Orientador: Edmundo Roberto Mauro Madeira / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-10T07:03:06Z (GMT). No. of bitstreams: 1 Paixao_ValeriaJottadosReis_M.pdf: 1508382 bytes, checksum: 5099f72d547bb027df24dd7692d43775 (MD5) Previous issue date: 2007 / Resumo: Um problema atual no mundo das ¿Redes de Computadores¿ é o fornecimento de QoS fim-a-fim na Internet a diferentes usuários, ou seja, a distintos tipos de serviços. Além disso, a demanda por este serviços'o vem aumentando uma vez que a Internet está sendo cada vez mais solicitada não somente para transferência de arquivos, web ou para tarefas relacionadas com o correio eletrônico, mas também para aplicações multimídia que solicitam meios de transporte mais precisos. A proposta desta dissertação é fornecer melhorias a uma plataforma MPLS-DiffServ, transformando a mesma em um sistema mais flexível e dinâmico no oferecimento de qualidade de serviço fim-a-fim. As novas características utilizam tipos de tráfegos amplamente encontrados na Internet, assim como dois parâmetros de monitoramento, a largura de banda do LSP e os níveis de descartes de pacotes. As inovações vêm no formato de novas políticas para o gerenciamento da rede em caso da ruptura dos acordos pré-estabelecidos com os clientes, além de uma nova estrutura introduzida no mecanismo de Engenharia de Tráfego que ajudará o sistema a fazer uma análise mais profunda do tráfego no LSP de modo que as decisões mais exatas e rápidas possam ser aplicadas a fim de recuperar circunstâncias ideais para atender às expectativas dos usuários finais. Na mesma plataforma foi feita a verificação das melhorias para as quais o sistema forneceu respostas bem sucedidas que estimulasse a ambição de fazer da plataforma uma opção de ferramenta para companhias que desejem simular novas políticas administrativas antes de executá-las em uma rede real que afetam usuários reais / Abstract: A current problem in the ¿Computer Network¿ world is to provide end-to-end QoS in the Internet to different users what means supply support to distinct types of services. Moreover, the demand for this support is increasing even more once the Internet is being handled not only for transferring files, accessing the web or for email tasks but also for multimedia applications, it means, services that require a more accurate transmission media. The proposal of this dissertation is to provide enhancements to an MPLS-DiffServ platform, making it up a more flexible and dynamic system to offer end-to-end QoS. The new features make use of types of traffic largely handled in the Internet as well as two monitor parameters, the LSP bandwidth and the levels of packet drop. The innovation comes in the format of new policies in order to manage the networks in case of break of agreements made with the clients, besides a new structure that was inserted in the ¿Traffic Engineering¿ mechanism that will help in a sense of deep analysis of the traffic in the LSP so that more accurate and fast decisions can be applied in order to recover ideal conditions to attend the expectations of the final users. On this framework the verification of the new improvements was done and, as a result, the system provided a successful response that copes with the ambition of making the platform an option tool for companies that wish to simulate new administrative policies just before to implement them in a real network that affects real users / Mestrado / Redes de Computadores / Mestre em Ciência da Computação

Orientador: Niederauer Mastelari / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-24T18:11:18Z (GMT). No. of bitstreams: 1 Cardoso_RaulMariano_M.pdf: 9927638 bytes, checksum: f9633c7839661e2f914d88b7d438913e (MD5) Previous issue date: 2014 / Resumo: Os computadores como conhecemos não são mais a maioria de dispositivos que se comunicam utilizando a Internet. Há alguns anos uma tendência pode ser observada neste sentido: "coisas" recebem pequenos computadores, e são representadas virtualmente, gerando informações de valor aos seus usuários. Esta nova fase de desenvolvimento da sociedade da informação é conhecida como "Internet das Coisas" e tem afetado tanto a relação das pessoas com a vida cotidiana, quanto os modelos de negócio correntes. Este trabalho mostra como esta tendência tecnológica, inserida no contexto dos Sistemas de Transportes, pode gerar aplicações de grande relevância. Com este objetivo, metodologias que pudessem embasar o projeto foram buscadas. Um modelo arquitetural de referência foi utilizado para embasar o projeto e design de um sistema distribuído focado em aplicações específicas. A tecnologia RFID foi utilizada, com leitores e etiquetas eletrônicas, para projetar um arranjo de dispositivos que identifique os veículos e detecte sua presença nas entradas e saídas de um local restrito de interesse. Microcontroladores de baixo custo, de código aberto, tanto em hardware quanto em software, e com capacidade de se comunicar através da Internet também foram definidos por este projeto. Localmente, estes dispositivos filtram informações, mantêm bases de dados reduzidas, monitoram sensores e controlam atuadores. Para gerenciar os dispositivos desta rede, é proposta a utilização de serviços na rede, estabelecendo assim a possibilidade de uma arquitetura em nuvem. Este servidor, por sua vez, deve coordenar os dispositivos distribuídos, obtendo informações da rede que devem sincronizar os bancos de dados e também prover informações de estado dos controladores. O foco principal é o estabelecimento de uma arquitetura e infraestrutura que possam suportar as aplicações propostas. Um estudo de caso foi realizado considerando o campus da Universidade Estadual de Campinas. A primeira aplicação viável de um projeto como este é o controle de acesso veicular ao campus universitário, através da implantação de leitores RFID nas portarias, em conjunto com controladores, cancelas automáticas e sensores de presença. Isso motivou o desenvolvimento de uma prova de conceito. A instrumentação das portarias permite que os veículos sejam automaticamente identificados quando adentram o espaço restrito do campus, gerando informações de valor para outras aplicações possíveis. Dentre as aplicações previstas estão: controle de estacionamento privativo automático, sinalização interativa através de placas eletrônicas, informação de horários de transporte coletivo e elaboração de relatórios periódicos sobre o trânsito. Para que todas estas aplicações sejam disponibilizadas a comunidade, serão necessários trabalhos futuros de pesquisa e desenvolvimento / Abstract: Computers as we know are no longer the majority of devices that communicate using the Internet. A few ago years a trend can be observed in this direction: "things" get small computers, and are represented virtually generating information of value to its users. This new phase of development of the information society is known as the "Internet of Things" and has affected both people's relationship with everyday life, as the current business models. This work shows how this technological trend, inside the context of Transportation Systems, can generate highly relevant applications. With this objective, methodologies that could base the project were sought. An architectural reference model was used to support the project and design of a distributed system focused on specific applications. RFID technology was used with electronic tags and readers, to develop a devices arrangement that identifies vehicles and detect their presence in the inputs and outputs of a restricted location of interest. Low cost, open source and Internet ready devices were also described for work¿s interest. Locally, these devices filter information, maintain reduced data bases, monitor sensors and control actuators. To manage the devices was proposed the use of network services, establishing the possibility of cloud architecture. The server must coordinate the distributed devices, getting information from the network that must synchronize the databases and also provide status information of the controllers. The main focus is to establish an architecture and infrastructure that can support the proposed applications. A case study was designed aiming the campus of the State University of Campinas. The first viable implementation of such a project is the control of vehicular access to the campus, through the installation of RFID readers, controllers, automatic barriers and presence sensors. That result in a deployed proof of concept. The instrumentation of the campus access allows vehicles to be automatically identified when they enter the restricted space of the campus, generating valuable information for other possible applications. Among the intended applications include: automatic control of private parking, signaling through interactive electronic boards, information on public transportation schedules and reporting generation about transit. In order to all these applications are available for the community, needed further in research and development / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica

Traffic Engineering (TE) uses methods and models from a variety of mathematical fields, such as statistics and optimization, to improve the performance of telecommunication networks. In this thesis, we study TE problems dealing with networks that impose single-path routing. As the name infers, in this type of routing, the traffic flow of each "commodity" cannot be split in its path between its origin and destination. Given its cheap cost, single-path routing is widely used in today's data centers, where thousands of stored servers perform computations or host Internet services. One common case of single-path routing is the one enforced by the Spanning Tree Protocol (STP) in switched Ethernet networks. The STP requires the network to keep its activated links loop-free, while maintaining the other redundant links ready for back-up, in case of link failure. The Multiple Spanning Tree Protocol (MSTP) extends the STP by installing multiple virtual networks compliant with the STP, over a single physical topology. Therefore, the MSTP is greatly beneficial for network service providers, as it allows for a more efficient use of the existing resources.Network design problems dealing with the MSTP are generally highly combinatorial and very hard to solve. As such, TE literature mainly suggests heuristic methods, which can quickly produce reasonable designs. Notwithstanding, due to a scarce existence of lower bounds to the optimum values of such problems, there is little knowledge about the quality of the solutions provided by these heuristics.In this sense, we propose mathematical programming models and methods that can provide optimal designs for these networks, or at the very least, obtain valid lower bounds. Taking into mind the goal of avoiding congestion in the network, we focus on two problems that deal with the following load-balancing objectives: the minimization of the worst-case link utilization, and the minimization of flow costs given by piecewise linear functions that penalize heavily-loaded links. The study of both these problems yielded relevant by-products: the first is the study of a MSTP network design problem, where we minimize the total load, and the second is the study of a fundamental unsplittable multicommodity flow problem with piecewise linear costs.For all the considered problems, we provide studies of complexity, extensive polyhedral studies to compare the proposed formulations, and a wide array of computational experiments to evaluate the performance of the proposed models and methods. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

M.Phil. (Civil Engineering) / The SIDRA (Signalised Intersection Design and Research Aid) is calibrated for South African traffic conditions. Traditionally, South African traffic engineers made use of American or Australian based information to analyze traffic operations at signalised intersections. Two major models used in South Africa are HCM (Highway Capacity Manual) by the Transportation Research Board in the USA and SIDRA by the Australian Road Research Board. SIDRA is gaining popularity in South Africa because of the practical problems of the mirror image, which has to be maintained in using the HCM method due to the right side driving in the USA and other possible differences on driver behavior, vehicle attributes, geometric design and traffic control. SIDRA seems to be more suitable for South African conditions. Recently the use of SIDRA in this country has been increased to 44 organizations. This study aims to prepare a unified default file for South African users. Due to the large number of model parameters in SIDRA, priority is given to important ones for which information is readily available. And this study is confined to signalised intersections rather than all intersection types.

In today’s scenario, energy efficiency has become one of the most crucial issues for Data Center Networks (DCN). This paper analyses the energy saving capability of a Data center network using Segment Routing (SR) based model within a Software Defined Network (SDN) architecture. Energy efficiency is measured in terms of number of links turned off and for how long the links remain in sleep mode. Apart from saving the energy by turning off links, our work further efficiently manages the traffic within the available links by using Per-packet based load balancing approach. Aiming to avoid congestion within DCN’s and increase the sleeping time of inactive links. An algorithm for deciding the particular set of links to be turned off within a network is presented. With the introduction of per-packet approach within SR/SDN model, we have successfully saved 21 % of energy within DCN topology. Results show that the proposed Per-packet SR model using Random Packet Spraying (RPS) saves more energy and provides better performance as compared to Per-flow based SR model, which uses Equal Cost Multiple Path (ECMP) for load balancing. But, certain problems also come into picture using per-packet approach, like out of order packets and longer end to end delay. To further solidify the effect of SR in saving energy within DCN and avoid previously introduced problems, we have used per-flow based Flow Reservation approach along with a proposed Flow Scheduling Algorithm. Flow rate of all incoming flows can be deduced using Flow reservation approach, which is further used by Flow Scheduling Algorithm to increase Bandwidth utilization Ratio of links. Ultimately, managing the traffic more efficiently and increasing the sleeping time of links, leading to more energy savings. Results show that, the energy savings are almost similar in per-packet based approach and per-flow based approach with bandwidth reservation. Except, the average sleeping time of links in per-flow based approach with bandwidth reservation decreases less severely as compared to per-packet based approach, as overall traffic load increases.

The master’s thesis deals with a solution of a complicated traffic situation on the Přímá – Nábřeží intersection in Zlin. The first part of the thesis focuses on the diagnostic of the current state of the junction. In the second part, the author compares possible solutions, traffic light control is chosen as the best. Traffic light plans are designed and coordinated with a nearby traffic light controlled intersection Tomáše Bati – Přímá. It the last part, the solution is verified and represented by a microsimulation.

In der heutigen, digitalisierten Gesellschaft ist es für Internet Service Provider (ISP) zunehmend wichtig, den ansteigenden Anforderungen ihrer Endnutzer gerecht zu werden. Eine Möglichkeit diese Herausforderung zu adressieren ist es, die vorhandene Netzwerkinfrastruktur durch den Einsatz von Traffic Engineering Technologien möglichst effizient zu betreiben. Segment Routing (SR) bietet eine elegante Möglichkeit Traffic Engineering einzusetzen ohne viel Overhead zu erzeugen. Obwohl es bereits verschiedene Ansätze zum SR Traffic Engineering gibt, verbleiben die meisten dieser Arbeiten auf einer sehr theoretischen Ebene und versäumen es, praktische Anforderungen und Nebenbedingungen zu erkennen und miteinzubeziehen. Diese Dissertation schließt die Lücke zwischen Theorie und Praxis, indem die spezifischen Anforderungen eines Tier 1 ISPs identifiziert werden, neue Optimierungsmodelle kreiert werden, welche ebendiese Nebenbedingungen erfüllen, und, schlussendlich, eine detaillierte Evaluation mittels realer Messdaten von selbigem ISP durchgeführt wird. Die Optimierungsmodelle berücksichtigen praktisch relevante Anforderungen wie die Minimierung der Anzahl der verwendeten SR Tunnel und SR Label, die proaktive Minimierung von Überlast in einer Vielzahl verschiedener Fehlerszenarien und weitere. Es wird darüber hinaus gezeigt, dass SR Optimierungen größtenteils unabhängig von der zugrundeliegenden Linkmetrikkonfiguration funktioniert und dass SR das Potential aufweist, Routingkonfigurationen zu erzeugen, die für längere Zeitabschnitte stabil bleiben.

No description available.

GMPLS is a still developing protocol family which is indented to assume the role of a control plane in transport networks. GMPLS is designed to provide traffic engineering in transport networks composed of different network technologies such as wavelength switched optical networks, Ethernet networks, point-to-point microwave links, etc. Integrating the different network technologies while using label switched paths to provide traffic engineering poses a challenge. The purpose of integrating multiple technologies under a single GMPLS control plane is to enable rapid service provisioning and efficient traffic engineering. Traffic engineering in networks provides two primary advantages, network resource utilization optimization and the ability to provide Quality of Service. Utilizing network resources more efficiently translates to lower expenditures for the network provider. Quality of Service can be used to provide the customer with for example guaranteed minimum bandwidth packet services. Specifically this thesis focused on the problems of signaling and establishing Forward Adjacency Label Switched Paths (FA-LSPs), and on a experimental method of connecting different network technologies. A testbed integrating an Ethernet network and a wave length division multiplexing network was used to show that the proposed solutions can work in practice. / GMPLS består av en samling protokoll under utveckling, de är tänkta att anta rollen som kontrollplan i transportnätverk. GMPLS är designat för att tillhandahålla trafikplanering i transportnätverk bestående av flera olika nätverksteknologier såsom Ethernet, våglängds switchande nätverk m.fl. Integration av dessa olika nätverksteknologier under ett gemensamt kontrollplan och uppsättning av ”label switched paths” i dataplanet är en utmaning. Syftet med att integrera multipla teknologier under ett ensamt GMPLS kontroll plan är att snabbt kunna tillhandahålla tjänster över nätverket samt möjliggöra advancerad trafikplanering. Trafikplanering i nätverk ger två stora fördelar, optimering av utnyttjandet av nätverksresurser samt ökade möjligheter att erbjuda ”Quality of Service” till kunder. Bättre utnyttjande av nätverksresurser innebär lägre kostnader för nätverksleverantören medans ”Quality of Service” kan ge kunden t.ex. en garanterad bandbredd. Specifikt fokuserar denna avhandling på problemen med att signalera och etablera ”Forwarding Adjaceny Label Switched Paths” samt en experimentell metod som båda sammankopplar olika typer av nätverk. En testbed bestående av ett Ethernet nätverk samt ett optiskt våglängdsswitchande nätverk användes för att visa att lösningarna kan fungera i praktiken.

Thesis: M.S., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 1979 / Includes bibliographical references. / by Han-Ngee Tan. / M.S. / M.S. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science