Integrated IT and SDN Orchestration of multi-domain multi-layer transport networks

Telecom operators networks' management and control remains partitioned by technology, equipment supplier and networking layer. In some segments, the network operations are highly costly due to the need of the individual, and even manual, configuration of the network equipment by highly specialized personnel. In multi-vendor networks, expensive and never ending integration processes between Network Management Systems (NMSs) and the rest of systems (OSSs, BSSs) is a common situation, due to lack of adoption of standard interfaces in the management systems of the different equipment suppliers. Moreover, the increasing impact of the new traffic flows introduced by the deployment of massive Data Centers (DCs) is also imposing new challenges that traditional networking is not ready to overcome. The Fifth Generation of Mobile Technology (5G) is also introducing stringent network requirements such as the need of connecting to the network billions of new devices in IoT paradigm, new ultra-low latency applications (i.e., remote surgery) and vehicular communications. All these new services, together with enhanced broadband network access, are supposed to be delivered over the same network infrastructure. In this PhD Thesis, an holistic view of Network and Cloud Computing resources, based on the recent innovations introduced by Software Defined Networking (SDN), is proposed as the solution for designing an end-to-end multi-layer, multi-technology and multi-domain cloud and transport network management architecture, capable to offer end-to-end services from the DC networks to customers access networks and the virtualization of network resources, allowing new ways of slicing the network resources for the forthcoming 5G deployments. The first contribution of this PhD Thesis deals with the design and validation of SDN based network orchestration architectures capable to improve the current solutions for the management and control of multi-layer, multi-domain backbone transport networks. These problems have been assessed and progressively solved by different control and management architectures which has been designed and evaluated in real evaluation environments. One of the major findings of this work has been the need of developed a common information model for transport network's management, capable to describe the resources and services of multilayer networks. In this line, the Control Orchestration Protocol (COP) has been proposed as a first contriution towards an standard management interface based on the main principles driven by SDN. Furthermore, this PhD Thesis introduces a novel architecture capable to coordinate the management of IT computing resources together with inter- and intra-DC networks. The provisioning and migration of virtual machines together with the dynamic reconfiguration of the network has been successfully demonstrated in a feasible timescale. Moreover, a resource optimization engine is introduced in the architecture to introduce optimization algorithms capable to solve allocation problems such the optimal deployment of Virtual Machine Graphs over different DCs locations minimizing the inter-DC network resources allocation. A baseline blocking probability results over different network loads are also presented. The third major contribution is the result of the previous two. With a converged cloud and network infrastructure controlled and operated jointly, the holistic view of the network allows the on-demand provisioning of network slices consisting of dedicated network and cloud resources over a distributed DC infrastructure interconnected by an optical transport network. The last chapters of this thesis discuss the management and orchestration of 5G slices based over the control and management components designed in the previous chapters. The design of one of the first network slicing architectures and the deployment of a 5G network slice in a real Testbed, is one of the major contributions of this PhD Thesis.La gestión y el control de las redes de los operadores de red (Telcos), todavía hoy, está segmentado por tecnología, por proveedor de equipamiento y por capa de red. En algunos segmentos (por ejemplo en IP) la operación de la red es tremendamente costosa, ya que en muchos casos aún se requiere con guración individual, e incluso manual, de los equipos por parte de personal altamente especializado. En redes con múltiples proveedores, los procesos de integración entre los sistemas de gestión de red (NMS) y el resto de sistemas (p. ej., OSS/BSS) son habitualmente largos y extremadamente costosos debido a la falta de adopción de interfaces estándar por parte de los diferentes proveedores de red. Además, el impacto creciente en las redes de transporte de los nuevos flujos de tráfico introducidos por el despliegue masivo de Data Centers (DC), introduce nuevos desafíos que las arquitecturas de gestión y control de las redes tradicionales no están preparadas para afrontar. La quinta generación de tecnología móvil (5G) introduce nuevos requisitos de red, como la necesidad de conectar a la red billones de dispositivos nuevos (Internet de las cosas - IoT), aplicaciones de ultra baja latencia (p. ej., cirugía a distancia) y las comunicaciones vehiculares. Todos estos servicios, junto con un acceso mejorado a la red de banda ancha, deberán ser proporcionados a través de la misma infraestructura de red. Esta tesis doctoral propone una visión holística de los recursos de red y cloud, basada en los principios introducidos por Software Defined Networking (SDN), como la solución para el diseño de una arquitectura de gestión extremo a extremo (E2E) para escenarios de red multi-capa y multi-dominio, capaz de ofrecer servicios de E2E, desde las redes intra-DC hasta las redes de acceso, y ofrecer ademas virtualización de los recursos de la red, permitiendo nuevas formas de segmentación en las redes de transporte y la infrastructura de cloud, para los próximos despliegues de 5G. La primera contribución de esta tesis consiste en la validación de arquitecturas de orquestración de red, basadas en SDN, para la gestión y control de redes de transporte troncales multi-dominio y multi-capa. Estos problemas (gestion de redes multi-capa y multi-dominio), han sido evaluados de manera incremental, mediante el diseño y la evaluación experimental, en entornos de pruebas reales, de diferentes arquitecturas de control y gestión. Uno de los principales hallazgos de este trabajo ha sido la necesidad de un modelo de información común para las interfaces de gestión entre entidades de control SDN. En esta línea, el Protocolo de Control Orchestration (COP) ha sido propuesto como interfaz de gestión de red estándar para redes SDN de transporte multi-capa. Además, en esta tesis presentamos una arquitectura capaz de coordinar la gestión de los recursos IT y red. La provisión y la migración de máquinas virtuales junto con la reconfiguración dinámica de la red, han sido demostradas con éxito en una escala de tiempo factible. Además, la arquitectura incorpora una plataforma para la ejecución de algoritmos de optimización de recursos capaces de resolver diferentes problemas de asignación, como el despliegue óptimo de Grafos de Máquinas Virtuales (VMG) en diferentes DCs que minimizan la asignación de recursos de red. Esta tesis propone una solución para este problema, que ha sido evaluada en terminos de probabilidad de bloqueo para diferentes cargas de red. La tercera contribución es el resultado de las dos anteriores. La arquitectura integrada de red y cloud presentada permite la creación bajo demanda de "network slices", que consisten en sub-conjuntos de recursos de red y cloud dedicados para diferentes clientes sobre una infraestructura común. El diseño de una de las primeras arquitecturas de "network slicing" y el despliegue de un "slice" de red 5G totalmente operativo en un Testbed real, es una de las principales contribuciones de esta tesis.La gestió i el control de les xarxes dels operadors de telecomunicacions (Telcos), encara avui, està segmentat per tecnologia, per proveïdors d’equipament i per capes de xarxa. En alguns segments (Per exemple en IP) l’operació de la xarxa és tremendament costosa, ja que en molts casos encara es requereix de configuració individual, i fins i tot manual, dels equips per part de personal altament especialitzat. En xarxes amb múltiples proveïdors, els processos d’integració entre els Sistemes de gestió de xarxa (NMS) i la resta de sistemes (per exemple, Sistemes de suport d’operacions - OSS i Sistemes de suport de negocis - BSS) són habitualment interminables i extremadament costosos a causa de la falta d’adopció d’interfícies estàndard per part dels diferents proveïdors de xarxa. A més, l’impacte creixent en les xarxes de transport dels nous fluxos de trànsit introduïts pel desplegament massius de Data Centers (DC), introdueix nous desafiaments que les arquitectures de gestió i control de les xarxes tradicionals que no estan llestes per afrontar. Per acabar de descriure el context, la cinquena generació de tecnologia mòbil (5G) també presenta nous requisits de xarxa altament exigents, com la necessitat de connectar a la xarxa milers de milions de dispositius nous, dins el context de l’Internet de les coses (IOT), o les noves aplicacions d’ultra baixa latència (com ara la cirurgia a distància) i les comunicacions vehiculars. Se suposa que tots aquests nous serveis, juntament amb l’accés millorat a la xarxa de banda ampla, es lliuraran a través de la mateixa infraestructura de xarxa. Aquesta tesi doctoral proposa una visió holística dels recursos de xarxa i cloud, basada en els principis introduïts per Software Defined Networking (SDN), com la solució per al disseny de una arquitectura de gestió extrem a extrem per a escenaris de xarxa multi-capa, multi-domini i consistents en múltiples tecnologies de transport. Aquesta arquitectura de gestió i control de xarxes transport i recursos IT, ha de ser capaç d’oferir serveis d’extrem a extrem, des de les xarxes intra-DC fins a les xarxes d’accés dels clients i oferir a més virtualització dels recursos de la xarxa, obrint la porta a noves formes de segmentació a les xarxes de transport i la infrastructura de cloud, pels propers desplegaments de 5G. La primera contribució d’aquesta tesi doctoral consisteix en la validació de diferents arquitectures d’orquestració de xarxa basades en SDN capaces de millorar les solucions existents per a la gestió i control de xarxes de transport troncals multi-domini i multicapa. Aquests problemes (gestió de xarxes multicapa i multi-domini), han estat avaluats de manera incremental, mitjançant el disseny i l’avaluació experimental, en entorns de proves reals, de diferents arquitectures de control i gestió. Un dels principals troballes d’aquest treball ha estat la necessitat de dissenyar un model d’informació comú per a les interfícies de gestió de xarxes, capaç de descriure els recursos i serveis de la xarxes transport multicapa. En aquesta línia, el Protocol de Control Orchestration (COP, en les seves sigles en anglès) ha estat proposat en aquesta Tesi, com una primera contribució cap a una interfície de gestió de xarxa estàndard basada en els principis bàsics de SDN. A més, en aquesta tesi presentem una arquitectura innovadora capaç de coordinar la gestió de els recursos IT juntament amb les xarxes inter i intra-DC. L’aprovisionament i la migració de màquines virtuals juntament amb la reconfiguració dinàmica de la xarxa, ha estat demostrat amb èxit en una escala de temps factible. A més, l’arquitectura incorpora una plataforma per a l’execució d’algorismes d’optimització de recursos, capaços de resoldre diferents problemes d’assignació, com el desplegament òptim de Grafs de Màquines Virtuals (VMG) en diferents ubicacions de DC que minimitzen la assignació de recursos de xarxa entre DC. També es presenta una solució bàsica per a aquest problema, així com els resultats de probabilitat de bloqueig per a diferents càrregues de xarxa. La tercera contribució principal és el resultat dels dos anteriors. Amb una infraestructura de xarxa i cloud convergent, controlada i operada de manera conjunta, la visió holística de la xarxa permet l’aprovisionament sota demanda de "network slices" que consisteixen en subconjunts de recursos d’xarxa i cloud, dedicats per a diferents clients, sobre una infraestructura de Data Centers distribuïda i interconnectada per una xarxa de transport òptica. Els últims capítols d’aquesta tesi tracten sobre la gestió i organització de "network slices" per a xarxes 5G en funció dels components de control i administració dissenyats i desenvolupats en els capítols anteriors. El disseny d’una de les primeres arquitectures de "network slicing" i el desplegament d’un "slice" de xarxa 5G totalment operatiu en un Testbed real, és una de les principals contribucions d’aquesta tesi.Postprint (published version

Bringing Order into Things Decentralized and Scalable Ledgering for the Internet-of-Things

The Internet-of-Things (IoT) is simultaneously the largest and the fastest growing distributed system known to date. With the expectation of 50 billion of devices coming online by 2020, far surpassing the size of the human population, problems related to scale, trustability and security are anticipated. Current IoT architectures are inherently flawed as they are centralized on the cloud and explore fragile trust-based relationships over a plethora of loosely integrated devices, leading to IoT platforms being non-robust for every party involved and unable to scale properly in the near future. The need for a new architecture that addresses these concerns is urgent as the IoT is progressively more ubiquitous, pervasive and demanding regarding the integration of devices and processing of data increasingly susceptible to reliability and security issues. In this thesis, we propose a decentralized ledgering solution for the IoT, leveraging a recent concept: blockchains. Rather than replacing the cloud, our solution presents a scalable and fault-tolerant middleware for recording transactions between peers, under verifiable and decentralized trustability assumptions and authentication guarantees for IoT devices, cloud services and users. Following on the emergent trend in modern IoT architectures, we leverage smart hubs as blockchain gateways, aggregating, pre-processing and forwarding small amounts of data and transactions in proximity conditions, that will be verified and processed as transactions in the blockchain. The proposed middleware acts as a secure ledger and establishes private channels between peers, requiring transactions in the blockchain to be signed using threshold signature schemes and grouporiented verification properties. The approach improves the decentralization and robustness characteristics under Byzantine fault-tolerance settings, while preserving the blockchain distributed nature

Managing the Transition from SNMP to NETCONF: Comparing Dual-Stack and Protocol Gateway Hybrid Approaches

As industries become increasingly automated and stressed to seek business advantages, they often have operational constraints that make modernization and security more challenging. Constraints exist such as low operating budgets, long operational lifetimes and infeasible network/device upgrade/modification paths. In order to bypass these constraints with minimal risk of disruption and perform ``no harm'', network administrators have come to rely on using dual-stack approaches, which allow legacy protocols to co-exist with modern ones. For example, if SNMP is required for managing legacy devices, and a newer protocol (NETCONF) is required for modern devices, then administrators simply modify firewall Access Control Lists (ACLs) to allow passage of both protocols. In today's networks, firewalls are ubiquitous, relatively inexpensive, and able to support multiple protocols (hence dual-stack) while providing network security. While investigating securing legacy devices in heterogeneous networks, it was determined that dual-stack firewall approaches do not provide adequate protection beyond layer three filtering of the IP stack. Therefore, the NETCONF/SNMP Protocol Gateway hybrid (NSPG) was developed as an alternative in environments where security is necessary, but legacy devices are infeasible to upgrade, replace, and modify. The NSPG allows network administrators to utilize only a single modern protocol (NETCONF) instead of both NETCONF and SNMP, and enforce additional security controls without modifying existing deployments. It has been demonstrated that legacy devices can be securely managed in a protocol-agnostic manner using low-cost commodity hardware (e.g., the RaspberryPi platform) with administrator-derived XML-based configuration policies

Large-Scale Client/Server Migration Methodology

The purpose of this dissertation is to explain how to migrate a medium-sized or large company to client/server computing. It draws heavily on the recent IBM Boca Raton migration experience. The client/server computing model is introduced and related, by a Business Reengineering Model, to the major trends that are affecting most businesses today, including business process reengineering, empowered teams, and quality management. A recommended information technology strategy is presented. A business case development approach, necessary to justify the large expenditures required for a client/server migration, is discussed. A five-phase migration management methodology is presented to explain how a business can be transformed from mid-range or mainframe-centric computing to client/server computing. Requirements definition, selection methodology, and development alternatives for client/server applications are presented. Applications are broadly categorized for use by individuals (personal applications) or teams. Client systems, server systems, and network infrastructures are described along with discussions of requirements definition, selection, installation, and support. The issues of user communication, education, and support with respect to a large client/server infrastructure are explored. Measurements for evaluation of a client/server computing environment are discussed with actual results achieved at the IBM Boca Raton site during the 1994 migration. The dissertation concludes with critical success factors for client/server computing investments and perspectives regarding future technology in each major area

A Heterogeneously Segmented Cache Architecture for a Packet Forwarding Engine

As network traffic continues to increase and with the requirement to process packets at line rates, high performance routers need to forward millions of packets every second. Even with an efficient lookup algorithm like the LC-trie, each packet needs upto 5 memory accesses. Earlier work shows that a single cache for the nodes of an LC-trie can reduce the number of external memory accesses. We observe that the locality characteristics of the level-one nodes of an LC-trie are significantly different from those of lower-level nodes. Hence, we propose a heterogeneously segmented cache architecture (HSCA) which uses separate caches for level-one and lower-level nodes each with carefully chosen sizes. We further improve the hit rate of the level-one nodes cache by introducing a weight-based replacement policy and an intelligent index bit selection scheme. To evaluate our cache scheme with realistic traces, we propose a synthetic trace generation method which emulates real traces and can generate traces with varying locality characteristics. The base HSCA scheme gives us upto 16% reduction in misses over the unified scheme. The optimizations further enhance this improvement to upto 25 % for core router traces.

A Heterogeneously Segmented Cache Architecture for a Packet Forwarding Engine

As network traffic continues to increase and with the requirement to process packets at line rates, high performance routers need to forward millions of packets every second. Even with an efficient lookup algorithm like the LC-trie, each packet needs upto 5 memory accesses. Earlier work shows that a single cache for the nodes of an LC-trie can reduce the number of external memory accesses. We observe that the locality characteristics of the level-one nodes of an LC-trie are significantly different from those of lower-level nodes. Hence, we propose a heterogeneously segmented cache architecture (HSCA) which uses separate caches for level-one and lower-level nodes each with carefully chosen sizes. We further improve the hit rate of the level-one nodes cache by introducing a weight-based replacement policy and an intelligent index bit selection scheme. To evaluate our cache scheme with realistic traces, we propose a synthetic trace generation method which emulates real traces and can generate traces with varying locality characteristics. The base HSCA scheme gives us upto 16% reduction in misses over the unified scheme. The optimizations further enhance this improvement to upto 25 % for core router traces.