As redes de computadores têm evoluído para acomodar uma grande variedade de serviços, tais como streaming de vídeos de alta qualidade e entrega de conteúdo sensível a atrasos. Estes serviços têm aumentado a demanda por recursos não originalmente considerados na Internet. Com a promessa de atender novas demandas de rede rapidamente, pesquisadores propuseram Redes Programáveis, nas quais o comportamento dos dispositivos de rede pode ser alterado utilizando aplicativos. Entretanto, tal comportamento pode não ser um consenso entre usuários da rede. O surgimento de Redes Virtualizadas superou tal questão, ao permitir a coexistência de múltiplas redes virtuais sobre a mesma infraestrutura física. A fim de se obter redes virtuais isoladas com comportamento programável, foram propostas as Redes Virtuais Programáveis (RVP). Diante dessa nova realidade, os administradores de rede não estão mais olhando unicamente para dispositivos de rede. Eles estão olhando para um sistema composto de dispositivos e aplicativos de rede que definem o comportamento individual de cada rede virtual. Isso requer não apenas novas ferramentas e abordagens de gerenciamento, além disso, exige a revisão de conceitos tradicionais sobre redes. Implementações de RVP são encontradas principalmente em testbeds e ambientes de Computação em Nuvem. Testbeds são muito propícios à inovação, mas possuem fortes limitações no que diz respeito a migração de soluções experimentais para produção. Por outro lado, computação em nuvem é um ótimo ambiente de produção, mas possui restrições de flexibilidade e inovação, uma vez que as soluções de rede adotadas geralmente são proprietárias. Portanto, nesta dissertação introduz-se um novo modelo de negócio que permite a criação de soluções inovadoras em ambientes de produção, a Programabilidade de Redes como um Serviço (NPaaS). Diferente do modelo de negócio de redes tradicionais, onde os usuários finais são apenas consumidores dos serviços de rede já disponíveis, em NPaaS os usuários finais também são capazes de desenvolver e implantar novas soluções de rede. Para apoiar NPaaS, propõe-se uma plataforma de gerenciamento de rede virtual programável, chamada ProViNet. Essa plataforma fornece a arquitetura de software e estratégias necessárias para permitir a implantação e gestão NPaaS. Uma avaliação qualitativa do modelo de negócio NPaaS foi realizada, o resultado foi contrastado com alguns dos modelos de negócio praticados atualmente. Assim, enfatizando a singularidade do NPaaS. Enquanto isso, uma avaliação experimental foi realizada para demonstrar a viabilidade da plataforma ProViNet. Os resultados mostraram que NPaaS representa uma alternativa promissora para ambientes de rede virtual com acesso público, como as nuvens públicas. Além disso, uma avaliação quantitativa do protótipo da plataforma demonstrou a viabilidade técnica e provou que aplicativos de rede desenvolvidos usando BPMN são capazes de executar com desempenho aceitáveis. / Computer networks have evolved to accommodate a wide variety of services, such as streaming of high quality videos and delay-sensitive content delivery. These services have increased the demand for features not originally considered in the Internet. Aiming to address novel network demands quickly, some researchers proposed Programmable Networks, in which network devices behavior can be changed using applications. Notwithstanding, such behavior might not be a consensus between computer network stakeholders. The emergence of Virtualized Networks overcame this issue by allowing the coexistence of multiple virtual networks on the same physical infrastructure. Finally, the convergence of programmability and virtualization techniques are explored within a third concept, the Programmable Virtual Networks (PVN). Faced with this new reality, network administrators are no longer just looking at network devices. They are looking at a system made of virtual devices and applications that define each virtual network behavior. This requires not just new tools and management approaches, over and above that, requires new thinking. PVN deployments are found mostly in shared experimental facilities (also known as testbeds) and Cloud Computing environments. Testbeds are very innovation friendly, but with strong limitations in regards to taking experimental solutions to production. On the other hand, Cloud computing is a great production environment, but presents flexibility and innovation restrictions once network solutions adopted are usually proprietary. Therefore, in this dissertation it is introduced Network Programming as a Service (NPaaS), a new business model that aims to facilitate the conduct of innovative solutions for production environments. Different from traditional network business models, where end-users are just consumers of network services already available, in NPaaS, end-users are also able to develop and deploy novel network solutions. To support NPaaS, Programmable Virtual Network management platform is proposed. Such platform, named ProViNet, provides all architectural and technical features necessary to enable NPaaS deployment and management. A qualitative evaluation of the NPaaS business model was performed, and the result was contrasted with some of the current models, thus, emphasizing the singularity of NPaaS. In the meanwhile, an experimental evaluation was conducted to demonstrate the feasibility of ProViNet platform. Results have shown that NPaaS represent a promising alternative for virtual network environments with public access such as public clouds. Moreover, a quantitative evaluation of the platform prototype demonstrated the technical feasibility and proved that network applications developed using BPMN are able to run with acceptable performance rates.

Le secteur des télécommunications passe par une phase délicate en raison de profondes mutations technologiques, principalement motivées par le développement de l'Internet. Elles ont un impact majeur sur l'industrie des télécommunications dans son ensemble et, par conséquent, sur les futurs déploiements des nouveaux réseaux, plateformes et services. L'évolution de l'Internet a un impact particulièrement fort sur les opérateurs des télécommunications (Telcos). En fait, l'industrie des télécommunications est à la veille de changements majeurs en raison de nombreux facteurs, comme par exemple la banalisation progressive de la connectivité, la domination dans le domaine des services de sociétés du web (Webcos), l'importance croissante de solutions à base de logiciels et la flexibilité qu'elles introduisent (par rapport au système statique des opérateurs télécoms). Cette thèse élabore, propose et compare les scénarios possibles basés sur des solutions et des approches qui sont technologiquement viables. Les scénarios identifiés couvrent un large éventail de possibilités: 1) Telco traditionnel; 2) Telco transporteur de Bits; 3) Telco facilitateur de Plateforme; 4) Telco fournisseur de services; 5) Disparition des Telco. Pour chaque scénario, une plateforme viable (selon le point de vue des opérateurs télécoms) est décrite avec ses avantages potentiels et le portefeuille de services qui pourraient être fournis / The telecommunications industry is going through a difficult phase because of profound technological changes, mainly originated by the development of the Internet. They have a major impact on the telecommunications industry as a whole and, consequently, the future deployment of new networks, platforms and services. The evolution of the Internet has a particularly strong impact on telecommunications operators (Telcos). In fact, the telecommunications industry is on the verge of major changes due to many factors, such as the gradual commoditization of connectivity, the dominance of web services companies (Webcos), the growing importance of software based solutions that introduce flexibility (compared to static system of telecom operators). This thesis develops, proposes and compares plausible future scenarios based on future solutions and approaches that will be technologically feasible and viable. Identified scenarios cover a wide range of possibilities: 1) Traditional Telco; 2) Telco as Bit Carrier; 3) Telco as Platform Provider; 4) Telco as Service Provider; 5) Telco Disappearance. For each scenario, a viable platform (from the point of view of telecom operators) is described highlighting the enabled service portfolio and its potential benefits

<p> </p> <p>Productive programmable accelerators, like GPUs, have been developed for generations to support programming features. The ever-increasing performance improves the usability of programming features on GPUs, and these programming features further ease the porting of code and data structure from CPU to GPU. However, GPU programming features, such as function call or runtime polymorphism, have not been well explored or optimized.</p> <p>I identify efficient and productive GPU programming as a potential area to exploit. Although many programming paradigms are well studied and efficiently supported on CPU architectures, their performance on novel accelerators, like GPUs, has never been studied, evaluated, and made perfect. For instance, programming with functions is a commonplace programming paradigm that shapes software programs with modularity and simplifies code with reusability. A large amount of work has been proposed to alleviate function calling overhead on CPUs, however, less paper talked about its deficiencies on GPUs. On the other hand, polymorphism amplifies an object’s behaviors at runtime. A body of work targets</p> <p>efficient polymorphism on CPUs, but no work has ever discussed this feature under GPU contexts.</p> <p><br></p> <p>In this dissertation, I discussed those two programming features on GPU architectures. First, I performed the first study to identify the deficiency of GPU polymorphism. I created micro-benchmarks to evaluate virtual function overhead in controlled settings and the first GPU polymorphic benchmark suite, ParaPoly, to investigate real-world scenarios. The micro-benchmarks indicated that the virtual function overhead is usually negligible but can</p> <p>cause up to a 7x slowdown. Virtual functions in ParaPoly show a geometric meaning of 77% overhead on GPUs compared to the function’s inlined version. Second, I proposed two novel techniques that determine an object’s type only by its address pointer to improve GPU polymorphism. The first technique, Coordinated Object</p> <p>Allocation and function Lookup (COAL) is a software-only technique that uses the object’s address to determine its type. The second technique, TypePointer, needs hardware modification to embed the object’s type information into its address pointer. COAL achieves 80%  and 6% improvements, and TypePointer achieves 90% and 12% over contemporary CUDA and our type-based SharedOA.</p> <p>Considering the growth of GPU programs, function calls become a pervasive paradigm to be consistently used on GPUs. I also identified the overhead of excessive register spilling with function calls on GPU. To diminish this cost, I proposed a novel Massively Multithreaded Register Windowing technique with Variable Size Register Window and Register-Conscious Warp Scheduling. Our techniques improve the representative workloads with a geometric</p> <p>mean of 1.18x with only 1.8% hardware storage overhead.</p>

The telecommunications industry is going through a difficult phase because of profound technological changes, mainly originated by the development of the Internet. They have a major impact on the telecommunications industry as a whole and, consequently, the future deployment of new networks, platforms and services. The evolution of the Internet has a particularly strong impact on telecommunications operators (Telcos). In fact, the telecommunications industry is on the verge of major changes due to many factors, such as the gradual commoditization of connectivity, the dominance of web services companies (Webcos), the growing importance of software based solutions that introduce flexibility (compared to static system of telecom operators). This thesis develops, proposes and compares plausible future scenarios based on future solutions and approaches that will be technologically feasible and viable. Identified scenarios cover a wide range of possibilities: 1) Traditional Telco; 2) Telco as Bit Carrier; 3) Telco as Platform Provider; 4) Telco as Service Provider; 5) Telco Disappearance. For each scenario, a viable platform (from the point of view of telecom operators) is described highlighting the enabled service portfolio and its potential benefits

<p>  Modern datacenter network applications continue to demand ultra low latencies and very high throughputs. At the same time, network infrastructure keeps achieving higher speeds and larger bandwidths. We still need better network management solutions to keep these two demand and supply fronts go hand-in-hand. There are key metrics that define network performance such as flow completion time (the lower the better), throughput (the higher the better), and end-to-end latency (the lower the better) that are mainly governed by how effectively network application get their fair share of network resources. We observe that buffer utilization on network switches gives a very accurate indication of network performance. Therefore, network buffer management is important in modern datacenter networks, and other network management solutions can be efficiently built around buffer utilization. This dissertation presents three solutions based on buffer use on network switches.</p> <p>  This dissertation consists of three main sections. The first section is on a specification language for buffer management in modern programmable switches. The second section is on a congestion control solution for Remote Direct Memory Access (RDMA) networks. The third section is on a solution to head-of-the-line blocking in modern datacenter networks.</p>

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 services / Software-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