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).

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).

Pessoas e organizações ao redor do globo utilizam aplicações multimídia para interação e comunicação. Existe notável crescimento de tráfego característico dessas aplicações, uma vez que há convergência de voz e dados para um modelo único de transporte. As redes de computadores, por suportar tais aplicações cadenciam desafios e oportunidades de negócios que os operadores têm aproveitado. Por outro lado, os usuários experimentam serviços com qualidades cada vez mais refinados, mesmo assim, existem aspectos que devem ser tratados para elevar a qualidade de experiência percebida pelos usuários ao consumir serviços ofertados sobre a internet. Métricas de QoS usualmente são baseadas nos usuários ou na rede, por isso, conceitos como NFV e SDN permitem aprimorar e expandir a perspectiva de oferta de uma camada de abstração para desenvolvimento de soluções flexíveis, que visam lidar com aplicações multimídia ofertadas em nuvem. Não obstante, a construção dessas soluções deve ser calcada em aspectos intrínsecos ao conceito de Internet do Futuro que preconiza soluções virtualizadas, flexíveis, convergentes, escaláveis, orientadas a contexto, seguras e melhor gerenciadas. Este trabalho propõe uma abordagem para mitigar a distância das aplicações com os recursos de rede e computação. Usualmente as aplicações desconhecem características de hardware sobre o qual elas operam; quanto a rede, mesmo com esforços em vários níveis da pilha de protocolos, desconhece especificidades das aplicações em execução. Há também dificuldade de gerenciamento global de recursos, integração de políticas e acordos de serviço entre operadores. O trabalho visa adicionar uma camada de gerenciamento para elevar os níveis de QoS para aplicações multimídia baseadas em NFV. Para realizar isso, é proposto uma entidade que atua no plano de dados e controle, capaz de orquestrar recursos de rede e de computação simultaneamente para aprimorar QoS em aplicações multimídia. A incorporação dessa entidade conquista melhoramento de QoS por meio da oferta de resiliência na comunicação fim-a-fim de entidades consumidoras dessas aplicações, provê um balanceamento de carga adequado a fim de não comprometer parâmetros de QoS como tempo de resposta, provê escalabilidade sob demanda, promove o conceito de inspeção de pacotes para segmentação de políticas de rede orientada à aplicação, finalmente realiza a separação de plano de dados e controle. A construção e experimentação da solução permitiu diminuir tempos de resposta nas aplicações multimídia; a solução reagiu adequadamente frente a cargas de trabalho heterogêneas no sentido de prover confiabilidade para garantia de QoS; também, o conceito de inspeção de pacotes foi capaz de atuar para diminuir a distância que as aplicações possuem da rede e o hardware sobre o qual elas operam. / People and organizations around the globe use multimedia applications for interaction and communication. There is notable traffic growth characteristic of these applications since there is a convergence of voice and data for a single transport model. Computer networks, because they support such applications, meet the challenges and business opportunities that operators have taken advantage of. On the other hand, users use services with increasingly refined qualities, nevertheless, there are aspects that must be addressed to raise the quality of experience for users when consuming services offered over the internet. QoS metrics are usually user-based or network-based, hence concepts such as NFV and SDN allow to improve and expand the perspective of offering an abstraction layer for the development of flexible solutions that deal with multimedia applications offered in the cloud. Nevertheless, the construction of these solutions must be based on intrinsic aspects to the Future Internet concept that advocates virtualized solutions, flexible, convergent, scalable, context-aware, secure and better managed. This dissertation proposes an approach to mitigate the distance of the applications with the resources of compute and network. Usually, the applications are unaware of the hardware characteristics on which they operate, as for the network, even with several efforts at various levels of the protocol stack, the specificities of running applications are unknown. There is also challenges of managing global resources, integrating policies and service agreements between operators. This work aims to add a management layer to raise the levels of QoS for multimedia applications based on NFV. To accomplish this, an entity that acts on the data and control plane is proposed, capable of orchestrating network and computing resources simultaneously to enhance QoS in multimedia applications. The incorporation of this entity achieves QoS improvement through resiliency in the end-to-end communication of the consumer entity of these applications, provides adequate load balancing in order to avoid compromising QoS parameters such as response time, provides on-demand scalability, improves the concept of package inspection for the segmentation of application-oriented network policies, and finally performs the separation of data and control plane. The construction and experimentation of the solution allowed to reduce response times in the multimedia applications. The solution reacted adequately to heterogeneous workloads in order to provide reliability for QoS guarantee. Furthermore, the concept of packet inspection was able to act to decrease the distance that the applications have from the network and the hardware on which they operate. / Dissertação (Mestrado)

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).

Software orchestrators like Kubernetes are growing in popularity with computer engineers for deploying and running complex software systems. Interestingly, there are now new technical standards being proposed for the telecom industry to begin utilizing software orchestration for the software that runs inside cellular networks. The telecom industry is currently transitioning from 4G to 5G technology. One of the central pieces of this development work is implementing a software orchestrator for 5G networks. This raises some questions about how and why the telecom industry will use software orchestration in their cellular networks. Software orchestration is a complex technology and it is challenging to develop an implementation of a software orchestrator. Some important questions that this thesis addresses are: What do network operators need from this technology? Furthermore, telecom vendors, like Ericsson and Huawei, have developed their own versions of a 5G software orchestrator, which orchestrator should the network operators choose? Furthermore, we investigate what 5G is, why the telecom industry is developing software orchestrators for the 5G roll-out, and importantly, we determine the design requirements that the telecom industry has for these "5G orchestration systems". We interpret and break down technical whitepapers from the industry, and we build a picture of the IT stack of upcoming 5G networks. In our research, we find that software orchestration is being used to deploy and maintain complex software stacks such as software-defined networking (SDN) system that is central to 5G networks. We uncover some of the specializations needed in a software orchestrator for the telecom industry, such as modularity, high-availability, and specialized system integration. With this information, we make feature and design recommendations for 5G orchestrators, and we compile a list of criteria that network operators can use to assess and compare different 5G orchestrators. / Orkestreringsprogramvaror som Kubernetes växer i popularitet med IT ingenjörer för att installera och köra komplexa mjukvarasystem. På grund av pågående transitionen från 4G till 5G, används orkestreringsprogramvaror nu också i mobilnäten. I den här uppsatsen undersöks vad är 5G, varför telekombranschen använder orkestreringsprogramvaror för nya 5G nätverk, och vad krav har telekombranschen på denna "5G orkestreringsprogramvaror". Denna undersökning utförs genom en litteraturstudie. Genom den här undersökningen, det visar sig att orkestreringsprogramvaror används för att installera och köra komplexa mjukvarasystem som är centralt till 5G nätverk. Specialiseringskrav för orkestreringsprogramvaror i telekombranschen upptäcks, som modularitet, hög tillgänglighet, och specialiserad API-hookar. Rekommendationer görs för 5G orkestreringsprogramvarors funktioner, och en lista sammanställas av kriterier som telekomoperatör kan använda för att bedöma och jämföra 5G orkestreringsprogramvaror.

By virtue of the recent technological developments in cloud computing, more applications are deployed in a cloud. Among these modern cloud-based applications, some require bounded and predictable low-latency responses. However, the current cloud infrastructure is unsuitable as it cannot satisfy these requirements, due to many limitations in both hardware and software. This licentiate thesis describes attempts to reduce the latency of Internet services by carefully studying the currently available infrastructure, optimizing it, and improving its performance. The focus is to optimize the performance of network functions deployed on commodity hardware, known as network function virtualization (NFV). The performance of NFV is one of the major sources of latency for Internet services. The first contribution is related to optimizing the software. This project began by investigating the possibility of superoptimizing virtualized network functions(VNFs). This began with a literature review of available superoptimization techniques, then one of the state-of-the-art superoptimization tools was selected to analyze the crucial metrics affecting application performance. The result of our analysis demonstrated that having better cache metrics could potentially improve the performance of all applications. The second contribution of this thesis employs the results of the first part by taking a step toward optimizing cache performance of time-critical NFV service chains. By doing so, we reduced the tail latencies of such systems running at 100Gbps. This is an important achievement as it increases the probability of realizing bounded and predictable latency for Internet services. / Tack vare den senaste tekniska utvecklingen inom beräkningar i molnet(“cloud computing”) används allt fler tillämpningar i molnlösningar. Flera avdessa moderna molnbaserade tillämpningar kräver korta svarstider är låga ochatt dessa ska vara förutsägbara och ligga inom givna gränser. Den nuvarandemolninfrastrukturen är dock otillräcklig eftersom den inte kan uppfylla dessa krav,på grund av olika typer av begränsningar i både hårdvara och mjukvara. I denna licentiatavhandling beskrivs försök att minska fördröjningen iinternettjänster genom att noggrant studera den nuvarande tillgängligainfrastrukturen, optimera den och förbättra dess prestanda. Fokus ligger påatt optimera prestanda för nätverksfunktioner som realiseras med hjälp avstandardhårdvara, känt som nätverksfunktionsvirtualisering (NFV). Prestanda hosNFV är en av de viktigaste källorna till fördröjning i internettjänster. Det första bidraget är relaterat till att optimera mjukvaran. Detta projektbörjade med att undersöka möjligheten att “superoptimera” virtualiseradenätverksfunktioner (VNF). Detta inleddes med en litteraturöversikt av tillgängligasuperoptimeringstekniker, och sedan valdes ett av de toppmodernasuperoptimeringsverktygen för att analysera de viktiga mätvärden som påverkartillämpningssprestanda. Resultatet av vår analys visade att bättre cache-mätningar potentiellt skulle kunna förbättra prestanda för alla tillämpningar. Det andra bidraget i denna avhandling utnyttjar resultaten från den förstadelen genom att ta ett steg mot att optimera cache-prestanda för tidskritiskakedjor av NFV-tjänster. Genom att göra så reducerade vi de långa fördröjningarnahos sådana system som kördes vid 100 Gbps. Detta är en viktig bedrift eftersomdetta ökar sannolikheten för att uppnå en begränsad och förutsägbar fördrörninghos internettjänster. / <p>QC 20190415</p> / Time-Critical Clouds / ULTRA

[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

Network coding was introduced as a means to increase throughput in communication networks when compared to routing. Network coding can be used not only to communicate messages from some nodes in the network to other nodes but are also useful when some nodes in a network are interested in computing some functions of information generated at some other nodes. Such a situation arises in sensor networks. In this work, we study three problems in network coding. First, we consider the functional source coding with side information problem wherein there is one source that generates a set of messages and one receiver which knows some functions of source messages and demands some other functions of source messages. Cognizant of the receiver's side information, the source aims to satisfy the demands of the receiver by making minimum number of coded transmissions over a noiseless channel. We use row-Latin rectangles to obtain optimal codes for a given functional source coding with side information problem. Next, we consider the multiple receiver extension of this problem, called the functional index coding problem, in which there are multiple receivers, each knowing and demanding disjoint sets of functions of source messages. The source broadcasts coded messages, called a functional index code, over a noiseless channel. For a given functional index coding problem, the restrictions the demands of the receivers pose on the code are represented using the generalized exclusive laws and it is shown that a code can be obtained using the confusion graph constructed using these laws. We present bounds on the size of an optimal code based on the parameters of the confusion graph. For the case of noisy broadcast channel, we provide a necessary and sufficient condition that a code must satisfy for correct decoding of desired functions at each receiver and obtain a lower bound on the length of an error-correcting functional index code. In the second problem, we explore relation between network function computation problems and functional index coding and Metroid representation problems. In a network computation problem, the demands of the sink nodes in a directed acyclic multichip network include functions of the source messages. We show that any network computation problem can be converted into a functional index coding problem and vice versa. We prove that a network code that satisfies all the sink demands in a network computation problem exists if and only if its corresponding functional index coding problem admits a functional index code of a specific length. Next, we establish a relation between network computation problems and representable mastoids. We show that a network computation problem in which the sinks demand linear functions of source messages admits a scalar linear solution if and only if it is matricidal with respect to a representable Metroid whose representation fulfils certain constraints dictated by the network computation problem. Finally, we study the usage of the sum-product (SP) algorithm for decoding network codes. Though lot of methods to obtain network codes exist, the decoding procedure and complexity have not received much attention. We propose a SP algorithm based decoder for network codes which can be used to decode both linear and nonlinear network codes. We pose the decoding problem at a sink node as a marginalize a product function (MPF) problem over the Boolean smearing and use the SP algorithm on a suitably constructed factor graph to perform decoding. We propose and demonstrate the usage of trace back to reduce the number of operations required to perform SP decoding. The computational complexity of performing SP decoding with and without trace back is obtained. For nonlinear network codes, we define fast decidability of a network code at sinks that demand all the source messages and identify a sufficient condition for the same. Next, for network function computation problems, we present an MPF formulation for function computation at a sink node and use the SP algorithm to obtain the value of the demanded function.