A Virtualização de Funções de Rede (NFV – Network Function Virtualization) é um novo conceito arquitetural que está remodelando a operação de funções de rede (e.g., firewall, gateways e proxies). O conceito principal de NFV consiste em desacoplar a lógica de funções de rede dos dispositivos de hardware especializados e, desta forma, permite a execução de imagens de software sobre hardware de prateleira (COTS – Commercial Off-The-Shelf). NFV tem o potencial para tornar a operação das funções de rede mais flexíveis e econômicas, primordiais em ambientes onde o número de funções implantadas pode chegar facilmente à ordem de centenas. Apesar da intensa atividade de pesquisa na área, o problema de posicionar e encadear funções de rede virtuais (VNF – Virtual Network Functions) de maneira escalável e com baixo custo ainda apresenta uma série de limitações. Mais especificamente, as estratégias existentes na literatura negligenciam o aspecto de encadeamento de VNFs (i.e., objetivam sobretudo o posicionamento), não escalam para o tamanho das infraestruturas NFV (i.e., milhares de nós com capacidade de computação) e, por último, baseiam a qualidade das soluções obtidas em custos operacionais não representativos. Nesta tese, aborda-se o posicionamento e o encadeamento de funções de rede virtualizadas (VNFPC – Virtual Network Function Placement and Chaining) como um problema de otimização no contexto intra- e inter-datacenter. Primeiro, formaliza-se o problema VNFPC e propõe-se um modelo de Programação Linear Inteira (ILP) para resolvêlo. O objetivo consiste em minimizar a alocação de recursos, ao mesmo tempo que atende aos requisitos e restrições de fluxo de rede. Segundo, aborda-se a escalabilidade do problema VNFPC para resolver grandes instâncias do problema (i.e., milhares de nós NFV). Propõe-se um um algoritmo heurístico baseado em fix-and-optimize que incorpora a meta-heurística Variable Neighborhood Search (VNS) para explorar eficientemente o espaço de solução do problema VNFPC. Terceiro, avalia-se as limitações de desempenho e os custos operacionais de estratégias típicas de aprovisionamento ambientes reais de NFV. Com base nos resultados empíricos coletados, propõe-se um modelo analítico que estima com alta precisão os custos operacionais para requisitos de VNFs arbitrários. Quarto, desenvolve-se um mecanismo para a implantação de encadeamentos de VNFs no contexto intra-datacenter. O algoritmo proposto (OCM – Operational Cost Minimization) baseia-se em uma extensão da redução bem conhecida do problema de emparelhamento ponderado (i.e., weighted perfect matching problem) para o problema de fluxo de custo mínimo (i.e., min-cost flow problem) e considera o desempenho das VNFs (e.g., requisitos de CPU), bem como os custos operacionais estimados. Os resultados alcaçados mostram que o modelo ILP proposto para o problema VNFPC reduz em até 25% nos atrasos fim-a-fim (em comparação com os encadeamentos observados nas infra-estruturas tradicionais) com um excesso de provisionamento de recursos aceitável – limitado a 4%. Além disso, os resultados evidenciam que a heurística proposta (baseada em fix-and-optimize) é capaz de encontrar soluções factíveis de alta qualidade de forma eficiente, mesmo em cenários com milhares de VNFs. Além disso, provê-se um melhor entendimento sobre as métricas de desempenho de rede (e.g., vazão, consumo de CPU e capacidade de processamento de pacotes) para as estratégias típicas de implantação de VNFs adotadas infraestruturas NFV. Por último, o algoritmo proposto no contexto intra-datacenter (i.e. OCM) reduz significativamente os custos operacionais quando comparado aos mecanismos de posicionamento típicos uti / Network Function Virtualization (NFV) is a novel concept that is reshaping the middlebox arena, shifting network functions (e.g. firewall, gateways, proxies) from specialized hardware appliances to software images running on commodity hardware. This concept has potential to make network function provision and operation more flexible and cost-effective, paramount in a world where deployed middleboxes may easily reach the order of hundreds. Despite recent research activity in the field, little has been done towards scalable and cost-efficient placement & chaining of virtual network functions (VNFs) – a key feature for the effective success of NFV. More specifically, existing strategies have neglected the chaining aspect of NFV (focusing on efficient placement only), failed to scale to hundreds of network functions and relied on unrealistic operational costs. In this thesis, we approach VNF placement and chaining as an optimization problem in the context of Inter- and Intra-datacenter. First, we formalize the Virtual Network Function Placement and Chaining (VNFPC) problem and propose an Integer Linear Programming (ILP) model to solve it. The goal is to minimize required resource allocation, while meeting network flow requirements and constraints. Then, we address scalability of VNFPC problem to solve large instances (i.e., thousands of NFV nodes) by proposing a fixand- optimize-based heuristic algorithm for tackling it. Our algorithm incorporates a Variable Neighborhood Search (VNS) meta-heuristic, for efficiently exploring the placement and chaining solution space. Further, we assess the performance limitations of typical NFV-based deployments and the incurred operational costs of commodity servers and propose an analytical model that accurately predict the operational costs for arbitrary service chain requirements. Then, we develop a general service chain intra-datacenter deployment mechanism (named OCM – Operational Cost Minimization) that considers both the actual performance of the service chains (e.g., CPU requirements) as well as the operational incurred cost. Our novel algorithm is based on an extension of the well-known reduction from weighted matching to min-cost flow problem. Finally, we tackle the problem of monitoring service chains in NFV-based environments. For that, we introduce the DNM (Distributed Network Monitoring) problem and propose an optimization model to solve it. DNM allows service chain segments to be independently monitored, which allows specialized network monitoring requirements to be met in a efficient and coordinated way. Results show that the proposed ILP model for the VNFPC problem leads to a reduction of up to 25% in end-to-end delays (in comparison to chainings observed in traditional infrastructures) and an acceptable resource over-provisioning limited to 4%. Also, we provide strong evidences that our fix-and-optimize based heuristic is able to find feasible, high-quality solutions efficiently, even in scenarios scaling to thousands of VNFs. Further, we provide indepth insights on network performance metrics (such as throughput, CPU utilization and packet processing) and its current limitations while considering typical deployment strategies. Our OCM algorithm reduces significantly operational costs when compared to the de-facto standard placement mechanisms used in Cloud systems. Last, our DNM model allows finer grained network monitoring with limited overheads. By coordinating the placement of monitoring sinks and the forwarding of network monitoring traffic, DNM can reduce the number of monitoring sinks and the network resource consumption (54% lower than a traditional method).

In this project, two tests were performed. On the first test, Mininet-WiFi was used to simulate a Software Defined Network to demonstrate Mininet-WiFi’ s ability to be used as the Software Defined Network emulator which can also be integrated to the existing network using a Network Virtualized Function (NVF). A typical organization’s computer network was simulated which consisted of a website hosted on the LAMP (Linux, Apache, MySQL, PHP) virtual machine, and an F5 application delivery controller (ADC) which provided load balancing of requests sent to the web applications. A website page request was sent from the virtual stations inside Mininet-WiFi. The request was received by the application delivery controller, which then used round robin technique to send the request to one of the web servers on the LAMP virtual machine. The web server then returned the requested website to the requesting virtual stations using the simulated virtual network. The significance of these results is that it presents Mininet-WiFi as an emulator, which can be integrated into a real programmable networking environment offering a portable, cost effective and easily deployable testing network, which can be run on a single computer. These results are also beneficial to modern network deployments as the live network devices can also communicate with the testing environment for the data center, cloud and mobile provides. On the second test, a Software Defined Network was created in Mininet using python script. An external interface was added to enable communication with the network outside of Mininet. The amazon web services elastic computing cloud was used to host an OpenDaylight controller. This controller is used as a control plane device for the virtual switch within Mininet. In order to test the network, a webserver hosted on the Emulated Virtual Environment – Next Generation (EVENG) software is connected to Mininet. EVE-NG is the Emulated Virtual Environment for networking. It provides tools to be able to model virtual devices and interconnect them with other virtual or physical devices. The OpenDaylight controller was able to create the flows to facilitate communication between the hosts in Mininet and the webserver in the real-life network. / Electrical and Mining Engineering

[ES] La complejidad en la gestión de las redes de comunicación tradicionales, así como su poca escalabilidad y flexibilidad, supone un obstáculo para el desarrollo y consolidación de nuevas tecnologías emergentes como es el caso del Internet de las Cosas (Internet of Things), dónde la facilidad para el intercambio y manejo de grandes volúmenes de datos heterogéneos procedentes de sensores es un requisito clave para el correcto funcionamiento del sistema. El Internet de las Cosas se define cómo la interconexión digital de objetos cotidianos dotados de inteligencia (Smart devices) a través de redes de comunicación de datos ya sean públicas (Internet) o privadas. Sin embargo, el Internet de las Cosas no sólo está compuesto por estos dispositivos, toda la infraestructura, plataformas, aplicaciones y servicios que ayudan a los datos a viajar desde los dispositivos origen y hacia sus diferentes destinos, y la gestión de estos también forman parte del denominado Internet de las Cosas. El almacenamiento, análisis, procesado y gestión masiva de dichos datos es lo que se denomina Big Data, y está compuesto de grandes cantidades de datos (massive data) estructurados en diferentes formatos, modelos de datos y protocolos, lo que dificulta su tratamiento y su intercambio a través de las redes de datos convencionales. Ante esta problemática la implementación de redes virtuales definidas por software se presenta como una posible solución para dotar de flexibilidad, escalabilidad y sencillez de gestión a las redes que interconectan estos dispositivos, plataformas y otros elementos IoT, permitiendo una visión global, una gestión centralizada y un desarrollo de servicios a nivel de red específicos para los entornos de Internet de las Cosas. Este proyecto se presenta como una aproximación de estas dos tecnologías y tendrá como objetivo el diseño de una solución donde probar las herramientas de control de redes definidas por software o programables (SDN) y las funciones virtuales de redes (NFV) aplicadas a despliegues de Internet de las Cosas (IoT) de forma que se puedan demostrar sus ventajas e implicaciones y se puedan descubrir nuevas líneas de desarrollo sobre esta base. / [CA] La complexitat en la gestió de les xarxes de comunicació tradicionals, així com la seua poca escalabilitat i flexibilitat, suposa un obstacle per al desenvolupament i consolidació de noves tecnologies emergents com és el cas de la Internet de les Coses (Internet of Things), on la facilitat per a l'intercanvi i maneig de grans volums de dades heterogènies procedents de sensors és un requisit clau per al correcte funcionament del sistema. La Internet de les Coses es defineix com la interconnexió digital d'objectes quotidians dotats d'intel·ligència (Smart devices) a través de xarxes de comunicació de dades ja siguen públiques (Internet) o privades. No obstant això, la Internet de les Coses no sols està compost per aquests dispositius, tota la infraestructura, plataformes, aplicacions i serveis que ajuden les dades a viatjar des dels dispositius d'origen i cap a les seues diferents destinacions, i la gestió d'aquests també formen part de la denominada Internet de les Coses. L'emmagatzematge, anàlisi, processament i gestió massiva d'aquestes dades és el que es denomina Big Data, i està compost de grans quantitats de dades (massive data) estructurats en diferents formats, models de dades i protocols, la qual cosa dificulta el seu tractament i el seu intercanvi a través de les xarxes de dades convencionals. Davant aquesta problemàtica la implementació de xarxes virtuals definides per software es presenta com una possible solució per a dotar de flexibilitat, escalabilitat i senzillesa de gestió a les xarxes que interconnecten aquests dispositius, plataformes i altres elements IoT, permetent una visió global, una gestió centralitzada i un desenvolupament de serveis a nivell de xarxa específics per als entorns d'Internet de les Coses. Aquest projecte es presenta com una aproximació d'aquestes dues tecnologies i tindrà com a objectiu el disseny d'una solució on provar les eines de control de xarxes definides per software o programables (SDN) i les funcions virtuals de xarxes (NFV) aplicades a desplegaments d'Internet de les Coses (IoT) de manera que es puguen demostrar els seus avantatges i implicacions, i es puguen descobrir noves línies de desenvolupament sobre aquesta base. / [EN] Nowadays, the complexity of traditional network administration, together with the lack of scalability and flexibility, has been a challenge for the proper development and integration of new emerging technologies which make use of this network. As an example, we have the so-called Internet of Things (IoT). The principal IoT network requirement that enables the growth of this paradigm is the need to facilitate high data volume exchange and administration, from very heterogeneous sources. The IoT concept is defined as the digital interconnection of daily objects endowed with more "intelligence" (Smart devices) through a data communication network either public (Internet) or private. However, this technological trend does not only depend on the "smart devices", but on the whole infrastructure, platforms, frameworks, services, and applications that helps data to travel from the source devices to their different destinations. Also, the handling of the massive volumes of data extracted from those smart devices, their storage, processing, and analysis, known as Big Data, is a key part of this paradigm. This data is gathered from very different sources, and hence, it has diverse data structures and formats. Moreover, it is exchanged using various network protocols (LoRa, CoAp, etc.) which hinder its management and communication through conventional networks, that were not created for such data traffic. Given this problem, several technological approaches have emerged to solve it. Virtual software-defined networking is presented as a possible solution to provide flexibility, scalability, and simplicity of management to the networks that interconnect these devices, platforms, services, and other IoT elements. The virtualization of the network infrastructure, includes an extra layer of abstraction, thus providing a holistic vision of the network and centralizing the administration of its elements and the development of specific network services for IoT deployments. This project is presented as an approximation of these two technological paradigms and will have as the main objective the design of an architectural blueprint and testbed were testing the control tools of software-defined networks (SDN) and the virtualized network functions (NFV) applied to IoT deployments. Thereby, its advantages and implications can be evaluated, and new lines of development can be discovered on this base. / Suárez De Puga García, J. (2022). Especificación e implementación de un sistema de red definida por software con funciones virtuales adaptadas a despliegues de Internet de las cosas [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/181555 / TESIS

In this project, two tests were performed. On the first test, Mininet-WiFi was used to simulate a Software Defined Network to demonstrate Mininet-WiFi’ s ability to be used as the Software Defined Network emulator which can also be integrated to the existing network using a Network Virtualized Function (NVF). A typical organization’s computer network was simulated which consisted of a website hosted on the LAMP (Linux, Apache, MySQL, PHP) virtual machine, and an F5 application delivery controller (ADC) which provided load balancing of requests sent to the web applications. A website page request was sent from the virtual stations inside Mininet-WiFi. The request was received by the application delivery controller, which then used round robin technique to send the request to one of the web servers on the LAMP virtual machine. The web server then returned the requested website to the requesting virtual stations using the simulated virtual network. The significance of these results is that it presents Mininet-WiFi as an emulator, which can be integrated into a real programmable networking environment offering a portable, cost effective and easily deployable testing network, which can be run on a single computer. These results are also beneficial to modern network deployments as the live network devices can also communicate with the testing environment for the data center, cloud and mobile provides. On the second test, a Software Defined Network was created in Mininet using python script. An external interface was added to enable communication with the network outside of Mininet. The amazon web services elastic computing cloud was used to host an OpenDaylight controller. This controller is used as a control plane device for the virtual switch within Mininet. In order to test the network, a webserver hosted on the Emulated Virtual Environment – Next Generation (EVENG) software is connected to Mininet. EVE-NG is the Emulated Virtual Environment for networking. It provides tools to be able to model virtual devices and interconnect them with other virtual or physical devices. The OpenDaylight controller was able to create the flows to facilitate communication between the hosts in Mininet and the webserver in the real-life network. / Electrical and Mining Engineering / M. Tech. (Electrical Engineering)