Software-defined Networking (SDN) is an emerging trend in communication networks that facilitates decoupling the control and data plane of multilayer switches. A logically centralized controller hosted on a server configures the forwarding tables (flow tables) of switches in order to route the various data flows.  To implement SDN, OpenFlow technology has been adopted by packet switching vendors as it provides increased flexibility for the control and management of a packet switched domain. OpenFlow technology provides flow based switching that is controlled by a network management control application running in an OpenFlow controller. In this thesis work we investigate how an OpenFlow Controller communicates with a legacy network via the OSPF routing protocol, how the size of the OpenFlow network effects the resources (memory and CPU) of a legacy router to whom the controller communicates. Also we examine bandwidth utilization of the link (between the OpenFlow network and legacy router). The main goal of this thesis is to find methods to reduce the consumption of resources of a legacy router. This study shows that the size of OpenFlow network directly affects the usage of the link’s bandwidth, and the memory and CPU usage of a legacy router. Aggregated information from the OpenFlow controller which is sent towards the legacy router can reduce the utilization of these resources. Finally we proposed several algorithms and design models that can be implemented for route aggregation in Software-defined Networks.  Implementation of the solutions suggested in this thesis will allow automatic route aggregation in SDN. ISPs deploying SDN architecture could benefit from the proposed design models and route aggregation solution. / Software-definierade nätverk (SDN) är en framväxande trend i kommunikationsnät som underlättar frikoppling kontroll och uppgifter plan flerskiktade switchar. Ett logiskt centraliserad styrenhet på en server konfigurerar vidarebefordran tabeller (flödestabeller) av växlar för att dirigera de olika dataflöden. För att genomföra SDN har OpenFlow teknik har antagits av paketförmedlande leverantörer eftersom det ger ökad flexibilitet för kontroll och förvaltning av en påslagen paket domän. OpenFlow teknik ger flöde baserad omkoppling som styrs av ett nätverk ledningens kontroll som körs i en OpenFlow controller. I detta examensarbete undersöker vi hur en OpenFlow Controller kommunicerar med ett äldre nätverk via OSPF routing protokoll, hur storleken på OpenFlow nätverkseffekter de resurser (minne och CPU) av en äldre router till vilken styrenheten kommunicerar.  Också vi undersöker bandbreddsutnyttjandet av sambandet (mellan OpenFlow nätverket och äldre router). Det huvudsakliga målet med detta examensarbete är att hitta metoder för att minska konsumtionen av resurser från en äldre router. Denna studie visar att storleken på OpenFlow nätverk direkt påverkar användningen av länkens bandbredd och minne och CPU-användning av en äldre router. Samlad information från OpenFlow styrenhet som sändes mot äldre router kan minska utnyttjandet av dessa resurser. Slutligen föreslog vi flera algoritmer och modeller konstruktion som kan genomföras för route aggregation i Software Defined-nätverk. Genomförandet av de lösningar som föreslås i denna avhandling kommer att möjliggöra automatisk route aggregation i SDN. Internetleverantörer distribuerar SDN arkitektur kunde dra nytta av den föreslagna utformningen modeller och route aggregation lösning.

This master’s thesis explains why certain network services are difficult to provision and configure using IT automation and cloud orchestration software. An improvement is proposed and motivated. This proposed improvement enables network operators to define a set of data models describing how to provision and interconnect a set of Virtual Network Functions (VNFs) (and possibly existing physical network functions) to form networks. Moreover, the proposed solution enables network operators to change the configuration at runtime. The work can be seen as a step towards self managing and auto scaling networks. The proposed approach is compared to a well known cloud management system (OpenStack) in order to evaluate if the proposed approach decreases the amount of time needed for network operators to design network topologies and services containing VNFs. Data is collected through observations of network operators, interviews, and experiment. Analysis of this data shows that the proposed approach can decrease the amount of time required for network operators to design network topologies and services. This applies if the network operators are already acquainted with the data modeling language YANG. The amount of time required to provision VNFs so that they respond to connections can also be decreased using the proposed approach. The proposed approach does not offer as much functionality as OpenStack, as it is limited to VNF scenarios. / Denna masteruppsats förklarar varför vissa nätverkstjänster är svåra att skapa och konfigurera med IT-automationsverktyg och mjukvara för molnorkestrering.  En förbättring föreslås och motiveras. Den föreslagna förbättringen tillåter nätverksoperatörer att definiera en mängd datamodeller, för att beskriva hur Virtuella Nätverksfunktioner (VNF:er) skall instantieras och kopplas ihop till nätverkstjänster. Dessutom tillåter lösningen nätverksoperatörer att ändra konfiguration under tiden nätverken hanterar trafik.  Arbetet kan ses som ett steg mot självhanterande och automatiskt skalande nätverk. Den föreslagna lösningen jämförs med ett välkänt molnorkestreringsverktyg (OpenStack) för att utvärdera om den föreslagna lösningen sänker mängden tid som nätverksoperatörer behöver för att designa nätverkstopologier och tjänster som innehåller VNF:er. Data samlas in genom observationer av nätverksoperatörer, intervjuer, och experiment. Analys av datan visar att den föreslagna lösningen kan minska tiden som behövs för att designa nätverkstopologier och tjänster. Fallen där detta är applicerbart, är när VNF:er närvarar i nätverk. Dessa är enklare att skapa, konfigurera, och ändra under tiden de exekverar, med den föreslagna metoden. Detta kräver också att nätverksoperatören är bekant med datamodelleringsspråket YANG. Tiden det tar att provisionera VNF:er, tills dess att de svarar till anslutningar, kan sänkas med hjälp av den föreslagna metoden. Den förslagna metoden erbjuder väsentligt begränsad funktionalitet jämfört med OpenStack, den fokuserar på att hantera VNF:er.

Cette thèse démontre l'importance des informations réseau inter-couche pour les applications réseaux. Cette dissertation présente une nouvelle architecture de contrôle d'accès dans laquelle le contrôleur est mutualisé dans le Cloud. Cette architecture permet d'adresser un marché clé pour des clients ne pouvant acheter du matériel spécialisé. Plusieurs verrous techniques ont du être résolus pour pouvoir implémenter cette architecture, en effet les informations du réseau privé ne sont plus disponible au niveau du contrôleur ce qui l'empêche de correctement contrôler l'activité des utilisateurs. Une première implémentation est présentée dans le chapitre 2, elle utilise des équipements spécialisés capable d'interagir avec le contrôleur centralisé. Cette implémentation comportant des faiblesses, nous nous sommes intéressés à une approche par réseaux logiciels. Une solution innovante pour partager des informations inter-couche à l'extérieur d'un réseau SDN est présentée dans le chapitre 3. Elle permet d'intercepter et de modifier des flux de données utilisateurs à la volée afin de transmettre des informations à l'intérieur de la couche applicative. Cette solution a été implémentée dans le contrôleur OpenDaylight et montre des résultats très encourageants. Couplée au contrôleur centralisé, cette solution permet de fournir une solution complète de contrôle d'accès réseau qui est simple à déployer et configurer et extensible aisément. / This thesis presents the importance of cross-layer network information for network applications in the context of network access control. The dissertation exposes a novel architecture in which a network access controller is mutualized in the Cloud. This architecture allows to address a key market segment for clients unwilling to buy expensive hardware to control their network. Multiple challenges come into play when hosting the controller remotely. Indeed cross-layer information are no longer available which prevents the controller from correctly controlling users activity. A first implementation to share cross-layer information is presented in chapter 2. It leverages specialized session border controllers to send these data in the application protocol, here HTTP. Then chapter 3 presents an innovative solution for the cross-layering problem which allows to intrumentalize network flows with SDN protocols. The solution focuses on a web portal redirection but is extendable to any kind of protocols. The implementation permits to intercept and modify flows in order to input cross-layer data within another network protocol. This solution was implemented in the OpenDaylight OpenFlow controller and shows great results. The mutualized approach coupled with the SDN cross-layer framework allow to build flexible networks with almost no configuration of on-site equipments. The central network controller reduces the overal cost of the solution by being mutualized among multiple clients. Moreover, having the ability to intrumentalize network traffic in software allows to implement any kind of custom behavior on the runtime.

This dissertation aims to explore how one could leverage Software Defined Network (SDN) and Network Function Virtualization (NFV) principles in order to realize Service Function Chaining (SFC) in a network. SDN is a new networking paradigm, which makes a network programmable through the use of a software entity called SDN controller. NFV is intended to enable deployment of virtualized network functions, therefore replacing existing hardware solutions. SFC provides the ability to route user traffic to one or more network functions in an orderly manner. SFC will potentially enable many use cases such as data providers being able to dynamically steer user traffic through a set of network functions such as rewall and loadbalancer. This study is based on a set of goals. These goals evolve around the implementation of a prototype that will enable a SDN controller to steer user traffic through a series of virtualized network functions (VNFs). An important part of the prototype setup is a Network Management Software (NMS) named BECS, which is developed by Packetfront Software AB. BECS is acting as an orchestrator on the network and has complete awareness of all the network devices present on the network it manages. One of the main requirements of the prototype is to enable BECS to communicate with a SDN controller. Once that has been achieved, BECS could provide the necessary information that the controller needs in order to create and install a set of forwarding rules in the SDN enabled switches of the network. All those steps are necessary in order to achieve SFC. In this prototype, SFC is realized by demonstrating the user specific traffic steering through a set of VNFs in a specific order, based on control messages originated from BECS. Until now, network architecture has been limited to the capabilities of the actual hardware equipment. SDN and NFV help us to overcome this limitation. Information needs to be available anywhere and at any time, in a reliable and secure way. To ensure that, we propose a new scheme of network architecture through our prototype solution. This solution intends to give the ability to network managers to re-shape their networks based on their needs by the use of SFC. / Denna avhandling syftar till att undersöka hur man kan utnyttja principer för Software Defined Network (SDN) och Network Function Virtualization (NFV) för att förverkliga Service Function Chaining (SFC) i ett nätverk. SDN är en ny typ av nätverksparadigm som gör ett nätverk programmerbart genom användning av en programvaruenhet som kallas SDN controller. NFV syftar till att möjliggöra utbyggnaden av virtualiserade nätverksfunktioner och på så sätt ersätta befintliga hårdvarulösningar. SFC bidrar till en förmåga att dirigera trafiken till en eller flera nätverksfunktioner på ett ordnat sätt. SFC kommer potentiellt att möjliggöra många användningsområden, t.ex. uppgiftslämnare som dynamiskt kommer kunna styra användartrafik genom en uppsättning av nätverksfunktioner såsom firewall och loadbalancer. Studien är baserad på en uppsättning av mål. Dessa mål kretsar kring genomförandet av en prototyp som gör det möjligt för en SDN-styrenhet att styra användartrafik genom en serie av virtualiserade nätverksfunktioner (VNFs). En viktig del av prototypinstallationen ar en Network Management Software (NMS) som heter BECS, vilken är utvecklad av Packetfront Software AB. BECS agerar som en Orchestrator på nätet och har fullständig kännedom om alla nätverksenheter som finns i nätverket som den förvaltar. Ett av de viktigaste kraven for prototypen är att göra det möjligt for BECS att kommunicera med en SDN controller. När detta uppnåtts kunde BECS lämna nödvändiga uppgifter som styrenheten behöver for att kunna skapa och installera en uppsattning vidarebefordrade regler iSDN-aktiverade switchar pa natet. Alla dessa åtgarder är nödvändiga for att uppnå SFC. I denna prototyp realiseras SFC genom att påvisa den användarspecifika trafikstyrningen genom en uppsättning VNFs i en viss ordning, vilket baseras på styrmeddelanden som härstammar fran BECS. Fram till nu har nätverksarkitektur varit begränsad till förmågan hos den faktiska hårdvaruutrustningen. SDN och NFV hjalper oss att undvika denna begränsning. Information måste finnas tillgänglig överallt och när som helst på ett tillförlitligt och säkert sätt. For att säkerställa detta föreslår vi med hjälp av vår prototyplösning ett nytt system for nätverksarkitektur. Denna lösning har för avsikt att ge network managers en förmåga att omforma sina nät baserat på deras behov av SFC-anvandning.

The main aim of this work is to become familiar with the technology of software-defined networks and learn to use some of the tools to measure and simulate these networks.

By advancing technologies in both hardware and software, it is possible to support more complex applications. Wireless Sensor Networks (WSNs) comprised of tiny sensing devices with wireless radios are the key enablers for future Internet of Things(IoT) applications, where collecting measurements and delivering them to their destination is the most important task. In traditional sensor networks, sensor nodes were typically stationary and each node periodically measured and sent data to the next predefined router. However, in current applications, some nodes are expected to move. For instance, in health monitoring applications, where patients with sensors attached to their body are free to move in the hospital or their houses. Software Defined Networking (SDN) is a technique that was conventionally used in wired networks, and recently was used in some wireless networks, such as cellular and wireless local area networks. The idea of SDN is to provide more flexibility in the network by getting the advantage of re-programmability of the network devices during run-time. In networks based on SDN, the control plane is shifted from the infrastructure to a higher level in order to provide re-configuration. The controller decides on updating forwarding rules by getting some feedback from nodes in the network. In wireless sensor networks, the feedback may contain information related to the link quality and available resources such as battery level and the location of the sensor node (number of hops away from the sink). In this thesis, a study ofseveral relevant SDN-based architectures for wireless sensor networks is given, outlining the main advantages and disadvantages for each. In addition, some mobility solutions in sensor networks such as localization, routing and hand-off algorithms are explored. One of the drawbacks with SDN is that it was originally built for wired networks there experience with mobility does not exist. Thus the thesis considers the possibility to use SDN solutions in WSN were certain applications are in need of mobility. Finally, the thesis propose mobility solution for sensor networks that takes advantage of SDN and uses a handoff algorithm. In fact, the hand-off mechanism is achieved by means of control message exchanges that is supervised by the controller.

Context. In the present network inventive world, there is a quick expansion of switches and protocols, which are used to cope up with the increase in customer requirement in the networking. With increasing demand for higher bandwidths and lower latency and to meet these requirements new network paths are introduced. To reduce network load in present switching network, development of new innovative switching is required. These required results can be achieved by Software Define Network or Traditional layer-3 technologies.Objectives. In this thesis, the end to end (e2e) transmission performance of OpenFlow and Layer-3 switches and their dynamic characteristics are investigated using network simulation.Methods. To replicate real life network topology and evaluate e2e transmission performance, a simulation based test-bed is implemented for both OpenFlow switch and layer-3 switch. The test beds are implemented using Network Simulator-3 (NS3). A two-tire network topology is designed with specified components for performance evaluation.Results. The performance metrics like throughput, average delay, simulation time and Packet Delivery Ratio (PDR) are measured, results are analyzed statistically and are compared. The behavior of network traffic in both the topologies are understood using NS-3 and explained further in the thesis.Conclusions. The analytical and statistical results from simulation show that OpenFlow switching performs relatively better than layer-3 switching.

In-Band Network Telemetry (INT) is a new technique in the area of Software-defined networking (SDN) for monitoring SDN enabled networks. INT monitoring provides fine-grained INT data with less load on the control plane since monitoring is done directly at the data plane. The collected INT data is added as packet headers "In-band" at each INT device along the flow path. The INT data is later composed into telemetry packets which are sent to a collector that is responsible for processing the INT data. The collector of the INT data needs to have good performance since there is a large amount of data that has to be processed quickly. INTCollector, a high performance collector of INT data, is a response to this challenge. The performance of INTCollector is optimized by implementing critical parts in eXpress Data Path (XDP), enabling fast packet processing. INTCollector is, moreover, able to reduce processing of INT data and the need for storage space since it employs a strategy where only important INT data is collected, decided by an internal event detection mechanism.The event detection mechanism in INTCollector can however be offloaded to the INT device itself, with possible perfomance benefits for the collector. Programming Protocol-Independent Packet Processors (P4) opens up this possibility by providing a language for programming network devices. This thesis presents an implementation of INT in P4 with offloaded event detection. We use a programmable P4 testbed to perform an experimental evaluation, which reveal that offloading does indeed benefit INTCollector in terms of performance. Offloading also comes with the advantage of  allowing parameters of the event detection logic at the data plane to be accessible to the control plane.

A demanda de eficiência no gerenciamento das redes aumenta atualmente devido ao rápido desenvolvimento da computação em nuvem e a implantação em grande escala de centros de dados. O controle da infraestrutura deve ser capaz de classificar os diversos tipos de tráfego para aplicações diferentes, e prover o atendimento adequado no menor tempo possível. Porém, devido ao dinamismo da rede, nem sempre podem ser garantidos os requisitos mínimos necessários na Internet. Os mecanismos propostos para a engenharia de tráfego até hoje, são baseados em arquiteturas inflexíveis com a camada de controle e dados fortemente integrados. Isto dificulta um atendimento diferenciado adaptável aos diversos padrões de tráfego das aplicações modernas. Para enfrentar os problemas de flexibilidade das redes tradicionais, as Redes Definidas por Software, apresentam um paradigma inovador que separa as camadas de controle e encaminhamento de pacotes de forma a garantir a utilização eficiente dos recursos disponíveis, e ao mesmo tempo maior flexibilidade de implementação. Este paradigma permite conhecer o estado da rede e a sua topologia em tempo real, o que faz possível a reconfiguração de rotas e alocação de recursos de forma dinâmica. Esta dissertação apresenta um framework para engenharia de tráfego em SDN que utiliza a teoria matemática Network Calculus como ferramenta para subsidiar a caracterização e o policiamento de fluxos de pacotes. Através desta teoria, as decisões de encaminhamento e a distribuição do tráfego são baseadas não só por valores obtidos monitorando a rede, como também por projeções determinísticas que descrevem o comportamento do tráfego. Os resultados obtidos nos experimentos, comprovaram a eficiência no balanceamento de carga da rede em termos de atraso, demonstrando ganhos em termos de vazão do sistema e possibilitando a diminuição da porcentagem de perda de pacotes dos fluxos trafegados. O framework proposto visa contribuir na solução dos desafios relacionados a se estabelecer Engenharia de Tráfego para SDN com a especificação de mecanismos de gerenciamento adaptáveis as mudanças topológicas da rede, as diferentes características dos fluxos e que sejam capazes de distribuir de forma equilibrada o tráfego na rede. / The demand for network management efficiency is currently boosted by the rapid development of cloud computing and the large-scale deployment of data centers. Infrastructure control should be able to classify the various types of traffic for different applications, and provide adequate service in the shortest time possible. However, due to the dynamism of the network, the necessary minimum requirements on the Internet can not always be guaranteed. The proposed mechanisms for traffic engineering to date are based on inflexible architectures with the control and data layer strongly integrated. This hinders a differentiated service adaptable to the different traffic patterns of modern applications. To address the flexibility problems of traditional networks, Software Defined Networks presents an innovative paradigm that separates packet control and datapath layers to ensure the ecient use of available resources while providing greater deployment flexibility. This paradigm allows to know the state of the network and its topology in real time, which makes it possible to reconfigure routes and allocate resources dynamically. This work presents a framework for SDN traffic engineering that uses the mathematical theory Network Calculus as a tool to subsidize the characterization and policing of packet flows. Through this theory, routing decisions and traffic distribution are based not only on values obtained by monitoring the network, but also on deterministic projections of traffic behavior. The results obtained in the experiments, proved the efficiency in the load balancing of the network based on flow delay, demonstrating gains in terms of total system throughput and enabling the reduction of the percentage of packet loss of the traffic flows. The framework proposed aims to contribute to the solution of the challenges related to establishing Traffic Engineering for SDN with specification of management mechanisms, adaptables to the topological changes of the network, the different characteristics of the flows and capable of distribute in a balanced way the traffic in the network.

In this thesis, three key issues that restrict networks from scaling up so as to be able to cope with the rapid increase in traffic are investigated and series of approaches are proposed and tested for overcoming them. Firstly, scalability limitations owing to the use of a broadcast mechanism in one collision domain are discussed. To address this matter, servers under software-defined network architectures for eliminating discovery messages (SSED) are designed in this thesis and a backbone of floodless packets in an SDN LAN network is introduced. SSED has an innovative mechanism for defining the relationship between the servers and SDN architecture. Experimental results, after constructing and applying an authentic testbed, verify that SSED has the ability to improve upon the scalability of the traditional mechanism in terms of the number of switches and hosts. This is achieved by removing broadcast packets from the data and control planes as well as offering a better response time. Secondly, the scalability restrictions from using routers and the default gateway mechanism are explained. In this thesis, multiple distributed subnets using SDN architecture and servers to eliminate router devices and the default gateway mechanism (MSSERD) are introduced, designed and implemented as the general backbone for scalable multiple LAN-based networks. MSSERD's proposed components handle address resolution protocol (ARP) discovery packets and general IP packets across different subnets. Moreover, a general view of the network is provided through a multi-subnets discovery protocol (MDP). A 23 computers testbed is built and the results verify that MSSERD scales up the number of subnets more than traditional approaches, enhances the efficiency significantly, especially with high load, improves performance 2.3 times over legacy mechanisms and substantially reduces complexity. Finally, most of the available distributed-based architectures for different domains are reviewed and the aggregation discovery mechanism analysed to establish their impact on network scalability. Subsequently, a general distributed-centralised architecture with open-level control plane (OLC) architecture and a dynamic discovery hierarchical protocol (DHP) is introduced to provide better scalability in an SDN network. OLC can scale up the network with high performance even during high traffic.