21 research outputs found

    Congestion removal in the next generation internet

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    The ongoing development of new and demanding Internet applications requires the Internet to deliver better service levels that are significantly better than the best effort service that the Internet currently provides and was built for. These improved service levels include guaranteed delays, jitter and bandwidth. Through extensive research into Quality of Service and Differentiated Service (DiffServ) it has become possible to provide guaranteed services, however this turns out to be inadequate without the application of Traffic Engineering methodologies and principles. Traffic Engineering is an integral part of network operation. Its major goal is to deliver the best performance from an existing service provider's network resources and, at the same time, to enhance a customers' view of network performance. In this thesis, several different traffic engineering methods for optimising the operation of native IP and IP networks employing MPLS are proposed. A feature of these new methods is their fast run times and this opens the way to making them suitable for application in an online traffic engineering environment. For native IP networks running shortest path based routing protocols, we show that an LP-based optimisation based on the well known multi-commodity flow problem can be effective in removing network congestion. Having realised that Internet service providers are now moving towards migrating their networks to the use of MPLS, we have also formulated optimisation methods to traffic engineer MPLS networks by selecting suitable routing paths and utilising the feature of explicit routing contained in MPLS. Although MPLS is capable of delivering traffic engineering across different classes of traffic, network operators still prefer to rely on the proven and simple IP based routing protocols for best effort traffic and only use MPLS to route traffic requiring special forwarding treatment. Based on this fact, we propose a method that optimises the routing patterns applicable to different classes of traffic based on their bandwidth requirements. A traffic engineering comparison study that evaluates the performance of a neural network-based method for MPLS networks and LP-based weight setting approach for shortest path based networks has been performed using a well-known open source network simulator, called ns2. The comparative evaluation is based upon the packet loss probability. The final chapter of the thesis describes the software development of a network management application called OptiFlow which integrates techniques described in earlier chapters including the LP-based weight setting optimisation methodology; it also uses traffic matrix estimation techniques that are required as input to the weight setting models that have been devised. The motivation for developing OptiFlow was to provide a prototype set of tools that meet the congestion management needs of networking industries (ISPs and telecommunications companies - telcos)

    Path Protection Switching in Information Centric Networks (ICN)

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    Since its formation, the Internet has experienced tremendous growth, constantly increasing traffic and new applications, including voice and video. However, it still keeps its original architecture drafted almost 40 years ago built on the end-to-end principle; this has proven to be problematic when there are failures as routing convergence is slow for unicast networks and even slower for multicast which has to rely upon slow multicast routing as no protection switching exists for multicast. This thesis investigates protection in an alternative approach for network communication, namely information centric networking (ICN) using the architecture proposed by the PSIRP/PURSUIT projects. This uses Bloom Filters to allow both unicast and multicast forwarding. However, the PSIRP/PURSUIT ICN approach did not investigate protection switching and this problem forms the main aim of this thesis. The work builds on the research by Grover and Stamatelakis who introduced the concept of pre-configured protection p-cycles in 2000 for optical networks and, with modification, applicable to unicast IP or packet networks. This thesis shows how the p-cycle concept can be directly applied to packet networks that use PSIRP/PURSUIT ICN and extends the approach to encompass both unicast and multicast protection switching. Furthermore, it shows how the chosen p-cycles can be optimised to reduce the redundancy overhead introduced by the protection mechanism. The work evaluates the approach from two aspects, the first is how the proposed approach compares to existing switching state and traffic in an MPLS multicast architecture. The second considers the redundancy overhead in three known network topologies for synthetic traffic matrices. The thesis is the first work to demonstrate the efficiency of Bloom filter based switching for multicast (and unicast) protection switching

    Application of service composition mechanisms to Future Networks architectures and Smart Grids

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    Aquesta tesi gira entorn de la hip貌tesi de la metodologia i mecanismes de composici贸 de serveis i com es poden aplicar a diferents camps d'aplicaci贸 per a orquestrar de manera eficient comunicacions i processos flexibles i sensibles al context. M茅s concretament, se centra en dos camps d'aplicaci贸: la distribuci贸 eficient i sensible al context de contingut multim猫dia i els serveis d'una xarxa el猫ctrica intel路ligent. En aquest 煤ltim camp es centra en la gesti贸 de la infraestructura, cap a la definici贸 d'una Software Defined Utility (SDU), que proposa una nova manera de gestionar la Smart Grid amb un enfocament basat en programari, que permeti un funcionament molt m茅s flexible de la infraestructura de xarxa el猫ctrica. Per tant, revisa el context, els requisits i els reptes, aix铆 com els enfocaments de la composici贸 de serveis per a aquests camps. Fa especial 猫mfasi en la combinaci贸 de la composici贸 de serveis amb arquitectures Future Network (FN), presentant una proposta de FN orientada a serveis per crear comunicacions adaptades i sota demanda. Tamb茅 es presenten metodologies i mecanismes de composici贸 de serveis per operar sobre aquesta arquitectura, i posteriorment, es proposa el seu 煤s (en conjunci贸 o no amb l'arquitectura FN) en els dos camps d'estudi. Finalment, es presenta la investigaci贸 i desenvolupament realitzat en l'脿mbit de les xarxes intel路ligents, proposant diverses parts de la infraestructura SDU amb exemples d'aplicaci贸 de composici贸 de serveis per dissenyar seguretat din脿mica i flexible o l'orquestraci贸 i gesti贸 de serveis i recursos dins la infraestructura de l'empresa el猫ctrica.Esta tesis gira en torno a la hip贸tesis de la metodolog铆a y mecanismos de composici贸n de servicios y c贸mo se pueden aplicar a diferentes campos de aplicaci贸n para orquestar de manera eficiente comunicaciones y procesos flexibles y sensibles al contexto. M谩s concretamente, se centra en dos campos de aplicaci贸n: la distribuci贸n eficiente y sensible al contexto de contenido multimedia y los servicios de una red el茅ctrica inteligente. En este 煤ltimo campo se centra en la gesti贸n de la infraestructura, hacia la definici贸n de una Software Defined Utility (SDU), que propone una nueva forma de gestionar la Smart Grid con un enfoque basado en software, que permita un funcionamiento mucho m谩s flexible de la infraestructura de red el茅ctrica. Por lo tanto, revisa el contexto, los requisitos y los retos, as铆 como los enfoques de la composici贸n de servicios para estos campos. Hace especial hincapi茅 en la combinaci贸n de la composici贸n de servicios con arquitecturas Future Network (FN), presentando una propuesta de FN orientada a servicios para crear comunicaciones adaptadas y bajo demanda. Tambi茅n se presentan metodolog铆as y mecanismos de composici贸n de servicios para operar sobre esta arquitectura, y posteriormente, se propone su uso (en conjunci贸n o no con la arquitectura FN) en los dos campos de estudio. Por 煤ltimo, se presenta la investigaci贸n y desarrollo realizado en el 谩mbito de las redes inteligentes, proponiendo varias partes de la infraestructura SDU con ejemplos de aplicaci贸n de composici贸n de servicios para dise帽ar seguridad din谩mica y flexible o la orquestaci贸n y gesti贸n de servicios y recursos dentro de la infraestructura de la empresa el茅ctrica.This thesis revolves around the hypothesis the service composition methodology and mechanisms and how they can be applied to different fields of application in order to efficiently orchestrate flexible and context-aware communications and processes. More concretely, it focuses on two fields of application that are the context-aware media distribution and smart grid services and infrastructure management, towards a definition of a Software-Defined Utility (SDU), which proposes a new way of managing the Smart Grid following a software-based approach that enable a much more flexible operation of the power infrastructure. Hence, it reviews the context, requirements and challenges of these fields, as well as the service composition approaches. It makes special emphasis on the combination of service composition with Future Network (FN) architectures, presenting a service-oriented FN proposal for creating context-aware on-demand communication services. Service composition methodology and mechanisms are also presented in order to operate over this architecture, and afterwards, proposed for their usage (in conjunction or not with the FN architecture) in the deployment of context-aware media distribution and Smart Grids. Finally, the research and development done in the field of Smart Grids is depicted, proposing several parts of the SDU infrastructure, with examples of service composition application for designing dynamic and flexible security for smart metering or the orchestration and management of services and data resources within the utility infrastructure
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