must rely on other transit modes to provide feeder services in order to expand its reach and broaden its customer base. This requires intermodal integration. The challenge facing the future success of Tren Urbano, the new rail system projected to open in the next two years, is the integration of the publicos. The publico is the owner operated jitney service indigenous to Puerto Rico that the government anticipates will offer crucial feeder services to Tren Urbano. For intermodal integration to succeed, publicos must offer comparable service quality. Unfortunately, the service quality of publico transit is poor as a consequence of the long-term decline of the publico industry. Therefore, the goal of the government is to improve publico service quality so it is comparable with the rest of the transit system, while recognizing the unique owner operator quality of the industry. This thesis examines four different jitney systems in North America. The study documents the development of the jitney service, how different cities govern jitney operators, and what affect the governance structure has on the quality of service. The purpose of this study is to determine what kind of governance structure leads to a high quality of jitney service. The study also examines what other factors contribute to high quality service. The ultimate goal is to apply the findings to San Juan, Puerto Rico in order to define future publico reforms. The case studies illustrate that North American jitney services all rely on hybrid governance models, consisting of government controls and self-regulating mechanisms. The study suggests that a hybrid governance structure that is based on cooperation between operators and government regulators leads to superior service quality. However, service quality is not merely a function of governance structure. Service quality also depends on the profitability of the jitney service, institutional strength, and the context of the industry. In a highly profitable setting, industry actors will spontaneously mobilize and provide a high quality of service. Consequently, the recommendations from this study examine ways of improving the profitability of the publico industry in order to improve the quality of service. In an unprofitable environment, the government must take the lead in developing other strategies to encourage service quality improvements. The recommendations in this study also suggests that the government proactively assist the publico industry improve service quality though various institutional and governance strategies.
by Cybele T.Z. Chang.
M.C.P.
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Buard, Karine. "L’évaluation et la qualité au service de l’école inclusive." Thesis, Paris 10, 2020. http://faraway.parisnanterre.fr/login?url=http://bdr.parisnanterre.fr/theses/intranet/2020/2020PA100012/2020PA100012.pdf.
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Le système éducatif français est désormais tenu de répondre à une triple exigence : 1) un paradigme de l’inclusion qui se substitue à celui de l’intégration, 2) une école de qualité pour tous qui constitue un surcroît d’exigence par rapport à l’objectif de réussite pour tous, 3) une redéfinition des responsabilités à chaque niveau du système. Dans ces conditions, les dispositifs pour élèves à besoins éducatifs particuliers (BEP) constituent un instrument privilégié au service d’une école inclusive et de qualité. Cette thèse se situe à l’échelle des établissements secondaires, à qui les responsables nationaux ont délégué de relever ce défi. Leurs acteurs doivent encore pour cela adapter leurs pratiques. Il s’agit d’interroger les leviers dont ils disposent pour répondre aux impératifs de qualité, d’inclusion et d’empowerment et d’envisager, face à ce faisceau d’exigences, l’inscription des établissements dans un processus d’amélioration continue de la qualité. La thèse, organisée en quatre articles, est construite autour d’une enquête sur les dispositifs proposés par des collèges publics aux élèves à haut potentiel intellectuel (HPI). Les trois premiers articles analysent différentes composantes de ces dispositifs pour élèves à BEP : l’appréciation des besoins des élèves à HPI par les principaux de collège pour le premier, l’accompagnement individuel de ces collégiens par un adulte dans le second, les facteurs à l’origine de leur satisfaction scolaire pour le troisième. Cette analyse conduit à produire un outil d’autoévaluation des établissements, i.e. un modèle d’évaluation de la qualité des dispositifs pour élèves à BEP qui est présenté dans le dernier articleThe French education system currently faces a triple requirement: 1) a paradigm of inclusion that replaces that of integration, 2) a school of quality for all that constitutes an additional requirement in relation to the objective of success for all, 3) a redefinition of responsibilities at each level of the system. Under these conditions, educational programs for students with special educational needs (SEN) are a key instrument for an inclusive and quality school. This PhD thesis deals with the secondary school level, which national responsibles have entrusted with taking up this challenge. To do this, their stakeholders still have to adapt their practices. The aim was to question the levers they can pull in order to meet the requirements of quality, inclusion and empowerment and to consider, in the light of this set of requirements, the involvement of institutions in a process of continuous quality improvement. The PhD thesis, organized into four articles, is based on a study of the educational programs offered by French public middle schools to gifted students. The first three articles analyze different components of these educational programs for students with SEN: first the assessment of the needs of gifted students by middle school headmasters, secondly the individual support of these middle school students by an adult in the second, and thirdly the factors behind their academic satisfaction. This analysis leads to the development of a self-assessment tool for schools, i.e. a model for evaluating the quality of educational programs for students with SEN, which is presented in the last article
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Colombo, Constant. "Élimination de l'impact de la résilience réseau dans un transport de flux vidéo par implémentation dans une architecture SDN contrainte par l'existant." Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0232.
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Dans les réseaux de distribution de contenu, la Qualité d'Expérience (QoE) est principalement évaluée par un indicateur de performance : la continuité de service. C'est pourquoi la robustesse des réseaux est une problématique majeure pour les opérateurs. La société TDF opère un réseau traditionnel de transport de flux audiovisuels en temps réel à l'aide de protocoles de multidiffusion. Toute panne réseau provoque cependant un temps de convergence non-nul, qui implique des pertes et des impacts sur le contenu. Ceci illustre que la continuité de service est une conséquence directe de la disponibilité de réseau. L'objectif des travaux de cette thèse est de définir une architecture pour inhiber les impacts sur le contenu lors des phases de cicatrisation du réseau. Cette architecture établit des paires d’arbres de multidiffusion redondants disjoints et dynamiques sur le réseau de transport. Les équipements de restitution pouvant exploiter cette redondance de chemins, il est possible de pallier à d'éventuelles pertes de paquet. L'essentiel des travaux porte sur le développement et l'évaluation de différents algorithmes de calcul des arbres de distribution destinés à alimenter le moteur de routage de l’architecture. La spécification des protocoles et processus de mise en œuvre sur le réseau est également abordée. L'implémentation de l'ensemble s'appuie sur une architecture de type Software Defined Networking (SDN), dans laquelle un contrôleur centralisé exploite la connaissance des performances et de la planification en bande passante pour établir et maintenir les paires d’arbres de multidiffusionIn Content Delivery Networks (CDN), Quality of Experience (QoE) provides a major performance indicator that is continuity of service. As a consequence, network robustness has become a major concern for network operators. TDF operates a traditional transport network for real-time video and audio transport through multicast. Any failure on the network causes a recovery time implying loss and an impact in the content viewing. This study's goal is to define an architecture preventing impact on the content during network healing time. This architecture computes and deploys redundant disjoint multicast trees on the transport network. As restitution equipments are able to exploit path diversity, packet loss consequences can be avoided. This work's main part is the development and evaluation of different algorithm for the computation of distribution trees, as part of the routing element of the architecture. Protocol specification and deployment process are also considered. Implementation is based on a Software Defined Networking (SDN) architecture in which a central controller uses its knowledge of the performance and bandwidth allocation to compute and maintain pairs of multicast trees
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Moussa, Sondes. "L'évaluation de la gestion de la réclamation et son impact sur la qualité relationnelle perçue par le consommateur. Cas du secteur touristique." Thesis, Lyon 3, 2011. http://www.theses.fr/2011LYO30101.
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Le secteur touristique souffre de plus en plus des départs de clients insatisfaits suite aux dysfonctionnements de services vécus. De nombreux établissements de services, attachent encore, peu d’importance à la gestion des réclamations en raison des moyens financiers qu’elles suscitent. Or, une gestion efficace de la réclamation pourrait transformer un client insatisfait en un client plus confiant et engagé. Notre recherche s’est intéressée à l’identification des critères d’évaluation sur lesquels les réclamants se basent pour juger la gestion de la réclamation, et à l’impact de cette évaluation sur la qualité de la relation établie avec l’établissement touristique. Pour ce faire une étude qualitative exploratoire suivie d’une étude quantitative ont été réalisées.Après avoir examiné la revue de la littérature, nous nous sommes focalisés sur les théories de la justice perçue lors de l’évaluation de la gestion de la réclamation. En outre, nous avons mobilisé les dimensions de la confiance et de l’engagement comme critères de jugement de la qualité relationnelle perçue. Les résultats de notre étude montrent l’existence d’un impact positif et significatif de quelques critères de la justice perçue (jugés par les réclamant comme étant les plus importants) sur la satisfaction post-réclamation et la qualité relationnelle perçue. Ces critères sont essentiellement l’équité du résultat accordé par l’établissement (ex : compensation accordée), l’empathie et la politesse développées par le personnel en contact, et la rapidité du traitement de la réclamationThe tourist sector is suffering more and more from the departure of the unsatisfied customers after experienced service failures. Several services companies, still attach, few importance to complaint handling because of financial funds needed. However, an efficient complaint handling management could transform a dissatisfied customer to a more confident and committed customer. Our research was interested in the identification of the appraisal criteria on which claimants base to judge complaint handling and the impact of this evaluation on the quality of the relationship established with the tourist establishment. Consequently, a qualitative study followed by a quantitative study has been accomplished. After examining the literature review, we focused on the perceived justice theory to evaluate the complaint handling. Besides, we used trust and commitment dimensions as a criteria of judgment of the perceived relationship quality (Morgan et Hunt, 1994).The outcomes of our study show the existence of a positive significant impact of some criteria of the perceived justice (considered by consumers as the most important), on recovery satisfaction and perceived relationship quality. These criteria are mainly equity of the result provided by the establishment (Ex. Compensation provided), empathy and politeness developed by the front line staff, and the quickness of the complaint treatment
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Rego, Máñez Albert. "Intelligent multimedia flow transmission through heterogeneous networks using cognitive software defined networks." Doctoral thesis, Universitat Politècnica de València, 2021. http://hdl.handle.net/10251/160483.
Full textAbstract:
[ES] La presente tesis aborda el problema del encaminamiento en las redes definidas
por software (SDN). Específicamente, aborda el problema del diseño de un protocolo
de encaminamiento basado en inteligencia artificial (AI) para garantizar
la calidad de servicio (QoS) en transmisiones multimedia. En la primera parte
del trabajo, el concepto de SDN es introducido. Su arquitectura, protocolos
y ventajas son comentados. A continuación, el estado del arte es presentado,
donde diversos trabajos acerca de QoS, encaminamiento, SDN y AI son detallados.
En el siguiente capítulo, el controlador SDN, el cual juega un papel central
en la arquitectura propuesta, es presentado. Se detalla el diseño del controlador
y se compara su rendimiento con otro controlador comúnmente utilizado.
Más tarde, se describe las propuestas de encaminamiento. Primero, se aborda
la modificación de un protocolo de encaminamiento tradicional. Esta modificación
tiene como objetivo adaptar el protocolo de encaminamiento tradicional
a las redes SDN, centrado en las transmisiones multimedia. A continuación,
la propuesta final es descrita. Sus mensajes, arquitectura y algoritmos son
mostrados. Referente a la AI, el capítulo 5 detalla el módulo de la arquitectura
que la implementa, junto con los métodos inteligentes usados en la propuesta
de encaminamiento. Además, el algoritmo inteligente de decisión de rutas
es descrito y la propuesta es comparada con el protocolo de encaminamiento
tradicional y con su adaptación a las redes SDN, mostrando un incremento de
la calidad final de la transmisión. Finalmente, se muestra y se describe algunas
aplicaciones basadas en la propuesta. Las aplicaciones son presentadas para
demostrar que la solución presentada en la tesis está diseñada para trabajar
en redes heterogéneas.[CA] La present tesi tracta el problema de l'encaminament en les xarxes definides per programari (SDN). Específicament, tracta el problema del disseny d'un protocol d'encaminament basat en intel·ligència artificial (AI) per a garantir la qualitat de servici (QoS) en les transmissions multimèdia. En la primera part del treball, s'introdueix les xarxes SDN. Es comenten la seva arquitectura, els protocols i els avantatges. A continuació, l'estat de l'art és presentat, on es detellen els diversos treballs al voltant de QoS, encaminament, SDN i AI. Al següent capítol, el controlador SDN, el qual juga un paper central a l'arquitectura proposta, és presentat. Es detalla el disseny del controlador i es compara el seu rendiment amb altre controlador utilitzat comunament. Més endavant, es descriuen les propostes d'encaminament. Primer, s'aborda la modificació d'un protocol d'encaminament tradicional. Aquesta modificació té com a objectiu adaptar el protocol d'encaminament tradicional a les xarxes SDN, centrat a les transmissions multimèdia. A continuació, la proposta final és descrita. Els seus missatges, arquitectura i algoritmes són mostrats. Pel que fa a l'AI, el capítol 5 detalla el mòdul de l'arquitectura que la implementa, junt amb els mètodes intel·ligents usats en la proposta d'encaminament. A més a més, l'algoritme intel·ligent de decisió de rutes és descrit i la proposta és comparada amb el protocol d'encaminament tradicional i amb la seva adaptació a les xarxes SDN, mostrant un increment de la qualitat final de la transmissió. Finalment, es mostra i es descriuen algunes aplicacions basades en la proposta. Les aplicacions són presentades per a demostrar que la solució presentada en la tesi és dissenyada per a treballar en xarxes heterogènies.
[EN] This thesis addresses the problem of routing in Software Defined Networks (SDN). Specifically, the problem of designing a routing protocol based on Artificial Intelligence (AI) for ensuring Quality of Service (QoS) in multimedia transmissions. In the first part of the work, SDN is introduced. Its architecture, protocols and advantages are discussed. Then, the state of the art is presented, where several works regarding QoS, routing, SDN and AI are detailed. In the next chapter, the SDN controller, which plays the central role in the proposed architecture, is presented. The design of the controller is detailed and its performance compared to another common controller. Later, the routing proposals are described. First, a modification of a traditional routing protocol is discussed. This modification intends to adapt a traditional routing protocol to SDN, focused on multimedia transmissions. Then, the final proposal is described. Its messages, architecture and algorithms are depicted. As regards AI, chapter 5 details the module of the architecture that implements it, along with all the intelligent methods used in the routing proposal. Furthermore, the intelligent route decision algorithm is described and the final proposal is compared to the traditional routing protocol and its adaptation to SDN, showing an increment of the end quality of the transmission. Finally, some applications based on the routing proposal are described. The applications are presented to demonstrate that the proposed solution can work with heterogeneous networks.
Rego Máñez, A. (2020). Intelligent multimedia flow transmission through heterogeneous networks using cognitive software defined networks [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/160483
TESIS
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Schnepf, Nicolas. "Orchestration et vérification de fonctions de sécurité pour des environnements intelligents." Thesis, Université de Lorraine, 2019. http://www.theses.fr/2019LORR0088/document.
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Les équipements intelligents, notamment les smartphones, sont la cible de nombreuses attaques de sécurité. Par ailleurs, la mise en œuvre de mécanismes de protection usuels est souvent inadaptée du fait de leurs ressources fortement contraintes. Dans ce contexte, nous proposons d'utiliser des chaînes de fonctions de sécurité qui sont composées de plusieurs services de sécurité, tels que des pare-feux ou des antivirus, automatiquement configurés et déployés dans le réseau. Cependant, ces chaînes sont connues pour être difficiles à valider. Cette difficulté est causée par la complexité de ces compositions qui impliquent des centaines, voire des milliers de règles de configuration. Dans cette thèse, nous proposons l'architecture d'un orchestrateur exploitant la programmabilité des réseaux pour automatiser la configuration et le déploiement de chaînes de fonctions de sécurité. Il est important que ces chaînes de sécurité soient correctes afin d’éviter l'introduction de failles de sécurité dans le réseau. Aussi, notre orchestrateur repose sur des méthodes automatiques de vérification et de synthèse, encore appelées méthodes formelles, pour assurer la correction des chaînes. Notre travail appréhende également l'optimisation du déploiement des chaînes dans le réseau, afin de préserver ses ressources et sa qualité de serviceSmart environments, in particular smartphones, are the target of multiple security attacks. Moreover, the deployment of traditional security mechanisms is often inadequate due to their highly constrained resources. In that context, we propose to use chains of security functions which are composed of several security services, such as firewalls or antivirus, automatically configured and deployed in the network. Chains of security functions are known as being error prone and hard to validate. This difficulty is caused by the complexity of these constructs that involve hundreds and even thousands of configuration rules. In this PhD thesis, we propose the architecture of an orchestrator, exploiting the programmability brought by software defined networking, for the automated configuration and deployment of chains of security functions. It is important to automatically insure that these security chains are correct, before their deployment in order to avoid the introduction of security breaches in the network. To do so, our orchestrator relies on methods of automated verification and synthesis, also known as formal methods, to ensure the correctness of the chains. Our work also consider the optimization of the deployment of chains of security functions in the network, in order to maintain its resources and quality of service
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Cabrera, Mario Alberto. "A measure of job satisfaction among child protective service workers in the County of San Bernardino: A comparative analysis of two district offices." CSUSB ScholarWorks, 1998. https://scholarworks.lib.csusb.edu/etd-project/1810.
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van, 't Hof David M. "Service Provisioning in SDN using a Legacy Network Management System." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-204957.
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Software Defined Networking (SDN) has become increasingly popular in combination with Network Function Virtualization (NFV). SDN is a way to make a network more programmable and dynamic. However, in order to create a homogeneous network using this concept, legacy equipment will have to be substituted by SDN equipment, which is costly. To close the gap between the legacy world and SDN, we introduce the concept of a legacy Network Management System (NMS) that is connected to an SDN controller to perform service provisioning. This way, the NMS is capable of configuring both legacy as well as SDN networks to provide customers with the services that they have ordered, while still allowing for new SDN features in the SDN domain of the network. The main service we wish to provide using SDN is Service Function Chaining (SFC). Service provisioning consists of dynamically constructing a path through the ordered network services, in this case Virtual Network Functions (VNFs). This thesis focuses on the SDN controller and its interaction with the NMS. This project aims at configuring OpenFlow rules in the network using an SDN controller to perform SFC. Moreover, the focus will be on how to represent an SDN element and a service function chain in the legacy network NMS. The thesis also contains a discussion on what information should be exchanged between the management software and the controller. The management software used is called BECS, a system developed by Packetfront Software. Integrating SDN in BECS is done by creating a proof of concept, containing a full environment from the low level network elements to the NMS. By using a bottom-up approach for creating this proof of concept, the information that BECS is required to send to the SDN controller can be identified before designing and implementing the connection between these two entities. When sending the information, the NMS should be able to receive acknowledgement of successful information exchange or an error. However, when the proof of concept was created a problem arose on how to test and troubleshoot it. For this reason, a web Graphical User Interface (GUI) was created. This GUI shows the number of packets that have gone through a VNF. Because it is possible to see how many packets go through a VNF, one can see where a network issue occurs. The subsequent analysis investigates the impact of making such a GUI available for a network administrator and finds that the part of the network where the configuration error occurs can be narrowed down significantly.Software Defined Networking (SDN) har blivit mer och mer populärt i kombination med Network Function Virtualization (NFV). SDN är en sätt för att göra ett nätverk mer programmerbart och dynamiskt. För att skapa ett homogent nätverk med detta koncept, behöver man dock ersätta traditionell utrustning med SDN utrustning som är dyr. För att stänga gapet mellan traditionella nätverk och SDN-världen, introducerar vi ett koncept med ett traditionell Network Management System (NMS) som är anslutet till en SDN-styrenhet för att utföra tjänsteprovisionering. På detta sätt kan NMS:et konfigurera både traditionella och SDN-nätverk, samt provisionera tjänster för kunderna medan nya SDN-funktioner möjliggörs i SDN-delen av nätverket. Den huvudsakliga tjänsten som vi vill lansera genom SDN är Service Function Chaining (SFC). Tjänsteprovisionering består av att konstruera en väg genom beställda tjänster, i detta fall Virtual Network Functions (VNFs). Detta examensarbete fokuserar huvusakligen på SDN-styrenheten och dess interaktion med NMS:et. Projektet syftar till att konfigurera OpenFlow regler i SDN-styrenheten för att utföra SFC. Dessutom fokuserar arbetet på hur man kan representera SDN-element och SFCs i ett traditionellt NMS. Vidare diskuteras vilken information som ska utbytas mellan NMS:et och SDNstyrenheten. NMS:et som ska vara användas är BECS, ett system utvecklat av Packetfront Software. Uppgiften löses genom att skapa ett proof of concept, som innehåller ett komplett system med alla komponenter från nätverkselement till NMS:et. Genom att använda en bottom-up-strategi för detta proof of concept kan informationen som BECS måste skicka till SDN styrenheten indentifieras, innan design och implementation av förbindelsen mellan enheterna kan utföras. När informationen är skickad ska NMS:et kunna hämta information om huruvida styrenheten fick informationen utan fel. Dock uppstår ett problem gällande hur man testar och felsöker detta proof of concept. Av denna anledning skapades ett web Graphical User Interface (GUI). Användargränssnittet visar antalet paket som går genom varje VNF, samt var i nätverket fel uppstår. Analysen undersöker hur stor effekten är för en nätverkadministrator och visar att området där fel kan uppstå begränsas avsevärt.
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Chen, Lunde. "Resource allocation in multi-domain wireless software-defined networks." Thesis, Toulouse, INSA, 2019. http://www.theses.fr/2019ISAT0002/document.
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La tendance à la numérisation de nombreux secteurs industriels tels que l’automobile, l’agriculture, les transports, la gestion urbaine, etc. révèle la nécessité de nouveaux usages des services de communication point-à-multipoint, tels que la fourniture massive de mises à jour logicielles et livraison fiable de messages d’alerte à la population, etc. D’un autre côté, la mise en logiciel des réseaux de nouvelle génération, avec notamment l’adoption croissante des réseaux définis par logiciel (SDN), apporte au réseau la flexibilité et les capacités de programmation permettant de prendre en charge des services de distribution point-à-multipoint de manière rentable. Cette thèse contribue au problème général de la fourniture de services de communication point-à-multipoint avec des exigences de qualité de service (QoS) dans un réseau SDN multi-domaines. Il considère également que certains des domaines sont des réseaux multi-sauts sans-fil. Tout d’abord, une technique d’agrégation de topologie de domaine basée sur une arborescence de Steiner, combinée à un algorithme heuristique d’allocation de ressources, sont proposés pour prendre en charge des services point-à-multipoint couvrant plusieurs domaines. Ensuite, un service de découverte de topologie générique est proposé pour les réseaux multi-sauts sans-fil basés sur le SDN afin de permettre au contrôleur SDN de créer et de gérer une vue complète du réseau avec divers attributs de nœud et de liaison sans-fil. Le contrôleur peut alors exposer des vues personnalisées aux applications de contrôle du réseau, telles que, par exemple, l’application en charge de la fourniture de services point-à-multipoint sur un réseau multi-sauts sans-fil basé sur le paradigme SDN. Un algorithme basé sur la programmation linéaire en nombres entiers et un algorithme génétique sont également proposés pour l’allocation de liens virtuels point-à-multipoint sur un réseau sans-fil multi-radio, multi-canaux et multi-sauts basé sur SDN. Enfin, pour traiter le cas des services dynamiques point-à-multipoint, nous proposons un schéma de réallocation de ressources qui répond aux exigences changeantes tout en réduisant les interuptions de serviceThe movement towards the digitalization of many industry sectors such as automotive, agriculture, transportation, city management, etc. is revealing the need for novel usages of point-to-multipoint network delivery services, such as massive delivery of software updates to objects, secure and reliable delivery of alert messages to population, etc. On another side, the softwarization of next generation networks, with amongst, the increasing adoption of Software Defined Networks (SDN) is bringing to the network the flexibility and programming capabilities that enable the support of point-to-multipoint delivery services in an efficient and cost-effective way. This PhD work contributes to the general problem of providing point-tomultipoint delivery services with Quality of Service (QoS) requirements in a multidomain SDN network. It also considers that some of the domains are wireless multi hop networks. First, a Steiner tree based network domain topology aggregation combined with a resource allocation heuristic algorithm is proposed to support point-to-multipoint delivery services that span multiple domains. Then, a generic topology discovery service is proposed for SDN based wireless multi-hop networks to let the SDN controller build and maintain a comprehensive view of the network with various node and wireless link attributes. From there, customized views can be exposed by the controller to network control applications, as, for instance, the application in charge of provisioning point-to-multipoint services on a SDN based wireless multi-hop network. An Integer linear programming based algorithm and a genetic algorithm are also proposed for the embedding of point-to-multipoint services on a SDN based multi-radio, multi-channel and multi-hop wireless network. Last, to address the case of dynamic point-to-multipoint services, we propose a resource reallocation scheme that meets the changing requirements while reducing service disruption
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Aravinthan, Gopalasingham. "SDN based service oriented control approach for future radio access networks." Thesis, Evry, Institut national des télécommunications, 2017. http://www.theses.fr/2017TELE0013.
Full textAbstract:
Le SDN (Software-Defined Networking) émerge comme une nouvelle architecture pour la programmation des réseaux. A l'origine, l'idée du SDN est de déplacer le plan de contrôle à l'extérieur des équipements, et de permettre ainsi un contrôle déporté de l'ensemble depuis une entité logicielle logique nommée "contrôleur". Le principal avantage d'une telle approche est de centraliser donc toute l'intelligence de gestion du réseau dans le contrôleur, qui s'appuie pour cela sur des protocoles standard et assure par ce biais la reprogrammation de la totalité de la partie du réseau sous son contrôle. L'évolution technologique vers le SDN est toujours en cours dans des scénarios de déploiement programmable et flexible des réseaux mobiles. Le NFV (Network Function Virtualization) est le processus de déplacement ou de migration des fonctions réseau d'un équipement dédié de réseau vers des serveurs génériques dans le Cloud. Les SDN et NFV sont deux technologies étroitement liées qui sont souvent utilisées ensemble. Le couplage fort entre les plans de contrôle et de données, ainsi que les limitations en matière de passage à l'échelle et de flexibilité, font que la virtualisation des réseaux mobiles actuels nécessite non seulement l'utilisation du Cloud Computing mais aussi les récentes innovations telles que SDN et NFV pour pouvoir permettre un déploiement à la demande des services réseaux (Network-as-a-Service) aux utilisateurs. Les lignes de recherche globales de cette thèse s'inscrivent dans deux principaux cas d'utilisation. Ces cas d'utilisation, bien qu'appelés de la "prochaine génération de réseaux mobiles", sont le "Telco" et le "Vertical", qui apparaissent ici couplés, les deux étant traditionnellement complètement séparés. Dans les cas d'utilisation de "télécommunications", nous exploitons les avantages de SDN pour avoir un cadre de contrôle flexible pour les réseaux d'auto-organisation (SON) et la division de traitement dynamique des utilisateurs. Dans le cas d'utilisation de "verticale", nous appliquons divers avantages du protocole SDN et OpenFlow pour utiliser efficacement les ressources radio du réseau de backhaul dans le système de communication train-sol. Notre cadre d'étude du SDN, en général, peut être une solution efficace et alternative pour la gestion RAN (Radio Access Network), c'est-à-dire pour des objectives comme l'optimisation des ressources radio, l'optimisation du réseau, la gestion de la mobilité et l'équilibrage de la charge, peuvent être atteint avec ce cadre. Grâce à l'analyse et l'expérimentation concrète des SDN et NFV pour le RAN, nous montrons que les solutions proposées dans ce travail peuvent apporter un faisceau d'avantages évidents aux réseaux mobiles tels que la flexibilité, la programmabilité, la gestion unifiée et la mise en œuvre de nouveaux servicesSoftware-Defined Networking (SDN) has emerged as a new intelligent architecture for network programmability. The primary idea behind SDN is to move the control-plane outside the switches and enable external control of data-plane through a logical software entity called controller. Such approach benefits mobile network management by brining complete intelligence to the logically centralized controller. Network Function Virtualization (NFV) is the process of relocating or migrating network functions from dedicated hardware to generic servers. SDN and NFV are two closely related technologies that are often used together. The traditional mobile network architecture due to its strongest coupling between control and data planes along with limitations in scalability and flexibility requires the usage of cloud computing along with the recent revolutionary approaches in networking such as SDN and NFV to have an architecture that deploys on demand "Network-as-a-Service" for users. The global research focus of this thesis falls in to two main use cases of next generation mobile networks such as Telco and Vertical. In the telco use cases, we exploit the advantages of SDN to have flexible control framework for both Self-Organizing Networks (SON) and dynamic user processing split. In vertical use case, we apply various advantages of SDN and OpenFlow protocol to efficiently utilize the scare radio resources of wireless backhaul network in the train-to-ground communication system. Our SDN framework in general can be an efficient and alternative solution for RAN management i.e. Radio Optimization, Network Optimization, Mobility Management and Load Balancing can be achieved with such framework. Through analysis and experimentation of SDN frameworks for RAN, we shows that the proposed solutions can bring set of advantages to wireless networks such as flexibility, programmability, unified management, and enables new services
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Herbaut, Nicolas. "Distribution de contenus collaborative basée sur une plateforme de fonctions réseaux virtualisées en tant que service." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0738/document.
Full textAbstract:
L’augmentation constante de la consommation de vidéos par des services par contournement(Over-The-Top) met à mal l’architecture actuelle d’Internet. Alors qu’une écrasante majorité de labande passante aujourd’hui est allouée à la livraison de contenus, les acteurs de l’Internet, tels queles fournisseurs de contenus, les réseaux de distribution de contenus et les fournisseurs d’accès sontobligés d’optimiser leurs réseaux pour supporter la qualité d’expérience attendue par l’utilisateurfinal. Ces réseaux couteux et spécialisés participent à l’ossification de l’Internet, rendant l’évolutionde son architecture plus difficile à moyen terme. En effet, un choix trop spécifique de dimensionnementdes liens et de la localisation des middle-boxes peut être un frein à une mise à jour ultérieureen vue du support de nouveaux cas d’utilisation. Heureusement, les technologies de virtualisationrécemment promues par les grands opérateurs Internet, les vendeurs de solutions et les organismesde standardisation, permettent une réelle programmabilité du réseau et une plus grande versatilitédans les usages de nouveaux équipements. En effet, l’agilité apportée par ces technologies permet ledéploiement de Fonctions Réseaux Virtuelles (VNF, Virtual Network Functions) pouvant s’exécutersur des serveurs de série à bas coût. Quant au Software-Defined Networking , il rend possible unegestion du réseau logiquement centralisée permettant la programmation des commutateurs.L’objectif de cette thèse est de montrer comment la distribution de contenu peut être amélioréecollaborativement à l’aide de la programmabilité de réseaux. Tout d’abord, nous proposons CDNaaS,une solution complète de réseau de livraison de contenu déployée sur une plateforme de "fonctionsréseaux en tant que service" adoptée et évaluée à large échelle dans le cadre du projet Européen FP7T-NOVA. Nous précisons les interfaces, l’architecture et les choix de conception fait pour développerla plateforme afin de fournir performance, auto-dimensionnement et réutilisabilité. Puis, nous proposonsdeux modèles de collaboration permettant aux acteurs de la livraison de contenu de travaillerensemble afin d’augmenter la qualité d’expérience pour l’utilisateur final, tout en promouvant unecompétition saine et une répartition équilibrée de la valeur ajoutée. Finalement, nous étudions lesdéfis liés à l’allocation de ressources virtuelles dans le cas d’un service vCDN, et proposons plusieursheuristiques et algorithmes permettant l’optimisation du coût du service.Cette thèse ouvre la voie à une distribution de contenu collaborative permettant aux utilisateursd’accéder à leurs contenus avec un haut standard de qualité, tout en contribuant à un développementsain de l’InternetThe constant rise of Over-The-Top video consumption nowadays challenges the current Internetarchitecture. As an overwhelming majority of the bandwidth today is dedicated to the deliveryof video contents, Internet actors such as Content Providers, Content Delivery Network, InternetService Providers are forced to optimize their networks to support the Quality of Experience expectedby the End-Users . Such costly specialized networks participate to the so-called "ossification" of theInternet whichmakes the architecture harder to update, as the placement and dimensioning of linksand middleboxes may be hard to change in the future to support new use cases. Fortunately, thetrend of Virtualizating and Softwarizing the networks pushed by major Telco operators, vendors andstandardization bodies has given hopes that the computing and networking infrastructure can beeasily re-purposed. The agility promoted by technologies such as Network Function Virtualizationand Software Defined Networking makes it possible for middleboxes to be deployed as VirtualNetwork Functions that can run on "commercial off-the-shelf" hardware while having the networkmanaged by a logically centralized controller deploying network configurations on programmableforwarding devices.The goal of this thesis is to show how content distribution can be collaboratively improved thanksto Network Softwarization. First, we propose CDN-as-a-Service (CDNaaS), a complete solution tovirtualize a Content Delivery Network on top of a VNF-as-a-Service platform, adopted and evaluatedat large scale in the FP7 T-Nova European project. We elaborate on the interfaces, architecture anddesign choices made to implement the platform to support performance, automatic scaling andre-usability. Then, we propose two collaboration models allowing the content delivery actors to workjointly on improving End-User Quality of experience while fostering a healthy competition and a fairbalance of revenue. Finally, we study the challenges of NFV resource allocation for the vCDN serviceand propose several heuristics and algorithms to optimize the proposed solution in a cost-effectiveway. This thesis paves the way towards a collaborative content distribution allowing End-Users toaccess their content with the highest standards while contributing to a sound development of theInternet
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Ekanayake, Mudiyanselage Wijaya Dheeshakthi. "An SDN-based Framework for QoSaware Mobile Cloud Computing." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/35117.
Full textAbstract:
In mobile cloud computing (MCC), rich mobile application data is processed at the cloud infrastructure by reliving resource limited mobile devices from computationally complex tasks. However, due to the ubiquitous and mobility nature, providing time critical rich applications over remote cloud infrastructure is a challenging task for mobile application service providers. Therefore, according to the literature, close proximity placement of cloud services has been identified as a way to achieve lower end-to-end access delay and thereby provide a higher quality of experience (QoE) for rich mobile application users. However, providing a higher Quality of Service (QoS) with mobility is still a challenge within close proximity clouds. Access delay to a closely placed cloud tends to be increased over time when users move away from the cloud. However, reactive resource relocation mechanism proposed in literature does not provide a comprehensive mechanism to guarantee the QoS and as well as to minimize service provisioning cost for mobile cloud service providers.
As a result, using the benefits of SDN and the data plane programmability with logically centralized controllers, a resource allocation framework was
proposed for IaaS mobile clouds with regional datacenters. The user mobility problem was analyzed within SDN-enabled wireless networks and addressed the possible service level agreement violations that could occur with inter-regional mobility. The proposed framework is composed of an optimization algorithm to provide seamless cloud service during user mobility. Further a service provisioning cost minimization criteria was considered during an event of resource allocation and inter-regional user mobility.
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Kayahan, Hüseyin. "Treatment Framework : Traffic Steering via Source-Routing in SDN for Service Function Chaining." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-247926.
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The middlebox architecture is long known for its inharmonious presence within the Internet architecture. Network functions realized in middleboxes are inclined to interpose end to end connections, modifying the datagram header or spawning new connections on behalf, which renders policy enforcement challenging. Moreover, their tight coupling with metadata makes its distributed persistence difficult, which hampers the flexible utilization and scalable provisioning of the middlebox infrastructure resources under varying loads. Existing attempts at mitigating these problems include middlebox placement, packet tagging and metadata migration; each solving only a part of the problem.Investing in the extensible nature of IPv6, the Treatment Framework (TRF) exploits source routing with the flavor of a discretionarily classifiable address space. Datagrams traverse the treatment domain with an extension header pushed and popped at the domain’s edges, for which forwarding takes place based on the information encoded within. The forwarding mechanics that leverage SDN consists of one match and three OpenFlow actions implementation, whereby TRF obviates the need for an underlying transport. Customizable address space allows providers to tailor routing aggregation to their middlebox farms topology, reducing the number of flow rules in the core to preinstallable sizes.Middleboxes in a treatment domain match traffic to the respective local policy based on the information encoded in the extension header. Extension headers are native to IPv6 and defined by standards, hence the middlebox modification problem is addressed without requiring alteration nor visibility into proprietary code. The framework resolves the policy enforcement problem altogether and allows asymmetric service chaining. While eliminating the flow setup time in the core, the framework’s footprint at ingress that push the extension header can get heavy with respect to flow churn rate.Det har länge varit känt att arkitektur baserad på mellanliggande utrustning, s.k.middlebox-arkitektur, inte alltid rimmar väl med Internet i övrigt. Nätverksfunktioner som implmenteras i middleboxar tenderar att leda till olika typer av förbindelser, modifierande av pakethuvuden eller nya uppkopplingar, vilket medför att det blir utmanande att verkställa olika typer av policy. Middlebox-lösningar är dessutom tätt kopplade till olika typer av metadata vilket innebär svårigheter för dess distribuerade fortlevnad och hindrar ett flexibelt utnyttjande och skalbar utbyggnad middleboxresurser under varierande trafiklast. Befintliga försök att mildra sådana problem inkluderar placering av mellanliggande utrustning, paketmärkning och migration av metadata; vart och ett av dessa löser endast delar av problemet.TRF (Treatment Framework) drar nytta av den utbyggbarhet som finns i IPv6 och använder vägval som styrs helt från avsändaren tillsammans med diskretionär adressrymd. IP-paketen traverserar en behandlings-domän och ett utökat pakethuvud används inom domänen. Det utökade pakethuvudet läggs till när paketet är på väg in i domänen och tas bort när paketet lämnar domänen. Inom domänen används information i det utökade pakethuvudet för att styra vidarebefordringen av paketet. Mekanismerna för vidarebefordring av paket använder sig av SDN och består av en match-operation och tre OpenFlow-åtgärder, varmed TRF kringgår behov av en underliggande transport. En anpass-ningsbart adressrymd gör det möjligt för leverantörer att skräddarsy vägvalsaggregering till sin middlebox-lösning, vilket gör att antalet trafikregler i kärnan av deras nät kan reduceras till förinställbara storlekar.En middlebox-lösning i en behandlings-domän matchar trafik mot respektive lokal policy baserad på information kodad i det utökade pakethuvudet. Tekniken med utökat pakethuvud är inbyggd i IPv6 och standardiserad vilket göra att paketmodifiering i en middlebox kan adresseras utan att kräva ändringar eller insyn i proprietär programvara. Ramverket löser problemet med verkställa olika typer av policy i sin helhet och medger skapandet av assymtriska kedjor av paketbehandlingstjänster. Tiden för att sätta upp paketflöden i kärnan av nätet kan elimineras, men det fotavtryck som ramverket ger i ingressdelen av domänen, där det utökade pakethuvudet skapas och läggs till inkommand paket, kan bli betydande med avseende på flödeshastigheten.
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Pattaranantakul, Montida. "Moving towards software-defined security in the era of NFV and SDN." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLL009/document.
Full textAbstract:
Ce travail de thèse, vise à explorer les problèmes de sécurité et les solutions, dans les environnements réseaux logiciels et virtualisés, avec les deux hypothèses suivantes:(1) Les changements de paradigmes introduits par les réseaux SDN et NFV permettent de développer de nouvelles approches en matière de gestion de la sécurité; (2) L’ensemble des menaces et vulnérabilités dans les environnements NFV/SDN doivent être intégralement pris en compte. Donc, dans une première partie, nous proposons une étude détaillée et complète, du point de vue de la sécurité, des architectures et protocoles SDN/NFV, mais aussi de la gestion et de l’orchestration des fonctions réseaux dans ces environnements (architecture MANO). Plusieurs cas d’usage sont spécifiés et proposés, en guise d’illustrations. Cette première étude a conduit à deux contributions majeures: (1) une architecture complète pour la gestion et l’orchestration de la sécurité (appelé SecMANO) basé sur NFV MANO. SecMANO permet de gérer un ensemble de fonctions service, de mécanismes de sécurité (contrôle d’accès, IDS/IPS, isolation, protection) basées sur un ensemble de règles; (2) une analyse complète des menaces et vulnérabilités dans le contexte NFV, à partir de cinq cas d'usage spécifiques, et des contre-mesures associées. Cette analyse a permis de proposer, une classification (taxonomie) complète et détaillée, des différents types de menace spécifique, associés à un ensemble de recommandations, pour une meilleure sécurité des services NFV. Nous estimons que ces deux premières contributions ouvrent des perspectives de recherche intéressantes, dans le domaine de la sécurité des réseaux NFV/SDN.Cette première étude, nous a amenés à proposer en guise de troisième contribution, une nouvelle architecture pour l’orchestration de fonctions de sécurité dans les environnements virtualisés. Cet orchestrateur de sécurité a été spécifié et développé comme un module d’extension pour les orchestrateurs existants. L’objectif est d’assurer un déploiement dynamique, flexible, à la demande, ainsi qu’une orchestration efficace des différents services de sécurité de base. Plus précisément, un mécanisme de contrôle d’accès, défini et appliqué à partir d’un langage de haut niveau, basé sur les piles "Tacker" (un service OpenStack pour orchestrateur NFV utilisant le modèle de donnés TOSCA), a été prototypé, implanté et testé. Ce prototype, permet de personnaliser et d’adapter dynamiquement, le modèle et la stratégie de contrôle d’accès, pour différents domaines utilisateurs concurrents. Ces domaines de sécurité indépendants, restent potentiellement protégés et isolés, dans les environnements à grande échelle, multi-opérateurs et multi-clouds. Le prototype et les expérimentations menées dans des conditions pratiques, montrent la faisabilité et l'efficacité de l’approche proposé.L’étude proposées dans la première partie, à partir d’une approche "cross-layer", mettent en évidence de nouveaux types de menaces et vulnérabilités et démontrent que dans ces environnements logiciels, virtualisés, la sécurité est l’élément critique. La quatrième contribution (SecSFC) vise à sécuriser et à fiabiliser, la composition et le chaînage de fonctions service (Service Function Chaining, SFC) dans les environnements NFV/SDN. SecSFC s’appuie sur un mécanisme de type "identity-based ordered multisignature" pour garantir les propriétés suivantes: (1) L’authentification de chaque fonction service, associée à une chaîne de fonctions service particulière; (2) La cohérence et le séquencement de l’ensemble des fonctions service associées à une composition ou à un chaînage particulier de fonctions service ("VNF forwarding graph"). L’analyse théorique du modèle proposé "SecSFC" et les résultats expérimentaux, montrent le caractère résilient de l’approche, en particulier face à un certain nombre d’attaques spécifiques (ex. modification des règles ou de la topologie) avec un temps de traitement et une latence, limitésThis thesis is intended to explore security issues in the virtualized and software-defined world, and starts with two important hypotheses: (1) SDN and NFV offer plenty of opportunities for us to rethink security management in the new networking paradigms; (2) both legacy and new security threats and vulnerabilities in NFV/SDN enabled environments need to be sufficiently addressed in order to pave the way for their further development and deployment. To validate the hypotheses, we carry out an in-depth study on NFV/SDN from security perspective, including its architecture, management and orchestration (MANO) framework, and use cases, leading to two major contributions, (1) a security management and orchestration framework (called SecMANO) based on NFV MANO, which has the potential to manage a set of policy-driven security mechanisms, such as access control, IDS/IPS, network isolation, data protection; (2) a comprehensive threat analysis on five NFV use cases and the state-of-the-art security countermeasures, resulting in a NFV layer-specific threat taxonomy and a set of security recommendations on securing NFV based services.We believe that both of the two contributions lay down a foundation for security research in NFV/SDN domain. In particular, based on the two contributions, we further develop a security orchestrator as an extension of available NFV orchestrator, with an objective to enabling the basic security functions to be effectively orchestrated and provided as on-demand services to the customers, meanwhile allowing high-level security policies to be specified and enforced in a dynamic and flexible way. Specifically, a software-defined access control paradigm is implemented and prototyped with OpenStack and Tacker (a NFV orchestrator using TOSCA model), which allows the security administrators to dynamically customize the access control models and policies for different tenant domains, eventually achieving flexible and scalable protection across different layers and multiple cloud data centers. Both prototype of concept and real-life experiments on testbed have been carried out, clearly demonstrating the feasibility and effectiveness of our security orchestrator.In addition, as our NFV cross-layer threat taxonomy indicates, a large set of novel threats will be introduced, among which VNF (Virtualized Network Function) is a unique and important asset that deserves careful protection. The fourth contribution of this thesis is therefore devoted to achieving secure and dependable SFC (Service Function Chaining) in NFV and SDN environment. Specifically, an identity-based ordered multisignature scheme called SecSFC is designed and applied to ensure that, (1) each service function involved in a particular service chain is authenticated and legitimate; (2) all the service functions are chained in a consistent, optimal, and reliable way, meeting with the pre-defined high-level specifications like VNF Forwarding Graph. Both theoretical security analysis and experimental results demonstrate that our scheme can effectively defend against a large set of destructive attacks like rule modification and topology tempering, moving an important step towards secure and dependable SFC. Importantly, the signature construction and validation process is lightweight, generating compact and constant-size keys and signatures, thereby only incurring minimal computational overhead and latency
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Efendic, Elvira, and Sabina Lajiq. "Service Quality : A research on how recruitment companies secure service quality." Thesis, Linnéuniversitetet, Ekonomihögskolan, ELNU, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-19422.
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Background: Service quality is considered to be a vital strategy for survival and success in today’s competitive environment. Although there have been an emphasis in quality overall, the research in companies performance within a business-to-business approach is still largely unexplored. Accordingly, service quality in recruitment companies will be interesting to examine in order to explore the business-to-business industry further. Purpose &: The purpose of this research is to study how recruitment Research Question: companies secure quality in their services. What factors indicate various quality levels? Methodology: This is a qualitative study with a deductive approach. Multiple case studies were conducted with a total of six respondents from three companies. Conclusion: This research concluded factors that indicate various quality levels in recruitment companies. The collected data that could not be strengthened with the theories was recommended as further research.
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FREITAS, MIGUEL DE ANDRADE. "QUALITY OF SERVICE ON INTERNET SERVICE PROVIDERS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2004. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=5031@1.
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O desenvolvimento de arquiteturas de Qualidade de Serviço
(QoS) para a Internet é um problema que tem recebido
bastante atenção ultimamente. Diversos motivos têm impedido
a implementação destas arquiteturas em larga escala como,
por exemplo, a dificuldade de estabelecimento de contratos
e políticas de QoS entre usuários, provedores e operadoras
e a ausência de mecanismos na rede para solicitar serviços
com garantia de qualidade. Apesar de não terem acesso a um
serviço que garanta certos níveis de desempenho para cada
tipo de aplicação, os usuários de Internet têm se mostrado
cada vez mais exigentes na qualidade do acesso à rede. Isto
se confirma com a migração crescente de muitos destes
usuários para o acesso à Internet em banda larga. Os
provedores de acesso à Internet, principalmente os de banda
larga, devem adotar políticas de gerenciamento de seus
recursos para atender às expectativas de qualidade dos
usuários e se manter competitivos no mercado. Neste
trabalho, foram identificados problemas nos processos
adotados em um provedor de acesso em banda larga sem fio, a
MLS Wireless. No sistema antigo, ocorriam situações que
causavam a indisponibilidade de serviços por causa da
limitação de conexões simultâneas na rede ou ainda uma
degradação na banda e aumento na latência do acesso devido
a falta de justiça no compartilhamento de recursos. O
trabalho sugere soluções para as deficiências encontradas,
implementando-as e analisando a eficácia das mesmas. Para
resolver o problema de indisponibilidade, sugere-se o
estabelecimento de limites por usuário, para que a
capacidade total do sistema não seja esgotada. Para
resolver o problema de injustiça e dar maior eqüidade na
distribuição de recursos entre os usuários, é implementado
um novo mecanismo de compartilhamento baseado em uma
disciplina de fila SFQ (Stochastic Fairness Queueing). Os
resultados mostraram que as modificações propostas foram
efetivas. O tempo de acesso à serviços de WWW e e-mail
durante períodos de congestionamento foi drasticamente
reduzido, em alguns casos, de cerca de 1 minuto para menos
de 10 segundos.The development of Quality of Service (QoS) architectures for the Internet is a problem that has received significative attention recently. The large scale deployment of such architectures has being blocked by several reasons, such as, the dificulty in establishing Service Level Agreements (SLA) of QoS policies between users, Internet Service Providers (ISP) and operators, and the lack of mechanisms on the network to request services with quality guarantees. Despite of not having access to a service that can guarantee certain levels of performance per aplication, the Internet users are getting more and more concerned about the network quality. That can be confirmed by the number of users that are migrating to the broadband Internet access. The ISP´s, specially the broadband ones, must take measurements to manage their resources to satisfy the users´ expectations of quality and stay competitive on the market. In this work, problems have being identified at the processes used by a broadband ISP, the MLS Wireless. With the old system, certain situations could cause the denial of service due the number of simultaneos connections or degradation and increased latency due the lack of fairness to share the network resources. This work suggests some solutions for these deficiencies, implementing and analyzing their effectiveness. To fix the denial of service, we suggest the limitation of resources per user, so that the total capacity won´t be depleted. To have the resources more fairly distributed among the users, a new mechanism of sharing is implemented, based on a discipline named SFQ (Stochastic Fairness Queueing). The results show that those modifications have being effective. The time to access services like WWW and e-mail during congestion periods was drasticaly reduced, in some cases, from about 1 minute to less than 10 seconds.
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Field, Daniel James. "Profit through product quality and quality service." Master's thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-02162010-020036/.
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Mahavier, Kendall Caitlin Alexandra. "Patterns in Road Maintenance: An Analysis of San Diego Roads." Oberlin College Honors Theses / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=oberlin1526393989343466.
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Castro, Marcel Cavalcanti de. "Propostas de implementação de qualidade de serviço na arquitetura VPN MPLS, utilizando linguagem de especificação formal SDL orientada a objetos e análise de desempenho utilizando o simulador OPNET." [s.n.], 2004. http://repositorio.unicamp.br/jspui/handle/REPOSIP/260377.
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Orientador: Walter da Cunha BorelliDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
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Resumo: Este trabalho apresenta propostas de implementação de qualidade de serviço na arquitetura VPN MPLS e analise de desempenho destas propostas. São desenvolvidos sistemas com base na arquitetura VPN MPLS e sugerido uma proposta de expansão da arquitetura VPN MPLS para mapeamento dinamico das prioridades dos clientes VPN na rede do provedor de serviço atraves da inserção do valor de prioridade de rota na tabela vrf e modificações realizadas no protocolo MP-BGP. As propostas foram especificadas utilizando a linguagem de especificação formal SDL orientada a objetos a partir da ferramenta SDL TAU Suite. Esta ferramenta permite simular os sistemas especificados, a partir de diagramas MSC, e validar estes sistemas para detecção e correção dos erros de logica e de especificação. A analise de desempenho das propostas foi realizada com o uso do simulador Opnet Modeler
Abstract: This work describe proposals for the implementation of quality of service (QoS) in VPN MPLS architecture, and their performance analysis based on simulations are presented. New systems are developed based on the VPN MPLS architecture, and it is being proposed an extension for the VPN MPLS architecture to construct a dynamic mapping of VPN clients priorities into service provider network through the insertion of priority field at vrf table and MP-BGP protocol modification. All these systems were specified using the SDL object-oriented formal language with the SDL TAU Suite tool (Telelogic, Sweden). This tool allows the simulation with MSC diagrams of the specified systems, and the validation of these systems by detecting and correcting logical and specification errors. The performance analysis of these proposals were realized through the Opnet Modeler simulator
Mestrado
Telecomunicações e Telemática
Mestre em Engenharia Elétrica
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Shrivastava, Rudraksh. "SDN-based flexible resource management and service-oriented virtualization for 5G mobile networks and beyond." Thesis, University of York, 2016. http://etheses.whiterose.ac.uk/17941/.
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This thesis examines how Software Defined Network (SDN) and Network Virtualization (NV) technologies can make 5G and beyond mobile networks more flexible, scalable and programmable to support the performance demands of the emerging heterogeneous applications. In this direction, concepts like mobile network slicing, multi-tenancy, and multi-connectivity have been investigated and their performance is analyzed. The SDN paradigm is used to enable flexible resource allocation to the end users, improve network resource utilization and avoid or rapidly solve the network congestion problems. The proposed network architectures are 3rd Generation Partnership Project (3GPP) standards compliant and integrate Open Network Foundation (ONF) SDN specifications to ensure seamless interoperability between different standards and backward/forward compatibility. Novel mechanisms and algorithms to efficiently manage the resources of evolving 5G Time-Division Duplex (TDD) networks in a flexible manner are introduced. These mechanisms enable formation of virtual cells on-demand which allows diverse resource utilization from multiple eNBs to the users. Within the scope of this thesis, SDN-based frameworks to enhance the QoE of end user applications considering Time Division-Long Term Evolution (TD-LTE) small cells have also been developed and network resource sharing scenarios with Frequency-Division Duplex (FDD)/TDD coexistence has been studied. In addition, this thesis also proposes and investigates a novel service-oriented network slicing concept for evolving 5G TDD networks which involve traffic prediction mechanisms and includes user mobility. An analytical model is also introduced that formulates the network slice resource allocation as a weighted optimization problem. The evaluations of the proposed solutions are performed using 3GPP standard compliant simulation settings. The proposed solutions have been compared with the state-of-the art schemes and the performance gains offered by the proposed solutions have been demonstrated. Performance is evaluated considering metrics such as throughput, delay, network resource utilization etc. The Mean Opinion Score (MOS) metric is used for evaluating the Quality of Experience (QoE) for end-user applications. With the help of SDN-based network management algorithms investigated in this work, it is shown how 5G+ networks can be managed efficiently, while at the same time provide enhanced flexibility and programmability to improve the performance of diverse applications and services delivered over the network to the end users.
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Rifai, Myriana. "Réseaux virtualisés de prochaine génération basés sur SDN." Thesis, Université Côte d'Azur (ComUE), 2017. http://www.theses.fr/2017AZUR4072/document.
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Les réseaux logiciels (Software Defined Network - SDN) permettent la programmation du réseau et facilitent sa configuration. Bien qu'SDN améliore les performances, il reste confronté à de multiples défis. Dans cette thèse, nous avons développé des solutions qui constituent un premier pas vers les réseaux SDN de prochaine génération. D’abord, nous présentons MINNIE qui permet la scalabilité des commutateurs SDN, qui ne supportent que quelques milliers de règles dans leur coûteuse mémoire TCAM. MINNIE comprime dynamiquement les règles de routage installées dans la TCAM, augmentant ainsi le nombre de règles pouvant être installées. Ensuite, nous abordons le problème de la dégradation de performance des flux courts avec un prototype d’ordonnancement qui exploite les statistiques des commutateurs pour diminuer leur délai de bout-en-bout. Puis, nous visons à diminuer l’intervalle de protection de 50ms qui n’est plus adapté aux applications modernes et réduit leur qualité d’expérience. Notre solution PRoPHYS s’appuie sur les statistiques des commutateurs dans les réseaux hybrides pour découvrir les pannes de liens plus vite que les solutions existantes. Enfin, nous abordons le problème de l’efficacité énergétique qui souvent mène à une dégradation de performance. Nous présentons SENAtoR, qui exploite les nœuds SDN en réseaux hybrides pour éteindre les nœuds réseau sans entraver la performance. Également, nous présentons SEaMLESS qui convertit le service fourni par une machine virtuelle inactive en une fonction de réseaux virtuelle pour permettre à l’administrateur d’utiliser les ressources bloquées tout en maintenant la disponibilité du serviceSoftware Defined Networking (SDN) was created to provide network programmability and ease complex configuration. Though SDN enhances network performance, it still faces multiple limitations. In this thesis, we build solutions that form a first step towards creating next-generation SDN based networks. In the first part, we present MINNIE to scale the number of rules of SDN switches far beyond the few thousands rules commonly available in TCAM memory, which permits to handle typical data center traffic at very fine grain. To do so MINNIE dynamically compresses the routing rules installed in the TCAM, increasing the number of rules that can be installed. In the second part, we tackle the degraded performance of short flows and present a coarse grained scheduling prototype that leverages SDN switch statistics to decrease their end-to-end delay. Then, we aim at decreasing the 50ms failure protection interval which is not adapted to current broadband speeds and can lead to degraded Quality of Experience. Our solution PRoPHYS leverages the switch statistics in hybrid networks to anticipate link failures by drastically decreasing the number of packets lost. Finally, we tackle the greening problem where often energy efficiency comes at the cost of performance degradation. We present SENAtoR, our solution that leverages SDN nodes in hybrid networks to turn off network devices without hindering the network performance. Finally, we present SEaMLESS that converts idle virtual machines into virtual network functions (VNF) to enable the administrator to further consolidate the data center by turning off more physical servers and reuse resources (e.g. RAM) that are otherwise monopolized
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Hollis, Charles. "Service quality evaluation in internal healthcare service chains." Queensland University of Technology, 2006. http://eprints.qut.edu.au/16267/.
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Measurement of quality is an important area within the services sector. To date, most attempts at measurement have focussed on how external clients perceive the quality of services provided by organisations. Although recognising that relationships between providers within a service environment are important, little research has been conducted into the identification and measurement of internal service quality. This research focuses on the measurement of internal service quality dimensions in the complex service environment of an internal healthcare service chain.
The concept of quality in healthcare continues to develop as various provider, patient and client, governmental, and insurance groups maintain an interest in how to 'improve' the quality of healthcare service management and delivery. This research is based in healthcare as a major area within the service sector. The service environment in a large hospital is complex, with multiple interactions occurring internally; health is a significant field of study from both technical and organisational perspectives providing specific prior research that may be used as a basis for, and extension into service quality; and the implications of not getting service delivery right in healthcare in terms of costs to patients, families, community, and the government are significant.
There has been considerable debate into the nature, dimensionality, and measurement of service quality. The five dimensions of SERVQUAL (tangibles, assurance, reliability, responsiveness, and empathy) have become a standard for evaluations of service quality in external service encounters, although these have been challenged in the literature. As interest in internal service quality has grown, a number of researchers have suggested that external service quality dimensions apply to internal service quality value chains irrespective of industry. However, this transferability has not been proven empirically.
This research examines the nature of service quality dimensions in an internal healthcare service network, how these dimensions differ from those used in external service quality evaluations, and how different groups within the internal service network evaluate service quality, using both qualitative and quantitative research. Two studies were undertaken. In the first of these, interviews with staff from four groups within an internal service chain were conducted. Using dimensions established through qualitative analysis of this data, Study Two then tested these dimensions through data collected in a survey of staff in a major hospital.
This research confirms the hierarchical, multidirectional, and multidimensional nature of internal service quality. The direct transferability of external quality dimensions to internal service quality evaluations is only partially supported. Although dimension labels are similar to those used in external studies of service quality, the cross-dimensional nature of a number of these attributes and their interrelationships needs to be considered before adopting external dimensions to measure internal service quality. Unlike in previous studies, equity has also been identified as an important factor in internal service quality evaluations.
Differences in service expectations between groups in the internal service chain, and differentiation of perceptions of dimensions used to evaluate others from those perceived used in evaluations by others were found. This has implications on formulation of future internal service quality instruments. For example, the expectations model of service quality is currently the dominant approach to conceptualising and developing service quality instruments. This study identifies a number of problems in developing instruments that consider differences in expectations between internal groups. Difficulty in evaluating the technical quality of services provided in internal service chains is also confirmed.
The triadic nature of internal service quality evaluations in internal healthcare service chains and the problems associated with transferring the traditional dyadic measures of service quality are identified. The relationships amongst internal service workers and patients form these triads, with patient outcomes a significant factor in determining overall internal service quality, independent of technical quality.
This thesis assists in supporting the development of measurement tools more suited to internal service chains, and will provide a stronger and clearer focus on overall determinants of internal service quality, with resultant managerial implications for managerial effectiveness.
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Al-Ali, Rashid J. "Quality of service management in service-oriented grids." Thesis, Cardiff University, 2005. http://orca.cf.ac.uk/55995/.
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Grid computing provides a robust paradigm for aggregating disparate resources in a secure and controlled environment. The emerging grid infrastructure gives rise to a class of scientific applications and services in support of collaborative and distributed resource-sharing requirements, as part of teleimmersion, visualization and simulation services. Because such applications operate in a collaborative mode, data must be stored, processed and delivered in a timely manner. Such classes of applications have collaborative and distributed resource-sharing requirements, and have stringent real-time constraints and quality-of-service (QoS) requirements. A QoS management approach is therefore essential to orchestrate and guarantee the interaction among such applications in a distributed computing environment. Grid architectures require an underpinning of QoS support to manage complex computation-intensive and data-intensive applications, as current grid middleware solutions lack QoS provision. QoS guarantees in the grid context have, however, not been given the importance they merit. To enhance its functionality, a computational grid must be overlaid with an advanced QoS architecture to best execute those applications with real-time constraints. This thesis reports on the design and implementation of a software framework, called Grid QoS Management (G-QoSm). G-QoSm incorporates a new QoS management model and provides a service-oriented QoS management approach that supports the Open Grid Service Architecture. Its novel features include grid-service discovery based on QoS attributes, immediate and advance resource reservation, service execution with QoS constraints, and techniques for QoS adaptation to compensate for resource degradation, and to optimise resource allocation while maintaining a service level agreement. The benefits of G-QoSm are demonstrated by prototype test-beds that integrate scientific grid applications and simulate grid data-transfer applications. Results show that the grid application and the data-transfer simulation have better performance when used with the proposed QoS approach. QoS abstractions are presented for building QoS-aware applications, in the context of service-oriented grids. These abstractions are application programming interfaces to facilitate application developers utilising the proposed QoS management solution.
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Tomassilli, Andrea. "Vers les réseaux de nouvelle génération avec SDN et NFV." Thesis, Université Côte d'Azur (ComUE), 2019. http://www.theses.fr/2019AZUR4044.
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Les progrès récents dans le domaine des réseaux, tels que les réseaux logiciel (SDN) et la virtualisation des fonctions réseaux (NFV), modifient la façon dont les opérateurs de réseaux déploient et gèrent les services Internet. D'une part, SDN introduit un contrôleur logiquement centralisé avec une vue globale de l'état du réseau. D'autre part, NFV permet le découplage complet des fonctions réseaux des appareils propriétaires et les exécute en tant qu'applications logicielles sur des serveurs génériques. De cette façon, les opérateurs de réseaux peuvent déployer dynamiquement des fonctions réseaux virtuelles (VNF). SDN et NFV, tous deux séparément, offrent aux opérateurs de nouvelles opportunités pour réduire les coûts, améliorer la flexibilité et le passage à l'échelle des réseaux et réduire les délais de mise sur le marché des nouveaux services et applications. De plus, le modèle de routage centralisé du SDN, associé à la possibilité d'instancier les VNF à la demande, peut ouvrir la voie à une gestion encore plus efficace des ressources réseaux. Par exemple, un réseau SDN/NFV peut simplifier le déploiement des chaînes de fonctions de services (SFC) en rendant le processus plus facile et moins coûteux. Dans cette thèse, notre objectif était d'examiner comment tirer parti des avantages potentiels de combiner SDN et NFV. En particulier, nous avons étudié les nouvelles possibilités offertes en matière de conception de réseau, de résilience et d'économies d'énergie, ainsi que les nouveaux problèmes qui surgissent dans ce nouveau contexte, comme l'emplacement optimal des fonctions réseaux. Nous montrons qu'une symbiose entre le SDN et le NFV peut améliorer la performance des réseaux et réduire considérablement les dépenses d'investissement (CapEx) et les dépenses opérationnelles (OpEx) du réseauRecent advances in networks, such as Software Defined Networking (SDN) and Network Function Virtualization (NFV), are changing the way network operators deploy and manage Internet services. On one hand, SDN introduces a logically centralized controller with a global view of the network state. On the other hand, NFV enables the complete decoupling of network functions from proprietary appliances and runs them as software applications on general–purpose servers. In such a way, network operators can dynamically deploy Virtual Network Functions (VNFs). SDN and NFV benefit network operators by providing new opportunities for reducing costs, enhancing network flexibility and scalability, and shortening the time-to-market of new applications and services. Moreover, the centralized routing model of SDN jointly with the possibility of instantiating VNFs on–demand, may open the way for an even more efficient operation and resource management of networks. For instance, an SDN/NFV-enabled network may simplify the Service Function Chain (SFC) deployment and provisioning by making the process easier and cheaper. In this study, we aim at investigating how to leverage both SDN and NFV in order to exploit their potential benefits. We took steps to address the new opportunities offered in terms of network design, network resilience, and energy savings, and the new problems that arise in this new context, such as the optimal network function placement in the network. We show that a symbiosis between SDN and NFV can improve network performance and significantly reduce the network's Capital Expenditure (CapEx) and Operational Expenditure (OpEx)
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Southard, Robyn Nicole. "Employee engagement and service quality." Pullman, Wash. : Washington State University, 2010. http://www.dissertations.wsu.edu/Thesis/Spring2010/R_Southard_042010.pdf.
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Thesis (Master of Public Affairs)--Washington State University, May 2010.Title from PDF title page (viewed on July 13, 2010). "Department of Political Science." Includes bibliographical references (p. 28-31).
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Campbell, Andrew T. "A quality of service architecture." Thesis, Lancaster University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337575.
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Ingram, D. "Integrated quality of service management." Thesis, University of Cambridge, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604934.
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Much work has been done on real time scheduling algorithms, but prototypes have made assumptions preventing their adoption in production desktop systems. In particular, they are generally incompatible with common monolithic kernel design and ubiquitous client-server architectures. Acceptance has also been poor because little attention is given to automatically managing quality of service parameters. This dissertation explores the use of soft real time scheduling on a conventionally structured platform. The approach taken is to extend an existing system, thus preserving a large, realistic application software base. The modified system is called Linux-SRT. Results show that soft real time scheduling is effective even on desktop systems which lack fine-grained preemptivity and response times. A basic design premise is that scheduling is separated from functionality, and this allows quality of service to be associated with any unmodified Linux application. End to end quality of service is viewed as a middleware service. Servers and IPC: Our solution makes important servers aware of their clients' Quality of Service, without needing to restructure them. Real time multi-threaded servers are supported with reserves allocated to sets of threads. Single-threaded servers such as the X window system are also addressed with a retrospective accounting mechanism. An asynchronous kernel events system ties the components together and allows servers to synchronise with other activities. Sockets between resource controlled processes provide integral peer authentication for admission control and priority inheritance. Quality of Service Management: Quality of service parameters are applied automatically to real time applications. The user may override this, but care has been taken to streamline the interface. Control and status indicators are tightly integrated with window management functions, hence avoiding cumbersome control programs.
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Chan, Yan-sum Danny, and 陳仁深. "Quality service in Hongkong post." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1998. http://hub.hku.hk/bib/B31268602.
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Chan, Yan-sum Danny. "Quality service in Hongkong post /." Hong Kong : University of Hong Kong, 1998. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19876713.
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Chen, Po-Wei, and 陳柏瑋. "An SDN-Based Quality Aware Routing Mechanism for Various Service." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/555jk9.
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碩士淡江大學
電機工程學系碩士班
105
Best-effort delivery mechanism is no longer fulfilling the needs of growing internet requirements, Internet Engineering Task Force (IETF) therefore announced Quality of Service (QoS) to relieve the intense network. However, those two service insurance methods (IntServ, Diffserv) of QoS are still basing on conventional hop-by-hop routing, which requires massive facilities to fulfill rush hours, but mostly idling on off-peak time. Besides, those improvements cannot specifically match every kind of internet services by various conditions, such as bandwidth, delay and jitter. According to experiments, we know that Streaming services need sufficient bandwidth、low delay、low jitter and low loss rate; Voice services need low delay、low jitter，but Voice service does not need much bandwidth, if it has a dejitter buffer, it can reduce the jitter, but increase the delay; Gaming services need low delay and low jitter, but jitter is the most serious impact on the game experience; data transmission services just need sufficient bandwidth. The developing SDN is therefore presenting to solve this issue effectively. Under the OpenFlow standard, SDN is a novel networking structure, which is considering as highly efficient, adaptive, and easy to be altered and managed. SDN contains control layer and transmission layer, transmissions are handled by switch and the controller processes the rest of the control progresses, and OpenFlow standard is used for communications between controllers and network devices. Centralized controller management can therefore achieve an effective software control. Sensing the connecting status of switches further to provide efficient routing control i.e. transmitting packages by the best path in the network topology. Among various routing algorithms, Dijkstra’s Shortest Path Algorithm is considering as a simple but very efficient algorithm. This algorithm calculates routing weight from nodes to nodes to build best routing tree and to acquire the routing result quickly. This work makes a combination of all those conditions and conceptions above, creates alternative routing mechanisms to process different networking services. And by Dijkstra’s Shortest Path Algorithm to calculate proper routing, this work would be therefore achieve the multi-services quality insurance control based on SDN.
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Andersson, Emma, and Johan Bröhne. "High Quality of Service in SDN : Bandwidth gurantee with QoS." Thesis, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-35083.
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Video streaming through IP networks has risen rapidly over the recent years, and will continue to do so over the coming years. In addition to this, new technologies such as Virtual Reality and robotics will lead to many new applications that will put high pressure on the networks. To combat these challenges, networks need to be application sensitive, and be able to provide Quality of Service (QoS) based on requirement. Network paradigms like Software Defined Networking (SDN) enables the network to be directly programmable, and could thus solve the challenge. In this thesis, the objective is to research if SDN can provide High QoS. Methods are developed to achieve High QoS with SDN. A combination of Differentiated Services Code Point (DSCP) values and DSCP remarking with Meters are used enable High QoS and together they can give bandwidth guarantee. As a result of the thesis, a solid theoretical method is provided for achieving QoS, tests are performed and show that QoS can be implemented in SDN, but it is unable to implement High QoS due to the lack of implementation for Meters with DSCP remarking.
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Owens, II Harold. "Provisioning end-to-end quality of service for real-time interactive video over software-defined networking." Thesis, 2016. https://doi.org/10.7912/C2WW74.
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Indiana University-Purdue University Indianapolis (IUPUI)This thesis contains four interrelated research areas. Before presenting the four research areas, this thesis presents literature review on Software-Defined Networking (SDN), a network architecture that allows network operator to manage the network using high level abstractions. This thesis presents taxonomy for classifying SDN research. In research first area, this thesis presents Video over Software-Defined Networking (VSDN), a network architecture that selects feasible paths using the network-wide view. This thesis describes the VSDN protocol which is used for requesting service from the network. This thesis presents the results of implementing VSDN prototype and evaluates behavior of VSDN. Requesting service from the network requires developer to provide three input parameters to application programmable interface. The message complexity of VSDN is linear. In research second area, this thesis presents Explicit Routing in Software-Defined Networking (ERSDN), a routing scheme that selects transit routers at the edge of network. This thesis presents the design and implementation of ERSDN. This thesis evaluates the effect of ERSDN on the scalability of controller by measuring the control plane network events-packets. ERSDN reduces the network events in the control plane by 430%. In research third area, this thesis presents Reliable Video over Software-Defined Networking (RVSDN) which builds upon previous work of Video over Software-Defined Networking (VSDN) to address the issue of finding most reliable path. This thesis presents the design and implementation of RVSDN. This thesis presents the experience of integrating RVSDN into ns-3, a network simulator which research community uses to simulate and model computer networks. This thesis presents RVSDN results and analyzes the results. RVSDN services 31 times more requests than VSDN and Multiprotocol Label Switching (MPLS) explicit routing when the reliability constraint is 0.995 or greater. In research fourth area, this thesis presents Multi-Domain Video over Software-Defined Networking (MDVSDN), a network architecture that selects end-to-end network path or path for real-time interactive video applications across independent network domains. This thesis describes the architectural elements of MDVSDN. This thesis presents the results of implementing a prototype of MDVSDN and evaluates the behavior of MDVSDN. The message complexity of MDVSDN is linear. The contribution of this thesis lays the foundation for developing a network architecture that improves the performance of real-time interactive video applications by selecting feasible end-to-end multi-domain path among multiple paths using bandwidth, delay, jitter, and reliability.
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AlZailaa, Alaa Rashed. "Enhanced video transmission using SDN in cloud-based environment." Master's thesis, 2019. http://hdl.handle.net/10773/29663.
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The great technological development of informatics has opened the way for
provisioning various services and new online-based entertainment services,
which have expanded significantly after the increase in social media applications
and the number of users. This significant expansion has posed an additional
challenge to Internet Service Providers (ISP)s in terms of management
for network, equipment and the efficiency of service delivery. New notions and
techniques have been developed to offer innovative solutions such as SDN for
network management, virtualization for optimal resource utilization and others
like cloud computing and network function virtualization. This dissertation
aims to manage live video streaming in the network automatically by adding a
design architecture to the virtual network environment that helps to filter video
packets from the remaining ones into a certain tunnel and this tunnel will be
handled as a higher priority to be able to provide better service for customers.
With the dedicated architecture, side by side, a monitoring application integrated
into the system was used to detect the video packets and notify the
SDN server to the existence of the video through the networkOs grandes avanços tecnológicos em informática abriram o caminho para o fornecimento de vários serviços e novos aplicações de entretenimento baseadas na web, que expandiram significativamente com a explosão no número de aplicações e utilizadores das redes sociais. Esta expansão significativa colocou desafios adicionais aos fornecedores de serviços de rede, em termos de gestão de rede, equipamento e a eficácia do fornecimento de serviços. Novas noções e técnicas foram desenvolvidas para oferecer soluções inovadoras, tais como redes definidas por software (SDN) para a gestão de rede, virtualização para a optimização da utilização dos recursos e outros, tais como a computação em nuvem e as funções de rede virtualizadas. Esta dissertação pretende gerir automaticamente a emissão de vídeo ao vivo na rede, através da adição de uma arquitetura ao ambiente de rede virtualizado, que auxilie a filtragem de pacotes de vídeo dos do restante tráfego, para um túnel específico, que será gerido com uma prioridade maior, capaz de fornecer melhor serviço aos clientes. Além do desenho da arquitectura, scripts de Python foram usados para detectar os pacotes de vídeo e injetar novas regras no controlador SDN que monitoriza o tráfego ao longo da rede.
Mestrado em Engenharia de Computadores e Telemática
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Yu-ChingYu and 游玉青. "Applying Revised Hungarian Method in Two-layer SDN Control Architecture to Improve Quality of Service for Distributed Server Cluster." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/8e64xs.
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Limantoro, Kevin Darmawan, and Kevin Darmawan Limantoro. "Hierarchical Token Bucket Queuing for Quality of Services Guarantee in Multipath SDN Networks." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/00628095669993555461.
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碩士國立臺灣科技大學
資訊管理系
103
Software Defined Networking (SDN) is a new network paradigm to simplify the networks and ease the network setup and management. Providing Quality of Services (QoS) in SDN, like in traditional networks is also important and attracts many attentions. Currently many researches propose some novel algorithms to provide QoS in SDN networks, but they usually focus on a single path. As we know, Multipath can provide some benefits, such as bandwidth aggregation, better network availability and reliability. Thus, this thesis first implements the mechanism proposed by M.A. Salahuddin to provide multipath SDN networks. The mechanism supporting multipath in SDN networks is not similar to that in traditional networks, due to the specific network architecture and routing mechanism that a SDN network has. Multipath in SDN networks is enabled by the use of a group table. Then this thesis implements Hierarchical Token Bucket (HTB) which not only provides queue and rate limiting for resource reservation but also network slicing functionality to guarantee QoS. The SDN environment used will be tphe simulated from Mininet. HTB can be implemented to this simulated SDN network via Linux Traffic Control (Linux tc) which normally embedded inside Linux Kernel. This feature was enabled due to the OVS (Open Virtual Switch) used by mininet is running over the same Linux architecture. Beside Linux tc, there is another method which is ovs-vsctl but Linux tc is more recommended to use. There are several things need to be concern in the implementation of HTB in the multipath SDN environment, such as the selection SDN component such as controller type, and Openflow version. The reason that HTB is selected as the mechanism to guarantee QoS is because HTB can give fine control over the network slicing with its multiclass queue. Together with HTB filter, HTB can give a specific classification for every network service and packets to support the network virtualization. Experiment results show that HTB can guarantee and limit the rate for each service in multipath SDN network. Therefore, by implementing HTB in multipath SDN environment, the QoS can be guaranteed.
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Ziegler, Wolfgang. "A Framework for managing Quality of Service in Cloud Computing through Service Level Agreements." Doctoral thesis, 2017. http://hdl.handle.net/11858/00-1735-0000-002B-7D14-F.
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Hsiang, Hsin-hung, and 向信宏. "An Empirical Study of Service Quality、Product Quality and Price for Automobile Industry Post-Sale Service on Customer Satisfaction and Customer Loyalty. Sin-Ying Service Factory of Fortune Motors Company as an Example." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/39750845769218870241.
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碩士立德管理學院
科技管理研究所
93
The automobile industry is under great competition in Taiwan, nowadays. The sale amount of new cars decade from year to year, not mentioning the comparison with the past. The position of the market has been altered to the buyer. In order to obtain the market share in the industry, all brand name dealers advertise the low-cost. However, with lower capital expense, zero loan interest, car insurance and free-gift offering, the sale of the new car won’t be the main source of company profit. Instead, the post-sale service and maintenance service are truly the two major paths to increase the long-term profit. Only to enforce the post-sale quality to what customer needs and increase the satisfaction level, which by all means to rise up the customer loyalty, the whole infrastructure can be well-run. Among all the Service Satisfaction Evaluation patterns, the theory advocated in 1985, the Service Quality Level, by Parasuraman 、Zeithaml and Berry, is the most common quoted and adapted one, also called, P.Z.B. Model. This thesis research is under the base of P.Z.B.Model, through the census data to profoundly exam the connection which the Post-Sale Service offered, Service Quality, Product Quality, Price, Customer Satisfaction Level and Customer Loyalty. The research takes the cars with maintaining request in Sin-Ying Service Factory of Fortune Motors Company as major target, with Purposive Sampling study, dispatching 508 census copies. Totally, 486 copies return, 36 copies invalid, and this makes the valid census copy to 450 pieces .The design of this questionnaire is based on Likert’s five point scale analysis；we do a analysis with SPSS 10.0 ,and the methods we applied for data analysis are credibility analysis ,description statistic analysis ,Factor analysis ,PEARSON correlation analysis and Regression analysis . The research reveals the following: 1.The ration of turning back to original Maintaining Shop decades. 2.Aged cars owners are under reluctant will to walk into the Maintaining shop. 3.Brand-named Maintaining Shop charges more than the ordinary. 4.Brand-named Maintaining Shop stays higher service quality. 5.Brand-named Maintaining Shop keeps strict quality policy. Post-Sale Service is a potential market to direct profit, and the service directly affects the customers’ opinion to the Brand Name. Post-Sale Maintaining Service has stepped into a better organized industry, under Trust management. To grab more percentage in the market becomes the only way to success, when talking about the staying the industry reputation and better customer-derived value.
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TRAN, NAM-CUONG, and 陳南強. "Research on Service Quality,Customer Satisfaction in Cargo Industry in Vietnam: A Case Study of Tan Son Nhat Cargo Services." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/33847190692219069425.
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碩士樹德科技大學
金融與風險管理系碩士班
101
In this study, a model has been proposed to show the relationship between customer satisfaction on Tan Son Nhat cargo services and the quality of the services supplied. The exploratory factor analysis and linear regression are well known and widely applied in several fields of research. Presently there are not many practical applications in cargo services in Vietnam, and specifically for measuring customer satisfaction and cargo services. In this research we have applied this methodology on the basis of needs and expectations expressed by customers of a cargo service. The proposed model identifies cargo service quality to improve, with the aim of offering Tan Son Nhat cargo services characterized by higher levels of quality. Result of the study show that reliability, responsiveness, assurance, empathy, and tangible affect cargo service quality; and cargo service quality affect customer satisfaction.
48
Kositchiranant, Notthaporn, and 許美云. "International customers’ satisfaction on service quality of restaurants in Khao San Rd. area in Bangkok, Thailand." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/27904060660060379912.
Full textAbstract:
碩士中國文化大學
觀光事業學系
101
The objective of this research was to discover about the quality and current problems of service. Nowadays, restaurants service industry has developed rapidly and makes a great contribution to service industry. Nevertheless, there are still various problems in the restaurants industry. Therefore, with the evaluation of whether the restaurants in Khao San Rd. area in Thailand are aware of the importance of the employees in service delivery and research on how these restaurants could be able to develop people to deliver excellent which ultimately reveal that service personnel is playing an extremely important role on excellent service delivery in this research. By this research the questions for interview would ask about how customer satisfaction in service quality of restaurant in Khao San Rd. area in Thailand in general will be answered. The thesis was carried out using qualitative method. The research was set to examine the satisfaction of customer with the service provided by restaurants in Khao San Rd. area in Thailand. Among many customers, only 8 international customers were chosen for an interview. The survey was held for about 2 weeks in order to get as many opinions as possible to get enough information and their perspective base on their real experiences from service quality provided in restaurants in Khao San Rd. area in Thailand. Contribution of the thesis: This paper reveals what are the most important dimensions of service quality for tourists and come up with a developed theory could be applicable to other restaurants and provide the guideline for other restaurants to improve the service quality delivery. The process of data analysis of this qualitative research seeks to understand the tourists’ perspective and to be able to answer the research questions. Total of 8 international tourists voluntarily participated in in-depth interviews. The main purpose of this study is to empirically investigate service quality in restaurants in Khao San Rd. area in Thailand. The main goals are to assess restaurants customers’ satisfaction and to identify which are the most important dimensions of service quality that will lead to the most satisfaction to the customer of the restaurants and lead to the next improvement and development of service quality to meet customer’s satisfaction. Suggestions for future research: This study will help the restaurants to improve its service quality for the customer satisfaction. The results achieved from the thesis indicate that the service qualities provided by restaurants in Khao San Rd. area in Thailand should focus on assurance dimension of service quality to make the customers are satisfied with it. The customers felt that the restaurants are always eager to help their customers at its best.
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Chung, Yi-Fei, and 鍾宜霏. "A Study of Importance-Performance Analysis on the Service Quality of Yang San-Lang Art Museum." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/20994119146492312795.
Full textAbstract:
碩士國立臺北教育大學
文化創意產業經營學系
105
The service quality of a museum is primarily determined by the reviews or satisfactory index of its visitors. When the visitors remark higher satisfactory level, its overall review of service quality appears to be better consequently. Regardless tangible or intangible, the service quality provided by the museum usually affects by two factors: the first one is the recognition and expectation of visitors before the touring of the museum; the second one is the actual experience afterwards. The distinction between these two factors represents the outcome of service quality and satisfaction of the museum. With the actualization of two-days off per week system, in addition to the increased income and leisure time, and etc., the opportunities of cultural leisure for the public will be evidently increased. The mechanism to improve the service quality through various activities and facilities has become the major issue for museum administration. Yang San-Lang is one of the nationally well-known precedent painters. In order to preserve his artworks, he founded the first private museum in Taiwan which is called Yang San-Lang Art Museum and later open to the public. The museum also serves to promote art education for the general public. The incentive of this research is to discover the evaluation of service quality of Yang San-Lang Art Museum by its visitors, expecting to enhance its service quality and raise the overall satisfaction. This research is based on both PZB Conceptual Model of Service Quality and SERVQUAL Scale, utilizing Questionnaire Survey to collect evaluation data from visitors regarding all sorts of services by Yang San-Lang Art Museum before and after their visit. Furthermore, the data is going through Importance-Performance Analysis to unveil the advices for its future service improvement. Not only the research results in better understanding in characteristics and behavior patterns of visitors, but also studies the reaction of visitors on how they value the service quality and satisfaction. And it further identifies the relationship between different visitors' background variations and expectation versus actual experience. As a result, according to the analysis, the following three suggestions are proposed for the future reference of their administrative improvement guidelines: 1) Focus on the leisure function and service quality for visitors; 2) Manage the social media for the museum and marketing the museum using mouth-to-mouth strategy; 3) Strengthen the service of tour guide particularly in exhibition contents.
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蔡文晉. "A study on the relationship of Service Quality, Customer Satisfaction and Customer Loyalty─The case of the TAKKYUBIN Home Delivery Service in Sin-Fong area." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/32543088327366118679.
Full textAbstract:
碩士明新科技大學
資訊管理研究所
93
In the recent years, due to the boom of services industries, relevant businesses grow fast. One of them is the Home Delivery industry which is based on the convenience stores spreading over Taiwan. As the consumer loyalty is becoming more and more important to the service industries, the issue about the service quality and the consumer satisfaction is discussed more often. Although many studies show the positive relation among the service quality, the consumer satisfaction and the consumer loyalty, there are only a few studies about how the intereffect of services quality and consumer satisfaction affects consumer loyalty, especially in Home Delivery service. This research investigates those consumers that had used the home delivery service in Sin-Fong area by questionnaire. We apply structural equation model (SEM) and regression approach to test the hypothesis of this research. The results show that the consumer satisfaction acts as a mediation role of influencing the services quality on the formation of consumer loyalty. In addition, user characteristics have influences on the relationship between satisfactory of logistics services quality and loyalty, and satisfying consumer is more important than improving services quality only for home delivery service.