Транспортні мережі на основі технології MPLS, принципи, перспективи розвитку

Мета роботи – дослідження транспортних мереж на основі технології MPLS. Аналіз напрямків адаптації технології MPLS для досягнення відповідності вимогам транспортних мереж. У даній роботі розглядається транспортна мережа як невід’ємна частина телекомунікаційної системи, аналізуються технічні принципи функціювання мереж MPLS, проводиться огляд основних технічних принципів транспортних мереж MPLS TP та їх відмінностей від принципів MPLS, аналізується питання моніторингу і керування мережами MPLS TP та питання щодо напрямку подальшого розвитку мереж MPLS TP, зокрема, переходу до технології GMPLS.The purpose of the work is to study transport networks based on MPLS technology. Analysis of directions of MPLS technology adaptation to achieve compliance with the requirements of transport networks. This paper considers transport network as an integral part of telecommunication system, analyzes technical principles of MPLS networks operation, reviews main technical principles of MPLS TP transport networks and their differences from MPLS principles, analyzes the issue of monitoring and management of MPLS TP networks and the direction of further development of MPLS TP networks, in particular, the transition to GMPLS technology

Enhanced connectivity in wireless mobile programmable networks

Mención Interancional en el título de doctorThe architecture of current operator infrastructures is being challenged by the non-stop growing demand of data hungry services appearing every day. While currently deployed operator networks have been able to cope with traffic demands so far, the architectures for the 5th generation of mobile networks (5G) are expected to support unprecedented traffic loads while decreasing costs associated with the network deployment and operations. Indeed, the forthcoming set of 5G standards will bring programmability and flexibility to levels never seen before. This has required introducing changes in the architecture of mobile networks, enabling different features such as the split of control and data planes, as required to support rapid programming of heterogeneous data planes. Network softwarisation is hence seen as a key enabler to cope with such network evolution, as it permits controlling all networking functions through (re)programming, thus providing higher flexibility to meet heterogeneous requirements while keeping deployment and operational costs low. A great diversity in terms of traffic patterns, multi-tenancy, heterogeneous and stringent traffic requirements is therefore expected in 5G networks. Software Defined Networking (SDN) and Network Function Virtualisation (NFV) have emerged as a basic tool-set for operators to manage their infrastructure with increased flexibility and reduced costs. As a result, new 5G services can now be envisioned and quickly programmed and provisioned in response to user and market necessities, imposing a paradigm shift in the services design. However, such flexibility requires the 5G transport network to undergo a profound transformation, evolving from a static connectivity substrate into a service-oriented infrastructure capable of accommodating the various 5G services, including Ultra-Reliable and Low Latency Communications (URLLC). Moreover, to achieve the desired flexibility and cost reduction, one promising approach is to leverage virtualisation technologies to dynamically host contents, services, and applications closer to the users so as to offload the core network and reduce the communication delay. This thesis tackles the above challengeswhicharedetailedinthefollowing. A common characteristic of the 5G servicesistheubiquityandthealmostpermanent connection that is required from the mobile network. This really imposes a challenge in thesignallingproceduresprovidedtogettrack of the users and to guarantee session continuity. The mobility management mechanisms will hence play a central role in the 5G networks because of the always-on connectivity demand. Distributed Mobility Management (DMM) helps going towards this direction, by flattening the network, hence improving its scalability,andenablinglocalaccesstotheInternet and other communication services, like mobile-edge clouds. Simultaneously, SDN opens up the possibility of running a multitude of intelligent and advanced applications for network optimisation purposes in a centralised network controller. The combination of DMM architectural principles with SDN management appears as a powerful tool for operators to cope with the management and data burden expected in 5G networks. To meet the future mobile user demand at a reduced cost, operators are also looking at solutions such as C-RAN and different functional splits to decrease the cost of deploying and maintaining cell sites. The increasing stress on mobile radio access performance in a context of declining revenues for operators is hence requiring the evolution of backhaul and fronthaul transport networks, which currently work decoupled. The heterogeneity of the nodes and transmisión technologies inter-connecting the fronthaul and backhaul segments makes the network quite complex, costly and inefficient to manage flexibly and dynamically. Indeed, the use of heterogeneous technologies forces operators to manage two physically separated networks, one for backhaul and one forfronthaul. In order to meet 5G requirements in a costeffective manner, a unified 5G transport network that unifies the data, control, and management planes is hence required. Such an integrated fronthaul/backhaul transport network, denoted as crosshaul, will hence carry both fronthaul and backhaul traffic operating over heterogeneous data plane technologies, which are software-controlled so as to adapt to the fluctuating capacity demand of the 5G air interfaces. Moreover, 5G transport networks will need to accommodate a wide spectrum of services on top of the same physical infrastructure. To that end, network slicing is seen as a suitable candidate for providing the necessary Quality of Service (QoS). Traffic differentiation is usually enforced at the border of the network in order to ensure a proper forwarding of the traffic according to its class through the backbone. With network slicing, the traffic may now traverse many slice edges where the traffic policy needs to be enforced, discriminated and ensured, according to the service and tenants needs. However, the very basic nature that makes this efficient management and operation possible in a flexible way – the logical centralisation – poses important challenges due to the lack of proper monitoring tools, suited for SDN-based architectures. In order to take timely and right decisions while operating a network, centralised intelligence applications need to be fed with a continuous stream of up-to-date network statistics. However, this is not feasible with current SDN solutions due to scalability and accuracy issues. Therefore, an adaptive telemetry system is required so as to support the diversity of 5G services and their stringent traffic requirements. The path towards 5G wireless networks alsopresentsacleartrendofcarryingoutcomputations close to end users. Indeed, pushing contents, applications, and network functios closer to end users is necessary to cope with thehugedatavolumeandlowlatencyrequired in future 5G networks. Edge and fog frameworks have emerged recently to address this challenge. Whilst the edge framework was more infrastructure-focused and more mobile operator-oriented, the fog was more pervasive and included any node (stationary or mobile), including terminal devices. By further utilising pervasive computational resources in proximity to users, edge and fog can be merged to construct a computing platform, which can also be used as a common stage for multiple radio access technologies (RATs) to share their information, hence opening a new dimension of multi-RAT integration.La arquitectura de las infraestructuras actuales de los operadores está siendo desafiada por la demanda creciente e incesante de servicios con un elevado consumo de datos que aparecen todos los días. Mientras que las redes de operadores implementadas actualmente han sido capaces de lidiar con las demandas de tráfico hasta ahora, se espera que las arquitecturas de la quinta generación de redes móviles (5G) soporten cargas de tráfico sin precedentes a la vez que disminuyen los costes asociados a la implementación y operaciones de la red. De hecho, el próximo conjunto de estándares 5G traerá la programabilidad y flexibilidad a niveles nunca antes vistos. Esto ha requerido la introducción de cambios en la arquitectura de las redes móviles, lo que permite diferentes funciones, como la división de los planos de control y de datos, según sea necesario para soportar una programación rápida de planos de datos heterogéneos. La softwarisación de red se considera una herramienta clave para hacer frente a dicha evolución de red, ya que proporciona la capacidad de controlar todas las funciones de red mediante (re)programación, proporcionando así una mayor flexibilidad para cumplir requisitos heterogéneos mientras se mantienen bajos los costes operativos y de implementación. Por lo tanto, se espera una gran diversidad en términos de patrones de tráfico, multi-tenancy, requisitos de tráfico heterogéneos y estrictos en las redes 5G. Software Defined Networking (SDN) y Network Function Virtualisation (NFV) se han convertido en un conjunto de herramientas básicas para que los operadores administren su infraestructura con mayor flexibilidad y menores costes. Como resultado, los nuevos servicios 5G ahora pueden planificarse, programarse y aprovisionarse rápidamente en respuesta a las necesidades de los usuarios y del mercado, imponiendo un cambio de paradigma en el diseño de los servicios. Sin embargo, dicha flexibilidad requiere que la red de transporte 5G experimente una transformación profunda, que evoluciona de un sustrato de conectividad estática a una infraestructura orientada a servicios capaz de acomodar los diversos servicios 5G, incluso Ultra-Reliable and Low Latency Communications (URLLC). Además, para lograr la flexibilidad y la reducción de costes deseadas, un enfoque prometedores aprovechar las tecnologías de virtualización para alojar dinámicamente los contenidos, servicios y aplicaciones más cerca de los usuarios para descargar la red central y reducir la latencia. Esta tesis aborda los desafíos anteriores que se detallan a continuación. Una característica común de los servicios 5G es la ubicuidad y la conexión casi permanente que se requiere para la red móvil. Esto impone un desafío en los procedimientos de señalización proporcionados para hacer un seguimiento de los usuarios y garantizar la continuidad de la sesión. Por lo tanto, los mecanismos de gestión de la movilidad desempeñarán un papel central en las redes 5G debido a la demanda de conectividad siempre activa. Distributed Mobility Management (DMM) ayuda a ir en esta dirección, al aplanar la red, lo que mejora su escalabilidad y permite el acceso local a Internet y a otros servicios de comunicaciones, como recursos en “nubes” situadas en el borde de la red móvil. Al mismo tiempo, SDN abre la posibilidad de ejecutar una multitud de aplicaciones inteligentes y avanzadas para optimizar la red en un controlador de red centralizado. La combinación de los principios arquitectónicos DMM con SDN aparece como una poderosa herramienta para que los operadores puedan hacer frente a la carga de administración y datos que se espera en las redes 5G. Para satisfacer la demanda futura de usuarios móviles a un coste reducido, los operadores también están buscando soluciones tales como C-RAN y diferentes divisiones funcionales para disminuir el coste de implementación y mantenimiento de emplazamientos celulares. El creciente estrés en el rendimiento del acceso a la radio móvil en un contexto de menores ingresos para los operadores requiere, por lo tanto, la evolución de las redes de transporte de backhaul y fronthaul, que actualmente funcionan disociadas. La heterogeneidad de los nodos y las tecnologías de transmisión que interconectan los segmentos de fronthaul y backhaul hacen que la red sea bastante compleja, costosa e ineficiente para gestionar de manera flexible y dinámica. De hecho, el uso de tecnologías heterogéneas obliga a los operadores a gestionar dos redes separadas físicamente, una para la red de backhaul y otra para el fronthaul. Para cumplir con los requisitos de 5G de manera rentable, se requiere una red de transporte única 5G que unifique los planos de control, datos y de gestión. Dicha red de transporte fronthaul/backhaul integrada, denominada “crosshaul”, transportará tráfico de fronthaul y backhaul operando sobre tecnologías heterogéneas de plano de datos, que están controladas por software para adaptarse a la demanda de capacidad fluctuante de las interfaces radio 5G. Además, las redes de transporte 5G necesitarán acomodar un amplio espectro de servicios sobre la misma infraestructura física y el network slicing se considera un candidato adecuado para proporcionar la calidad de servicio necesario. La diferenciación del tráfico generalmente se aplica en el borde de la red para garantizar un reenvío adecuado del tráfico según su clase a través de la red troncal. Con el networkslicing, el tráfico ahora puede atravesar muchos fronteras entre “network slices” donde la política de tráfico debe aplicarse, discriminarse y garantizarse, de acuerdo con las necesidades del servicio y de los usuarios. Sin embargo, el principio básico que hace posible esta gestión y operación eficientes de forma flexible – la centralización lógica – plantea importantes desafíos debido a la falta de herramientas de supervisión necesarias para las arquitecturas basadas en SDN. Para tomar decisiones oportunas y correctas mientras se opera una red, las aplicaciones de inteligencia centralizada necesitan alimentarse con un flujo continuo de estadísticas de red actualizadas. Sin embargo, esto no es factible con las soluciones SDN actuales debido a problemas de escalabilidad y falta de precisión. Por lo tanto, se requiere un sistema de telemetría adaptable para respaldar la diversidad de los servicios 5G y sus estrictos requisitos de tráfico. El camino hacia las redes inalámbricas 5G también presenta una tendencia clara de realizar acciones cerca de los usuarios finales. De hecho, acercar los contenidos, las aplicaciones y las funciones de red a los usuarios finales es necesario para hacer frente al enorme volumen de datos y la baja latencia requerida en las futuras redes 5G. Los paradigmas de “edge” y “fog” han surgido recientemente para abordar este desafío. Mientras que el edge está más centrado en la infraestructura y más orientado al operador móvil, el fog es más ubicuo e incluye cualquier nodo (fijo o móvil), incluidos los dispositivos finales. Al utilizar recursos de computación de propósito general en las proximidades de los usuarios, el edge y el fog pueden combinarse para construir una plataforma de computación, que también se puede utilizar para compartir información entre múltiples tecnologías de acceso radio (RAT) y, por lo tanto, abre una nueva dimensión de la integración multi-RAT.Programa Oficial de Doctorado en Ingeniería TelemáticaPresidente: Carla Fabiana Chiasserini.- Secretario: Vincenzo Mancuso.- Vocal: Diego Rafael López Garcí

Resilient and Scalable Forwarding for Software-Defined Networks with P4-Programmable Switches

Traditional networking devices support only fixed features and limited configurability. Network softwarization leverages programmable software and hardware platforms to remove those limitations. In this context the concept of programmable data planes allows directly to program the packet processing pipeline of networking devices and create custom control plane algorithms. This flexibility enables the design of novel networking mechanisms where the status quo struggles to meet high demands of next-generation networks like 5G, Internet of Things, cloud computing, and industry 4.0. P4 is the most popular technology to implement programmable data planes. However, programmable data planes, and in particular, the P4 technology, emerged only recently. Thus, P4 support for some well-established networking concepts is still lacking and several issues remain unsolved due to the different characteristics of programmable data planes in comparison to traditional networking. The research of this thesis focuses on two open issues of programmable data planes. First, it develops resilient and efficient forwarding mechanisms for the P4 data plane as there are no satisfying state of the art best practices yet. Second, it enables BIER in high-performance P4 data planes. BIER is a novel, scalable, and efficient transport mechanism for IP multicast traffic which has only very limited support of high-performance forwarding platforms yet. The main results of this thesis are published as 8 peer-reviewed and one post-publication peer-reviewed publication. The results cover the development of suitable resilience mechanisms for P4 data planes, the development and implementation of resilient BIER forwarding in P4, and the extensive evaluations of all developed and implemented mechanisms. Furthermore, the results contain a comprehensive P4 literature study. Two more peer-reviewed papers contain additional content that is not directly related to the main results. They implement congestion avoidance mechanisms in P4 and develop a scheduling concept to find cost-optimized load schedules based on day-ahead forecasts

Gestão integrada de cloud usando redes definidas por software

Mestrado em Engenharia de Computadores e TelemáticaNestes últimos anos tem-se vindo a registar um grande aumento no número de dispositivos ligados à Internet a partir de praticamente qualquer lugar. Assim, para manter-se par com a procura, os Internet Providers têm de melhorar sua rede através da aquisição de mais dispositivos de rede, o que por sua vez aumenta o custo da infra-estrutura. Além disso, isso dificulta ainda mais a gestão das redes devido à sua abordagem centrada no hardware que requer a configuração manual de cada um dos dispositivos de rede. Uma mudança no paradigma atual tem sido estudado e evoluindo ao longo de décadas, mostrando, nos últimos anos, que ele pode realmente ser a futura direção para a rede. SDN é um novo paradigma de rede que facilita a gestão da mesma ao permitir que esta se torne programável. Isso é feito principalmente através da separação dos planos de dados e controlo e também através da criação de abstrações que tornam a rede mais flexível e escalável. O que por sua vez, permite a inovação e gestão mais simples de redes de data center em ambientes de cloud. O objetivo principal desta dissertação é implementar e avaliar uma solução que facilita a gestão, em ambientes de data center, usando este novo paradigma, SDN. Ela fornece configuração transparente e automática da rede subjacente, a fim de permitir a comunicação entre os nós com requisitos de largura de banda especificados. Além disso, também realiza a monitorização de balanceamento de carga para optimizar o uso de tráfego na rede. Esta dissertação apresenta a solução desenvolvida que utiliza um controlador de SDN e OpenvSwitch. A solução faz uso de ambos os protocolos OpenFlow e OVSDB, bem como os módulos do controlador OpenDaylight. A interacção com o controlador é realizada através do uso do REST APIs fornecidas pelo controlador acima mencionado. Durante a fase de avaliação, vários cenários de teste foram executados a fim de avaliar a correção e o desempenho do sistema que interage com a rede. A aplicação comportou-se razoavelmente bem por ser capaz de aplicar a largura de banda especificada on-demand (QoS) de uma maneira simples e sem falhas. Do mesmo modo, o balanceamento de carga foi também aplicado com sucesso, sem perder a comunicação entre os nós. Tudo isto foi realizado com overhead moderado (em termos de tempo de instalação e da quantidade de dados enviados para gerir a rede). Em conclusão, a solução mostra-se promissora pela sua facilidade na gestão de redes em data centers.These past few years we have been experiencing a large increase in the number of devices connected to the Internet from almost anywhere. Thus, to keep up with the demand, Service Providers have to upgrade their network by acquiring more network devices, which greatly increases the infrastructure’s cost. In addition, this hampers even more the management of the networks due to their hardware centric approach which requires manual configuration of each of the network devices. A change in the current paradigm has been studied and evolving for decades, showing, in the last years, that it can actually be the future direction for networking. SDN is a modern networking paradigm that eases network management by enable the network to be programmable. This is done mainly through the separation of data and control planes and also through the creation of abstractions that make the network more flexible and scalable. Which, in turn enables innovation and simpler management to data center networks in cloud environments. The main objective of this dissertation is to implement and evaluate a solution that eases the management in data center environments using this new paradigm, SDN. It provides seamless and automatic configuration of the underlying network in order to allow communication between nodes with on-demand bandwidth requirements. In addition, it also performs load balance monitoring to optimize the traffic usage on the network. This dissertation presents the developed solution which uses a SDN controller and OpenvSwitch. The solution makes use of both OpenFlow and OVSDB protocols as well as OpenDaylight controller’s modules. The interaction with the controller is performed through the use of the REST APIs provided by the above mentioned controller. During the evaluation stage, several test scenarios were executed in order to evaluate the correctness and performance of the system interacting with the network. The application behaved reasonably well by being able to apply the specified bandwidth on-demand (QoS) in a simple manner without flaws. Similarly, the load balance was also successfully applied without loosing communication between the hosts. All this was accomplished with moderate overhead (in terms of time of installation and quantity of data sent to manage the network). In conclusion, the solution shows to be promising for the ease of management in data center networks

Monitoring and orchestration of network slices for 5G Networks

Mención Internacional en el título de doctorEste trabajo se ha realizado bajo la ayuda concedida por la Comunidad de Madrid en la Convocatoria de 2017 de Ayudas para la Realización de Doctorados Industriales en la Comunidad de Madrid (Orden 3109/2017, de 29 de agosto), con referencia IND2017/TIC-7732. This work was partly funded by the European Commission under the European Union’s Horizon 2020 program - grant agreement number 815074 (5G EVE project). The Ph.D thesis solely reflects the views of the author. The Commission is not responsible for the contents of this Ph.D thesis or any use made thereof.Programa de Doctorado en Ingeniería Telemática por la Universidad Carlos III de MadridPresidente: Antonio de la Oliva Delgado.- Secretaria: Elisa Rojas Sánchez.- Vocal: David Manuel Gutiérrez Estéve