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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Granskning och optimering av data- och IP-telefoninätverk

Eriksson, Jhonny, Karlsson, Joel January 2010 (has links)
<p>The company Västra Mälardalens Kommunalförbund, VMKF, wishes to revise and optimize their present data and IP-telephony network as of today consists of the three municipalities Köping, Arboga and Kungsör. As a municipal corporation, they seek consultation regarding internal as well as external review and investigation of the main structure of the network, its functionality and safety. By today’s increasing demands of Internet accessibility, availability of services and security far more extends the requirement of a complete network design. The foundation of networking rests on the balance between each of these necessities. Therefore, it is of grave importance to optimize a network design, use of hardware and to minimize the administrative overhead. In particular, when the municipality is short of resources and time means money. By letting an impartial investigation of the network act as a starting point it was established that several improvement could be applied. Among these a reconstructed and improved network topology that includes subjects as routing, switching, safety and security, quality of service and technical administrative overhead and the implementation of a real time monitoring of network bandwidth consumption.</p> / <p>Företaget Västra Mälardalens Kommunalförbund, VMKF, har önskemål om att granska och optimera deras befintliga data- och IP-telefoninätverk som i dagsläget spänner över de tre kommunerna Köping, Arboga och Kungsör. Som ett kommunalägt företag önskar de konsultation rörande intern såväl som extern granskning och optimering av huvuddelen av nätverkets funktionalitet samt säkerhet. I och med dagens ökade Internetanvändning och funktionalitetsbehov ställs allt högre krav på tillgänglighet, säkerhet och användarvänlighet. Nätverksteknik bygger mycket på balansen mellan dessa tre punkter. Därför gäller det att optimera nätverkets design, hårdvaruanvändning och att minimera administrativa laster. Detta i synnerhet då kommunens resurser är knappa och då tid i dagens samhälle innebär pengar. Genom att låta en granskning över nätverket som det ser ut i dag ligga till grund konstaterades att flertalet förbättringsmöjligheter kunde genomföras. Bland dessa återfinns en omstrukturerad nätverksdesign som innefattar routing, switching, säkerhet, QoS och teknisk administration samt implementeringen av en realtidsövervakning av bandbreddsanvändning.</p>
42

Emulation of IP Core Network for Testing of the Serving GRPS Support Node (SGSN) Routing Application

Torkaman, Hossein January 2009 (has links)
<p>This thesis aims to investigate a method and tool for emulation of the General Packet Radio Service (GPRS) core network needed as an environment to test the routing functionality. GPRS is the most widely adopted mobile packet data delivery technology in the world. It utilizes an Intranet Protocol (IP)-based core network and involves significant changes to the way the Global System for Mobile communications (GSM) air interface is structured. It also forms the basis of the future structure of mobile network transmission and switching.</p><p>The Serving GPRS Support Node (SGSN) is the most fundamental node in GPRS. Ericsson produces and manages an increasing number of SGSN nodes in the world. One of main functionalities of SGSN node is to forward IP packets according to the destination address in the IP header on IP core network.</p><p>In each new release of SGSN, or when implementation or upgrades have been done on routing application on SGSN, design and test engineers at Ericsson need to emulate the IP core network. This must be done with use of many routers to generate huge amounts of data that can simulate the real world IP core network.</p><p>The major goal of this thesis was to analyze and verifying the use of a suitable and economical solution to emulating IP Core Network of the GPRS system for testing of different functionality of the routing application running in SGSN , instead of building up a physical Core Network with different infrastructure and many routers.</p><p>The method chosen for emulating the IP core network with many routers, and investigated in the thesis, is based on a Cisco simulator called “Dynamips”, which runs many actual Cisco Internetwork Operating Systems (IOS) with many different models of Cisco products in a virtual environment on Windows or Linux platforms. With this simulator, engineers at Ericsson will be able to use this simulator to emulate IP core network easily and efficiently to accomplish system test cases.</p><p>A conclusion of this work is that Dynamips could be used to emulate many complicated IP core network scenarios, with many routers to generate huge amounts of data to simulate the real world IP core network. The emulated system fulfils its purpose for testing of the routing application of SGSN regarding different functionality and characteristics. This is done to ensure and verify that SGSN routing application meets its functional and technical requirements, and also helps to find undiscovered errors as well as helps to ensure that the individual components of routing application on SGSN are working correctly.</p>
43

Granskning och optimering av data- och IP-telefoninätverk

Eriksson, Jhonny, Karlsson, Joel January 2010 (has links)
The company Västra Mälardalens Kommunalförbund, VMKF, wishes to revise and optimize their present data and IP-telephony network as of today consists of the three municipalities Köping, Arboga and Kungsör. As a municipal corporation, they seek consultation regarding internal as well as external review and investigation of the main structure of the network, its functionality and safety. By today’s increasing demands of Internet accessibility, availability of services and security far more extends the requirement of a complete network design. The foundation of networking rests on the balance between each of these necessities. Therefore, it is of grave importance to optimize a network design, use of hardware and to minimize the administrative overhead. In particular, when the municipality is short of resources and time means money. By letting an impartial investigation of the network act as a starting point it was established that several improvement could be applied. Among these a reconstructed and improved network topology that includes subjects as routing, switching, safety and security, quality of service and technical administrative overhead and the implementation of a real time monitoring of network bandwidth consumption. / Företaget Västra Mälardalens Kommunalförbund, VMKF, har önskemål om att granska och optimera deras befintliga data- och IP-telefoninätverk som i dagsläget spänner över de tre kommunerna Köping, Arboga och Kungsör. Som ett kommunalägt företag önskar de konsultation rörande intern såväl som extern granskning och optimering av huvuddelen av nätverkets funktionalitet samt säkerhet. I och med dagens ökade Internetanvändning och funktionalitetsbehov ställs allt högre krav på tillgänglighet, säkerhet och användarvänlighet. Nätverksteknik bygger mycket på balansen mellan dessa tre punkter. Därför gäller det att optimera nätverkets design, hårdvaruanvändning och att minimera administrativa laster. Detta i synnerhet då kommunens resurser är knappa och då tid i dagens samhälle innebär pengar. Genom att låta en granskning över nätverket som det ser ut i dag ligga till grund konstaterades att flertalet förbättringsmöjligheter kunde genomföras. Bland dessa återfinns en omstrukturerad nätverksdesign som innefattar routing, switching, säkerhet, QoS och teknisk administration samt implementeringen av en realtidsövervakning av bandbreddsanvändning.
44

Integer programming approaches to networks with equal-split restrictions

Parmar, Amandeep 09 May 2007 (has links)
In this thesis we develop integer programming approaches for solving network flow problems with equal-split restrictions. Such problems arise in traffic engineering of internet protocol networks. Equal-split structure is used in protocols like OSPF and IS-IS that allow flow to be split among the multiple shortest paths. Equal-split assumptions also arise in peer-to-peer networks and road optimization problems. All the previous work on this problem has been focused on developing heuristic methods for the specific applications. We are the first ones to study the problem as a general network flow problem and provide a polyhedral study. First we consider a general multi-commodity network flow problem with equal split restrictions. This problem is NP-hard in general. We perform a polyhedral study on mixed integer linear programming formulation for this problem. Valid inequalities are obtained, and are incorporated within a branch-and-cut framework to solve the problem. We provide fast separation schemes for most of the families of valid inequalities. Computational results are presented to show the effectiveness of cutting plane families. Next, we consider the OSPF weight setting problem. We propose an integer programming formulation for this problem. A decomposition based approach to solve the problem is presented next. Valid inequalities, exploiting the structure, are obtained for this problem. We also propose heuristic methods to get good starting solutions for the problem. The proposed cutting planes and heuristic methods are integrated within a branch-and-cut framework to solve the problem. We present computational experiments that demonstrate the effectiveness of our approach to obtain solutions with tight optimality gaps as compared with default CPLEX. Finally, we consider an equal split flow problem on bipartite graphs. We present an integer programming formulation for this problem that models the equal-split in a different way than the multi-commodity network flow problem discussed before. Valid inequalities and heuristic methods for this problem are proposed, and are integrated within the branch-and-cut framework. We present computational experiments demonstrating the effectiveness of our solution strategy. We present an alternate formulation for the problem with some favorable polyhedral properties. Lastly, a computational comparison between the two formulations is presented.
45

Optimisation du Routage à État de Liens dans les Systèmes Autonomes Hybrides sur Internet

Cordero, Juan Antonio 15 September 2011 (has links) (PDF)
Ce manuscrit étudie la coexistence de réseaux fixes et de réseaux spontanés dans le coeur d'Internet. Plus particulièrement, on étudie le problème du routage dans un certain type de système autonome (AS) appelé AS hybrides, qui contiennent à la fois des réseaux ad hoc sans fil et des réseaux filaires. L'approche proposée dans ce manuscrit est d'adapter des protocoles actuellement utilisés dans les AS au coeur d'Internet, typiquement basés sur l'algorithme à état des liens, pour leur permettre d'opérer dans les réseaux ad hoc (MANETs) comme dans les réseaux filaires. Le manuscrit analyse donc l'utilisation du routage à état de liens dans les réseaux ad hoc. Différentes techniques sont ensuite proposées et évaluées théoriquement, dans le but d'optimiser la performance des protocoles à état de liens dans les AS hybrides. Le manuscrit étudie alors l'impact de ces techniques lorsqu'elles sont appliquées à OSPF, l'un des principaux protocoles actuellement utilisés dans les AS. Les performances d'OSPF dans les MANETs utilisant les différentes techniques étudiées sont ensuite analysées au moyen de simulations. Pour finir, le fonctionnement du protocole OSPF utilisant certaines des techniques étudiées est évalué au moyen d'expériences sur un réseau test réel.
46

Emulation of IP Core Network for Testing of the Serving GRPS Support Node (SGSN) Routing Application

Torkaman, Hossein January 2009 (has links)
This thesis aims to investigate a method and tool for emulation of the General Packet Radio Service (GPRS) core network needed as an environment to test the routing functionality. GPRS is the most widely adopted mobile packet data delivery technology in the world. It utilizes an Intranet Protocol (IP)-based core network and involves significant changes to the way the Global System for Mobile communications (GSM) air interface is structured. It also forms the basis of the future structure of mobile network transmission and switching. The Serving GPRS Support Node (SGSN) is the most fundamental node in GPRS. Ericsson produces and manages an increasing number of SGSN nodes in the world. One of main functionalities of SGSN node is to forward IP packets according to the destination address in the IP header on IP core network. In each new release of SGSN, or when implementation or upgrades have been done on routing application on SGSN, design and test engineers at Ericsson need to emulate the IP core network. This must be done with use of many routers to generate huge amounts of data that can simulate the real world IP core network. The major goal of this thesis was to analyze and verifying the use of a suitable and economical solution to emulating IP Core Network of the GPRS system for testing of different functionality of the routing application running in SGSN , instead of building up a physical Core Network with different infrastructure and many routers. The method chosen for emulating the IP core network with many routers, and investigated in the thesis, is based on a Cisco simulator called “Dynamips”, which runs many actual Cisco Internetwork Operating Systems (IOS) with many different models of Cisco products in a virtual environment on Windows or Linux platforms. With this simulator, engineers at Ericsson will be able to use this simulator to emulate IP core network easily and efficiently to accomplish system test cases. A conclusion of this work is that Dynamips could be used to emulate many complicated IP core network scenarios, with many routers to generate huge amounts of data to simulate the real world IP core network. The emulated system fulfils its purpose for testing of the routing application of SGSN regarding different functionality and characteristics. This is done to ensure and verify that SGSN routing application meets its functional and technical requirements, and also helps to find undiscovered errors as well as helps to ensure that the individual components of routing application on SGSN are working correctly.
47

Redundance v datových sítích / Redundancy in data networks

Šoun, Jan January 2010 (has links)
This thesis focuses on redundancy in data networks and on technologies which are used to achieve high availability in network infrastructure. This thesis is based on industry standards published by well-known standardization authorities. One proprietary technology which can effectively replace these standards and simplify the whole network is also presented in more detail. The theoretical part individually describes all such technologies and standards. The practical part deals with an appropriate combination of these technologies and their application in a specific product environment. This work is meant to describe the whole concept of high availability in network infrastructure and should be instrumental in understanding how these technologies are deployed in practice.
48

Arquitetura e implementação de um serviço de informações topologicas e de engenharia de trafego para sistemas RWA / Architecture and implementation of a topological information and traffic engineering service to RWA systems

Zuliani, Luiz Gustavo 12 April 2006 (has links)
Orientador: Mauricio Ferreira Magalhães / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-08T01:20:28Z (GMT). No. of bitstreams: 1 Zuliani_LuizGustavo_M.pdf: 512812 bytes, checksum: cab94937633f70467669b12635e8ccb1 (MD5) Previous issue date: 2006 / Resumo: Redes totalmente ópticas (fotônicas) controladas por GMPLS (Generalized MultiProtocol Label Switching) são a promessa para lidar com o crescente volume de tráfego IP. Os protocolos de sinalização e roteamento GMPLS, principalmente OSPF (Open Shortest Path First) e RSVP (Resource ReSerVation Protocol), trabalham de tal modo que o cálculo da rota para circuitos ópticos não considera a disponibilidade de comprimentos de onda (labels). Esta solução não é ótima em termos do uso de recursos de rede e da probabilidade de bloqueio de novos circuitos. Para aprimorar este quadro, algoritmos RWA (Routing and Wavelength Assignment) mais eficientes poderiam ser usados para calcular a rota e o comprimento de onda simultaneamente. Estes algoritmos RWA necessitam conhecer a topologia óptica de um modo ainda não descrito pelas atuais especificações do protocolo OSPF. Esta dissertação propõe extensões de Engenharia de Tráfego para o protocolo OSPF para permitir que o plano de controle GMPLS se beneficie do uso de algoritmos RWA mais eficientes. Um protótipo foi desenvolvido e instalado em uma rede óptica emulada para verificar a praticabilidade da solução proposta baseado na sobrecarga de tráfego gerado no plano de controle / Abstract: GMPLS-controlled all-optical networks are the promise to handle the increasing volume of IP traffic. The GMPLS routing and signaling protocols, mainly OSPF and RSVP, work in such a way that the route calculation for optical circuits does not take into account the wavelength (label) availability. This is not optimal in terms of network resources usage and blocking probability of new circuits. To deal with this scenario, more efficient RWA algorithms could be used to calculate the route and the wavelength assignment at one time. These RWA engines need to know the optical topology in a way that is not described by current OSPF standards. This dissertation proposes Traffic Engineering extensions to the OSPF protocol to enable the GMPLS control plane to take advantage of the most effective RWA classes. A prototype was developed and deployed in an optical-emulated copper-based network to verify its feasibility based on the bandwidth overhead generated in the control plane / Mestrado / Engenharia de Computação / Mestre em Engenharia Elétrica
49

Intelligent supervision of flexible optical networks / Supervision intelligente des réseaux optiques flexibles

Kanj, Matthieu 20 December 2016 (has links)
Les réseaux optiques dynamiques et flexibles font partie des scénarios d'évolution des réseaux de transport optique. Ceux-ci formeront la base de la nouvelle génération des réseaux optiques de demain et permettront le déploiement efficace des services tel que le Cloud Computing. Cette évolution est destinée à apporter flexibilité et automatisation à la couche optique, mais s'accompagne d'une complexité supplémentaire, notamment au niveau de la gestion et de la commande de cette toute nouvelle génération de réseau. Jusqu'à récemment, les protocoles de routage et de signalisation normalisés ont pris en compte plusieurs paramètres physiques tels que l'information spectrale de la bande passante, le format de modulation, et la régénération optique. Cependant, d'autres paramètres sont encore nécessaires (par exemple, les puissances optiques des liens, le gain des amplificateurs) afin de faire fonctionner efficacement de grands réseaux. Dans ce contexte, il y a un besoin d'étudier les réseaux optiques existants ainsi que les différentes méthodes de prise en compte de la couche photonique dans le plan de contrôle. Le but est d'avoir un réseau optique automatique, flexible et programmable, mais surtout efficace de point de vue économique et opérationnel. L'utilisation de la technologie à grille flexible a un impact sur les réseaux optiques existants, où presque tous les équipements devront être remplacés, ce qui entraînera un coût additionnel pour les opérateurs. Dans ce travail, nous étudions les réseaux optiques actuels et évaluons l'impact de la flexibilité sur les infrastructures existantes. Ensuite, nous identifions plusieurs paramètres optiques à contrôler et proposons des extensions protocolaires afin d'intégrer ces paramètres dans un plan de contrôle GMPLS. De plus, nous développons les algorithmes de routage et de signalisation qui permettent la mise en œuvre d'un plan de contrôle efficace qui répond au besoin de la flexibilité. Enfin, l'ensemble de nos propositions et de nos solutions sont évaluées sur plusieurs topologies réseaux avec des modèles de trafic différents dans le but de valider leur pertinence. / Dynamic and flexible optical networks are among the evolution scenarios of the optical transport networks. These form the basis of the new generation of optical networks of tomorrow and enable the effective deployment of services such as cloud computing. This evolution is intended to provide flexibility and automation to the optical layer. However, it results in additional complexity, particularly in terms of the management and control of this new network generation. Until recently, the standardized routing and signaling protocols have been taking into account several optical parameters like the spectral bandwidth information, modulation format, and optical regeneration. However, other parameters (e.g., link optical powers, gain of optical amplifiers) are still required in order to efficiently operate large optical networks. In this context, there is a need to study the existing optical networks and the different integration methods of the photonic layer in a control plane. The goal is to get an automatic optical network that is flexible, programmable, and at the same time efficient from an economical and operational perspective. The use of flexible grid technology has an impact on existing optical networks, where almost all the equipment must be replaced, resulting in an additional cost to network operators. In this work, we study the current optical networks and evaluate the impact of flexibility on the existing infrastructures. Then, we identify several physical parameters to be controlled and propose protocol extensions in order to integrate these parameters in the GMPLS control plane. In addition, we develop the routing and signaling algorithms that allow the implementation of an efficient control plane that addresses the need for flexibility. Finally, the set of our proposals and solutions are evaluated on multiple network topologies with different traffic patterns in order to validate their relevance.
50

Resource monitoring in a Network Embedded Cloud : An extension to OSPF-TE

Roozbeh, Amir January 2013 (has links)
The notions of "network embedded cloud", also known as a "network enabled cloud" or a "carrier cloud", is an emerging technology trend aiming to integrate network services while exploiting the on-demand nature of the cloud paradigm. A network embedded cloud is a distributed cloud environment where data centers are distributed at the edge of the operator's network. Distributing data centers or computing resources across the network introduces topological and geographical locality dependency. In the case of a network enabled cloud, in addition to the information regarding available processing, memory, and storage capacity, resource management requires information regarding the network's topology and available bandwidth on the links connecting the different nodes of the distributed cloud. This thesis project designed, implemented, and evaluated the use of open shortest path first with traffic engineering (OSPF-TE) for propagating the resource status in a network enabled cloud. The information carried over OSPF-TE are used for network-aware scheduling of virtual machines. In particular, OSPF-TE was extended to convey virtualization and processing related information to all the nodes in the network enabled cloud. Modeling, emulation, and analysis shows the proposed solution can provide the required data to a cloud management system by sending a data center's resources information in the form of new opaque link-state advertisement with a minimum interval of 5 seconds. In this case, each embedded data centers injects a maximum 38.4 bytes per second of additional traffic in to the network.&lt;p&gt; / Ett "network embedded cloud", även känt som ett "network enabled cloud" eller ett "carrier cloud", är en ny teknik trend som syftar till att tillhandahålla nätverkstjänster medan on-demand egenskapen av moln-paradigmet utnyttjas.  Traditionella telekommunikationsapplikationer bygger ofta på en distributed service model och kan använda ett "network enabled cloud" som dess exekverande plattform. Dock kommer sådana inbäddade servrar av naturliga skäl vara geografiskt utspridda, varför de är beroende av topologisk och geografisk lokalisering. Detta ändrar på resurshanteringsproblemet jämfört med resurshantering i datacentrum. I de fall med ett network enabled cloud, utöver informationen om tillgängliga CPU, RAM och lagring, behöver resursfördelningsfunktionen information om nätverkets topologi och tillgänglig bandbredd på länkarna som förbinder de olika noderna i det distribuerade molnet. Detta examensarbete har utformat, tillämpat och utvärderat ett experiment-orienterad undersökning av användningen av open shortest path first med traffich engineering (OSPF-TE) för resurshantering i det network enabled cloud. I synnerhet utvidgades OSPF-TE till att förmedla virtualisering och behandla relaterad information till alla noder i nätverket. Detta examensarbete utvärderar genomförbarheten och lämpligheten av denna metod, dess flexibilitet och prestanda. Analysen visade att den föreslagna lösningen kan förse nödvändiga uppgifter till cloud management system genom att skicka ett datacenters resursinformation i form av ny opaque LSA (kallat Cloud LSA) med ett minimumintervall av 5 sekunder och maximal nätverksbelastning av 38,4 byte per sekund per inbäddade data center.

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