Dans le domaine des réseaux, deux précieux objectifs doivent être atteints, à savoir la QoS et la sécurité, plus particulièrement lorsqu’il s’agit des réseaux à caractère critique et à fortes contraintes temporelles. Malheureusement, un conflit existe : tandis que la QoS œuvre à réduire les temps de traitement, les mécanismes de sécurité quant à eux requièrent d’importants temps de traitement et causent, par conséquent, des délais et dégradent la QoS. Par ailleurs, les systèmes temps réel, la QoS et la sécurité ont très souvent été étudiés séparément, par des communautés différentes. Dans le contexte des réseaux avioniques de données, de nombreux domaines et applications, de criticités différentes, échangent mutuellement des informations, souvent à travers des passerelles. Il apparaît clairement que ces informations présentent différents niveaux de sensibilité en termes de sécurité et de QoS. Tenant compte de cela, le but de cette thèse est d’accroître la robustesse des futures générations de réseaux avioniques de données en contrant les menaces de sécurité et évitant les ruptures de trafic de données. A cet effet, nous avons réalisé un état de l’art des mécanismes de sécurité, de la QoS et des applications à contraintes temporelles. Nous avons, ensuite étudié la nouvelle génération des réseaux avioniques de données. Chose qui nous a permis de déterminer correctement les différentes menaces de sécurité. Sur la base de cette étude, nous avons identifié à la fois les exigences de sécurité et de QoS de cette nouvelle génération de réseaux avioniques. Afin de les satisfaire, nous avons proposé une architecture de passerelle de sécurité tenant compte de la QoS pour protéger ces réseaux avioniques et assurer une haute disponibilité en faveur des données critiques. Pour assurer l’intégration des différentes composantes de la passerelle, nous avons développé une table de session intégrée permettant de stocker toutes les informations nécessaires relatives aux sessions et d’accélérer les traitements appliqués aux paquets (filtrage à états, les traductions d’adresses NAT, la classification QoS et le routage). Cela a donc nécessité, en premier lieu, l'étude de la structure existante de la table de session puis, en second lieu, la proposition d'une toute nouvelle structure répondant à nos objectifs. Aussi, avons-nous présenté un algorithme permettant l’accès et l’exploitation de la nouvelle table de session intégrée. En ce qui concerne le composant VPN IPSec, nous avons détecté que le trafic chiffré par le protocole ESP d’IPSec ne peut pas être classé correctement par les routeurs de bordure. Afin de surmonter ce problème, nous avons développé un protocole, Q-ESP, permettant la classification des trafics chiffrés et offrant les services de sécurité fournis par les protocoles AH et ESP combinés. Plusieurs techniques de gestion de bande passante ont été développées en vue d’optimiser la gestion du trafic réseau. Pour évaluer les performances offertes par ces techniques et identifier laquelle serait la plus appropriée dans notre cas, nous avons effectué une comparaison basée sur le critère du délai, par le biais de tests expérimentaux. En dernière étape, nous avons évalué et comparé les performances de la passerelle de sécurité que nous proposons par rapport à trois produits commerciaux offrant les fonctions de passerelle de sécurité logicielle en vue de déterminer les points forts et faibles de notre implémentation pour la développer ultérieurement. Le manuscrit s’organise en deux parties : la première est rédigée en français et représente un résumé détaillé de la deuxième partie qui est, quant à elle, rédigée en anglais. / QoS and security are two precious objectives for network systems to attain, especially for critical networks with temporal constraints. Unfortunately, they often conflict; while QoS tries to minimize the processing delay, strong security protection requires more processing time and causes traffic delay and QoS degradation. Moreover, real-time systems, QoS and security have often been studied separately and by different communities. In the context of the avionic data network various domains and heterogeneous applications with different levels of criticality cooperate for the mutual exchange of information, often through gateways. It is clear that this information has different levels of sensitivity in terms of security and QoS constraints. Given this context, the major goal of this thesis is then to increase the robustness of the next generation e-enabled avionic data network with respect to security threats and ruptures in traffic characteristics. From this perspective, we surveyed the literature to establish state of the art network security, QoS and applications with time constraints. Then, we studied the next generation e-enabled avionic data network. This allowed us to draw a map of the field, and to understand security threats. Based on this study we identified both security and QoS requirements of the next generation e-enabled avionic data network. In order to satisfy these requirements we proposed the architecture of QoS capable integrated security gateway to protect the next generation e-enabled avionic data network and ensure the availability of critical traffic. To provide for a true integration between the different gateway components we built an integrated session table to store all the needed session information and to speed up the packet processing (firewall stateful inspection, NAT mapping, QoS classification and routing). This necessitates the study of the existing session table structure and the proposition of a new structure to fulfill our objective. Also, we present the necessary processing algorithms to access the new integrated session table. In IPSec VPN component we identified the problem that IPSec ESP encrypted traffic cannot be classified appropriately by QoS edge routers. To overcome this problem, we developed a Q-ESP protocol which allows the classifications of encrypted traffic and combines the security services provided by IPSec ESP and AH. To manage the network traffic wisely, a variety of bandwidth management techniques have been developed. To assess their performance and identify which bandwidth management technique is the most suitable given our context we performed a delay-based comparison using experimental tests. In the final stage, we benchmarked our implemented security gateway against three commercially available software gateways. The goal of this benchmark test is to evaluate performance and identify problems for future research work. This dissertation is divided into two parts: in French and in English respectively. Both parts follow the same structure where the first is an extended summary of the second.

Le Cloud Computing est de plus en plus reconnu comme une nouvelle façon d'utiliser, à la demande, les services de calcul, de stockage et de réseau d'une manière transparente et efficace. Dans cette thèse, nous abordons le problème d'ordonnancement de workflows sur les infrastructures distribuées hétérogènes du Cloud Computing. Les approches d'ordonnancement de workflows existantes dans le Cloud se concentrent principalement sur l'optimisation biobjectif du makespan et du coût. Dans cette thèse, nous proposons des algorithmes d'ordonnancement de workflows basés sur des métaheuristiques. Nos algorithmes sont capables de gérer plus de deux métriques de QoS (Quality of Service), notamment, le makespan, le coût, la fiabilité, la disponibilité et l'énergie dans le cas de ressources physiques. En outre, ils traitent plusieurs contraintes selon les exigences spécifiées dans le SLA (Service Level Agreement). Nos algorithmes ont été évalués par simulation en utilisant (1) comme applications: des workflows synthétiques et des workflows scientifiques issues du monde réel ayant des structures différentes; (2) et comme ressources Cloud: les caractéristiques des services de Amazon EC2. Les résultats obtenus montrent l'efficacité de nos algorithmes pour le traitement de plusieurs QoS. Nos algorithmes génèrent une ou plusieurs solutions dont certaines surpassent la solution de l'heuristique HEFT sur toutes les QoS considérées, y compris le makespan pour lequel HEFT est censé donner de bons résultats. / Cloud Computing is increasingly recognized as a new way to use on-demand, computing, storage and network services in a transparent and efficient way. In this thesis, we address the problem of workflows scheduling on distributed heterogeneous infrastructure of Cloud Computing. The existing workflows scheduling approaches mainly focus on the bi-objective optimization of the makespan and the cost. In this thesis, we propose news workflows scheduling algorithms based on metaheuristics. Our algorithms are able to handle more than two QoS (Quality of Service) metrics, namely, makespan, cost, reliability, availability and energy in the case of physical resources. In addition, they address several constraints according to the specified requirements in the SLA (Service Level Agreement). Our algorithms have been evaluated by simulations. We used (1) synthetic workflows and real world scientific workflows having different structures, for our applications; and (2) the features of Amazon EC2 services for our Cloud. The obtained results show the effectiveness of our algorithms when dealing multiple QoS metrics. Our algorithms produce one or more solutions which some of them outperform the solution produced by HEFT heuristic over all the QoS considered, including the makespan for which HEFT is supposed to give good results.

La thèse porte sur la conception de protocoles de routage pour les réseaux de capteurs. Les problèmes de recherche du routage de données dans un réseau multi-sauts sont d’une part l’optimisation de l’énergie et d’autre part le routage sous contraintes de la qualité de service (QoS) multicritères (e.g., énergie, fiabilité, délai, …). Cette thèse apporte deux contributions par rapport à l’état de l’art : une optimisation d'un protocole de routage probabiliste pour l'équilibre de l'usage d'énergie et un protocole de routage capable de prendre en compte simultanément des métriques de QoS multiples. En effet, pour équilibrer la consommation de l’énergie du routage lorsque des chemins multiples existent, les protocoles de routage probabiliste existants affectent une probabilité de choix à chaque chemin, soit de façon empirique, soit proportionnelle au niveau de l’énergie disponible du chemin. Nous ne savions pas quelles sont les probabilités optimales qui permettent d’avoir la durée de vie maximale du réseau. Cette thèse a permis d’établir ces probabilités optimales à l’aide de la modélisation sous forme d’un problème d’optimisation linéaire. Quant au problème du routage multicritères, bien que des métriques multiples soient définies par RPL (un standard d’IETF), les protocoles existants choisissent la route soit sur une métrique, soit sur une fonction de coût combinant plusieurs (qui introduit par conséquent un biais de pondération), mais jamais plusieurs simultanément. Dans cette thèse, nous avons d’abord évalué numériquement les performances de l’approche « operator calculus algebra » introduit par R. Schott et S. Staples qui définit un algorithme efficace permettant de trouver tous les chemins satisfaisant les contraintes multiples dans un graphe , puis dérivé une version distribuée sur laquelle nous avons conçu un protocole de routage multi-métriques. Ces deux contributions ont été implémentées dans l’environnement Contiki et émulées/simulées sous Cooja (un logiciel permettant de simuler des protocoles des réseaux de capteurs) / In this thesis, we focus on routing protocols for Wireless Sensor Networks (WSNs). The main research problems in the domain of routing data packets in a multi-hop network are the optimisation of the energy and the routing under multi-criteria QoS constraints (e.g., energy, reliability, delay, …). To address these problems, this dissertation proposes two contributions. Firstly, an optimal probabilistic routing protocol which balances the usage of energy and secondly, a routing protocol which is able to simultaneously take into account multiple QoS metrics. In fact, for balancing the energy consumption between the multiple existing links, the existing probabilistic routing protocols assign a probability to each link, either in an empirical way or depending on proportional energy level of the path. We did not know what are the optimal probabilities which lead to the optimal network lifetime. Our first contribution proposes optimal probabilities by modeling and solving a linear programming problem. As for the multi-constrainted QoS routing problem, multiple metrics are defined by RPL (a standard of IETF) but the existing protocols chose paths either according to only one metric or using a single aggregated function with multiple metrics, but never all the metrics simultaneously. In this dissertation, we first evaluate the performance of the operator calculus algebra introduced by R. Schott and S. Staples which defines an efficient algorithm allowing to find all the paths which satisfy the multiple constraints in a graph, and secondly we proposed a distributed version of this algorithm based on which a routing protocol has been designed. Both contributions are implemented in Contiki environment and simulated/emulated under Cooja (a software designed for simulating protocols of WSNs)

Este trabalho investiga a influência dos efeitos da mistura de quatro ondas (FWM -. Four- Wave Mixing) durante o estabelecimento de caminhos ópticos em uma rede GMPLS/DWDM (Generalized MultiProtocol Label Switching/Dense Wavelength Division Multiplexing). Para minimizar seus impactos e assim reduzir o bloqueio total da rede, são propostas estratégias por meio de extensões ao RSVP-TE (Resource Reservation Protocol-Traffic Engineering). A partir de uma plataforma de simulação que emula e integra a camada óptica e o Plano de Controle da arquitetura GMPLS, a solução proposta é validada. Os vários métodos de alocação de comprimentos de onda são avaliados e as contribuições na redução dos sinais interferentes quantificadas. Para minimizar o bloqueio na rede, uma nova classe de métodos de alocação, classificados como híbridos, é definida e seu desempenho é avaliado. O bloqueio da rede em função da variação de parâmetros que reforçam a eficiência da FWM, tais como a quantidade e espaçamento entre canais, é observado, confirmando a necessidade de métodos de alocação especialistas para gerenciamento do QoS (Quality of Service) óptico em cada caminho a ser estabelecido. Os resultados obtidos comprovam a eficiência da solução proposta e evidenciam a necessidade de um Plano de Controle GMPLS com acurada visibilidade das restrições da camada física, tanto os efeitos estáticos quanto às degradações associadas ao comportamento dinâmico da rede. / This work investigates the effects of the Four-Wave Mixing (FWM) during the lightpaths establishment in a GMPLS/DWDM (Generalized Multiprotocol Label Switching / Dense Wavelength Division Multiplexing) network. In order to minimize their impacts and thus reduce network blocking, strategies based on RSVP-TE (Resource Reservation Protocol- Traffic Engineering) extensions are proposed. The proposed solution is validated using a simulation platform that integrates and emulates the optical layer and the GMPLS Control Plane. The various wavelength allocation methods are evaluated and their contributions on the reduction of interfering signals are quantified. In order to minimize the network blocking, a new class of allocation methods (classified as hybrids) is defined and its performance is evaluated. The network blocking caused by the parameters that enhance the FWM efficiency, such as the number and spacing between channels, is also observed, confirming the need of specialized wavelength allocation methods for managing the optical QoS for each lightpath. The results obtained ascertain that the proposed solution is efficient and demonstrate the need for a GMPLS Control Plane endowed with an accurate visibility of the restrictions in the physical layer, concerning both static and dynamic effects.

Made available in DSpace on 2016-04-04T18:31:26Z (GMT). No. of bitstreams: 1 Marcelus Guirardello.pdf: 2153688 bytes, checksum: be50be16f89d021ebb7cf89fb146485c (MD5) Previous issue date: 2008-11-21 / This work presents a proposal of politic that prioritize the access to the wireless medium, considering environment conditions. The QoS policy considers the propagation conditions, through the analyze of the signal to noise ratio and type of service. The prioritization proposal considers each access category (AC) of the 802.11e standard, using queues with different priorities. The proposal uses the parameters specified by the 802.11e, through a dedicated firmware. This prioritization enables a new strategy for the QoS policy, for example to provide the station with the highest rate of transmission a biggest probability to access the medium. This work presents an experimental approach, through a channel emulator. The tests consider three different scenarios to evaluate the performance of the original MAC and the performance of queue priority, considering the effects of the parameters CWmin and AIFSN. The experiments developed in the work demonstrate the effectiveness of the proposed policy. / Este trabalho apresenta uma proposta de pol?tica que priorize o acesso sem fio ao meio, considerando as condi??es do ambiente. A pol?tica de QoS considera as condi??es de propaga??o, atrav?s da an?lise da rela??o sinal ru?do e do tipo de servi?o. A prioriza??o proposta considera o acesso cada categoria (AC), do padr?o 802.11e, utilizando filas com diferentes prioridades. A proposta utiliza os par?metros definidos pela 802.11e, atrav?s de um firmware dedicado. Essa prioriza??o possibilita uma nova estrat?gia para a pol?tica de QoS, por exemplo, para fornecer a uma esta??o com taxa mais alta maior probabilidade de acesso ao meio. Este trabalho apresenta uma abordagem experimental, atrav?s de um emulador de canal. Os testes consideram tr?s cen?rios diferentes para avaliar o desempenho da MAC original e do desempenho da prioriza??o de fila proposta, considerando os efeitos dos par?metros CWmin e AIFSN. As experi?ncias desenvolvidas no ?mbito do trabalho demonstram a efic?cia da pol?tica proposta.

Made available in DSpace on 2016-04-04T18:31:30Z (GMT). No. of bitstreams: 1 Luis Fernando Fontolan.pdf: 1957918 bytes, checksum: c54c21cddbc7cc91dd162510efebc7c4 (MD5) Previous issue date: 2010-02-26 / The IEEE802.11 standard assumes that the stations (STAs) of a communications network have the same condictions during medium access, through the usage of the DCF (Distributed Coodination Function). The DCF states that all stations have the same probability of medium access, regardless of transmission rates or signal to noise ratios. Furthermore, such networks also presents an anomaly by which it is possible that a station with low transmission rate may request the channel for an extended period of time. In this context, this work proposes a QoS policy-based implementation based on the 802.11e standard, which aims to maintain a scenario of greater justice in IEEE802.11 networks. In doing so, it is proposed an algorithm to determine a Justice Index associated to a specific network, by examining the STAs connection rate, their type of service and the requirements for customer service. Thus, stations are served at rates that consider the physical characteristics of the network, in order to optimize their resources, from the viewpoint of the service provider. Results were obtained on simulated networks using the NS2 software considering the proposed policy of justice and show that the analyzed scenarios yield network troughput gain or at least result in a condition similar to that obtained without the use of the proposed justice policy. / O padr?o IEEE802.11 foi especificado presumindo condi??es de igualdade em rela??o ao acesso ao meio por parte das STAs de uma rede, pelo emprego do m?todo DCF , onde todas as STAs possuem a mesma probabilidade de acesso ao meio, sem levar em considera??o sua taxa de transmiss?o ou sua rela??o sinal-ru?do. No entanto, ? necess?rio ressaltar que tais redes apresentam uma anomalia, atrav?s da qual ? poss?vel que uma STA com baixa taxa de transmiss?o venha a ocupar o canal por um grande per?odo de tempo. Nesse contexto, esse trabalho apresenta uma proposta de pol?tica de QoS baseada na implementa??o do padr?o 802.11e, que objetiva manter um cen?rio de maior justi?a em redes IEEE802.11. Para isso ? proposto um algoritmo de c?lculo de ?ndice de justi?a atrav?s da an?lise da taxa de conex?o, do tipo de servi?o e dos requisitos necess?rios para atendimento do servi?o. Assim, as STAs s?o servidas a taxas que levam em conta as caracter?sticas f?sicas da rede, de forma a otimizar os seus recursos, do ponto de vista do provedor. Resultados obtidos com a pol?tica proposta em redes simuladas atrav?s do software NS2 demonstram que os cen?rios analisados resultaram em um ganho em rela??o ao troughput da rede ou, no m?nimo, em uma condi??o semelhante ? obtida sem a utiliza??o da pol?tica.

Made available in DSpace on 2016-04-04T18:31:32Z (GMT). No. of bitstreams: 1 Luiz Henrique Biazotto.pdf: 2826699 bytes, checksum: ea3eea233d66bf1af34e5d7f5d20420d (MD5) Previous issue date: 2012-06-28 / Nowadays, the growth of energy consumption is a global concern due to the possibility of having lack of primary sources. Specially, the consume of electrical energy associated with communications network also eached significantly levels. In this context, researches related to energy efficiency are extremely important.Therefore, this work aims to evaluate the consumption of electrical energy related to IEEE802.11 networks, searching for the relation between this consumption and different parameters of QoS. / Atualmente, o crescimento do consumo de energia el?trica se constitui em preocupa??o mundial, devido ? possibilidade de escassez das fontes prim?rias. Em especial, o consumo de energia el?trica associado ?s redes de comunica??o tamb?m atingiu n?veis significativos. Nesse contexto, pesquisas associadas ? ?rea de efici?ncia energ?tica s?o de fundamental import?ncia. Assim, este trabalho teve por objetivo avaliar o consumo de energia el?trica associado a redes IEEE802.11, investigando a rela??o dessa grandeza com diferentes par?metros de Qualidade de Servi?o (QoS).

Esta dissertação de mestrado aborda a Composição de Web services baseada em atributos de Qualidade de Serviço (CWSbQ). Foi selecionado o domínio de sistemas de e-commerce, por se tratar de uma área em franca expansão, tanto no cenário nacional como internacional. Além disso, os sistemas de e-commerce podem se beneficiar da CWSbQ devido à sua interoperabilidade e atendimento aos requisitos de qualidade de serviço de seus clientes. Foram implementados dez algoritmos para resolver esse problema, usando várias técnicas diferentes, sendo elas: busca aleatória, busca exaustiva, busca heurística, busca meta-heurística e um algoritmo híbrido. Foram realizados experimentos de avaliação de desempenho, considerando tamanhos de espaço de busca diferentes e dois deadlines estabelecidos. As principais contribuições deste trabalho foram o desenvolvimento de três novos algoritmos: Heurística Gulosa (HG), Heurística Gulosa 2 (HG2) e Algoritmo Genético Duplamente Híbrido (AGDH); o uso de planejamento de experimentos e avaliação de desempenho para aperfeiçoar Algoritmos Genéticos (AGs) usados no problema de CWSbQ; e o estudo de adequação dos algoritmos de CWSbQ para diferentes situações / This MSc dissertation addresses the QoS-aware Web services composition (QWSC) problem. The field of e-commerce systems was selected because it comprises an area in wide expansion, both in national and international scenarios. Furthermore, e-commerce systems can benefit from QWSC due to its interoperability and compliance to the requirements of quality of service of the customers. Ten algorithms were implemented to solve this problem by using several different techniques, namely: random search, exhaustive search, heuristic search, meta-heuristic and a hybrid algorithm. Performance evaluation was made considering different search space sizes for two different established deadlines. The main contributions of this work were the development of three new algorithms: Greedy Heuristic (GH), Greedy Heuristic 2 (GH2) and Doubly Hybrid Genetic Algorithm (DHGA); the use of planning of experiments and performance evaluation to improve the genetic algorithms (GAs) used in QWSC problem; and a suitability study of QWSC algorithms for different situations

Este trabalho investiga a influência dos efeitos da mistura de quatro ondas (FWM -. Four- Wave Mixing) durante o estabelecimento de caminhos ópticos em uma rede GMPLS/DWDM (Generalized MultiProtocol Label Switching/Dense Wavelength Division Multiplexing). Para minimizar seus impactos e assim reduzir o bloqueio total da rede, são propostas estratégias por meio de extensões ao RSVP-TE (Resource Reservation Protocol-Traffic Engineering). A partir de uma plataforma de simulação que emula e integra a camada óptica e o Plano de Controle da arquitetura GMPLS, a solução proposta é validada. Os vários métodos de alocação de comprimentos de onda são avaliados e as contribuições na redução dos sinais interferentes quantificadas. Para minimizar o bloqueio na rede, uma nova classe de métodos de alocação, classificados como híbridos, é definida e seu desempenho é avaliado. O bloqueio da rede em função da variação de parâmetros que reforçam a eficiência da FWM, tais como a quantidade e espaçamento entre canais, é observado, confirmando a necessidade de métodos de alocação especialistas para gerenciamento do QoS (Quality of Service) óptico em cada caminho a ser estabelecido. Os resultados obtidos comprovam a eficiência da solução proposta e evidenciam a necessidade de um Plano de Controle GMPLS com acurada visibilidade das restrições da camada física, tanto os efeitos estáticos quanto às degradações associadas ao comportamento dinâmico da rede. / This work investigates the effects of the Four-Wave Mixing (FWM) during the lightpaths establishment in a GMPLS/DWDM (Generalized Multiprotocol Label Switching / Dense Wavelength Division Multiplexing) network. In order to minimize their impacts and thus reduce network blocking, strategies based on RSVP-TE (Resource Reservation Protocol- Traffic Engineering) extensions are proposed. The proposed solution is validated using a simulation platform that integrates and emulates the optical layer and the GMPLS Control Plane. The various wavelength allocation methods are evaluated and their contributions on the reduction of interfering signals are quantified. In order to minimize the network blocking, a new class of allocation methods (classified as hybrids) is defined and its performance is evaluated. The network blocking caused by the parameters that enhance the FWM efficiency, such as the number and spacing between channels, is also observed, confirming the need of specialized wavelength allocation methods for managing the optical QoS for each lightpath. The results obtained ascertain that the proposed solution is efficient and demonstrate the need for a GMPLS Control Plane endowed with an accurate visibility of the restrictions in the physical layer, concerning both static and dynamic effects.

Die vorliegende Diplomarbeit behandelt den Vergleich von QoS- und Mobilitätsmechanismen in der LTE/SAE-Architektur. Nach der Einführung in die LTE/SAE-Architektur wird dargestellt, wie die QoS und die Mobilität im Standard des 3GPP gewährleitet wird. Danach erfolgt eine Untersuchung der Technologien PMIP, Ethernet und MPLS, ob sie sich als Alternativen für die standardisierten Mechanismen eignen. In einem weiteren Kapitel wird ein eigenes Konzept zur QoS- und Mobilitätsverwaltung vorgestellt, und es erfolgen erste Betrachtungen. Abschließend wird ein Ausblick gegeben, wie das vorgestellte eigene Konzept weiter ausgebaut werden könnte.