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Se plantea un problema de cambio de infraestructura y rediseño de red de comunicaciones en una empresa dedicada al servicio de transferencia electrónica de fondos interbancarios a través de una red de cajeros automáticos y al procesamiento y administración de tarjetas de débito y crédito. Tanto en el frente de los cajeros automáticos o terminales transaccionales, como en el frente de los computadores que autorizan las transacciones, se han ido experimentando y exigiendo cambios, los cuales no solo han involucrado nuevas tecnologías y aplicaciones, sino también la apertura a protocolos de comunicación como el TCP/IP con nuevos servicios y posibilidades, en un servicio financiero, que por mantener altos niveles de seguridad, mantenía protocolos de comunicación “heredados” como el X.25 y el SNA. En el presente documento se revisa la situación inicial de la red, los servicios y las necesidades del negocio, y la evolución de las redes de cajeros. Con el fin de conseguir los objetivos, se plantean propuestas de solución para dar soporte a las aplicaciones con protocolos “heredados” en una red IP, se revisan las alternativas técnico-económicas de enlaces de comunicación, las propuestas para la renovación de la infraestructura de comunicaciones y seguridad, y finalmente una serie de recomendaciones para la implantación y la migración a la red IP. Con un adecuado planeamiento e implantación de políticas de seguridad adecuadas, en una red privada, publica o compartida con otra institución, es posible conseguir una red de cajeros automáticos TCP/IP eficiente, segura, con alta disponibilidad, y capaz de brindar mayores servicios.

Virginia Tech researchers have developed a broadband channel sounder that can measure channel quality while a wireless network is in operation. Channel measurements from the broadband sounder hold the promise of improving TCP/IP performance by trigging configuration changes in an adaptive data link layer protocol. We present an adaptive data link layer protocol that can use different levels of forward error correction (FEC) codes and link layer automatic retransmission request (ARQ) to improve network and transport layer performance. Using a simulation model developed in OPNET, we determine the effects of different data link layer protocol configurations on TCP/IP throughput and end-to-end delay using a Rayleigh fading channel model. Switching to higher levels of FEC encoding improves TCP/IP throughput for high bit error rates, but increases end-to-end delay of TCP/IP segments. Overall TCP/IP connections with link layer ARQ showed approximately 150 Kbps greater throughput than without ARQ, but lead to the highest end-to-end delay for high bit error rate channels. Based on the simulation results, we propose algorithms to maximize TCP/IP throughput and minimize end-to-end delay using the current bit error rate of the channel. We propose a metric, carrier-to-interference ratio (CIR) that is calculated from data retrieved from the broadband channel sounder. We propose algorithms using the carrier-to-interference ratio to control TCP/IP throughput and end-to-end delay. The thesis also describes a monitor program to use in the broadband wireless system. The monitor program displays data collected from the broadband sounder and controls the settings for the data link layer protocol and broadband sounder while the network is in operation. / Master of Science

Complexe : tel est l’adjectif qui, sans aucun doute, résume le mieux la question de l’architecture normative du réseau internet. Complexe, cette question l’est pour deux raisons. La première tient à l’identification des normes qui constituent cette architecture ; la seconde tient à leur objet. Tout d’abord, s’agissant de l’identification de normes, cette entreprise s’avère éminemment complexe dans la mesure où voilà un concept, la norme, qui renvoie à des réalités si différentes, qu’il est peu aisé de le définir. Après avoir établi l’existence de normes qui règlent la conduite des bâtisseurs du réseau, il faudra, en outre, s’interroger sur la nature de ces normes. Là encore, cette problématique n’est pas aussi facile à résoudre qu’il y paraît. Il n’existe, en effet, aucun critère de distinction entre les différentes espèces de normes qui fasse l’unanimité chez les auteurs. Concernant, ensuite, la seconde raison pour laquelle la question de l’architecture normative de l’internet est placée sous le signe de la complexité, c’est vers l’objet des normes qui la composent qu’il conviendra de se tourner : l’organisation de la société numérique. Il s’agit là, d’un système complexe. Si l’on adhère à cette idée, il doit corrélativement être admis que le schéma auquel répondent les normes par l’entremise desquelles le contrôle de pareil système est effectué, est très différent de celui dans lequel s’inscrivent les normes qui nous sont les plus familières : les règles juridiques. Alors que la genèse des premières est sous-tendue par un mécanisme d’auto-organisation, la création des secondes procède d’un acte de volonté. La différence entre les deux schémas est de taille : dans un cas, c’est la spontanéité qui commande la production des règles de conduite, dans l’autre c’est la raison. Dans l’univers numérique, l’opposition entre ces deux schémas normatifs se retrouve : elle se traduit par la concurrence qui existe entre les ordres numériques et juridiques. Aussi, est-ce à travers cette concurrence à laquelle se livrent ces deux systèmes normatifs que sera décrite l’architecture normative du réseau internet. / Complex is undoubtedly the adjective that best summarises the issue of the normative architecture of the Internet network. This issue is complex for two reasons. The first one results from the identification of the rules that make up this architecture and the second one from their purpose. First of all, the identification of the rules proves to be an extremely complex matter, since this concept of the rule is not so easy to define, as it refers to such a wide range of realities. After establishing the existence of the rules which set the behaviour of network builders, it is necessary to raise the question of the the nature of the rules. Here again, solving this issue is not as easy as it seems. In fact, in literature there is no universal way to distinguish the various types of rules. Secondly, the rules that compose the normative architecture of the internet aim at organising the digital society. Yet, this is a complex system. If one accepts the idea, one has to correlatively claim that the rule-complying scheme that enables such a system to be controlled is very different from that which rules more common rules for us, such as the rules of law. While the former is underpinned by a self organising mechanism, the creation of the latter stems from an act of willing. The difference between both schemes is significant: in the first case spontaneity controls the setting up of rules of conduct, while in the second case reason does. The opposition between these two normative schemes can be found in the digital universe too. It is conveyed by the existing competition between the digital and the legal orders. That is why the normative architecture of the Internet network will be described through the competition between these two normative systems.

Made available in DSpace on 2016-04-04T18:31:42Z (GMT). No. of bitstreams: 1 DANIEL ADORNO GOMES-2.pdf: 6264883 bytes, checksum: cca792dc8793e5981e4202615260916c (MD5) Previous issue date: 2015-06-26 / This paper presents a proposal for architecture for interconnection of wireless sensor networks and the Internet using only the application layer, without the need to change the protocol stack of both networks. The architecture is based on the HTTP protocol, proposing the use of web services technology to interconnect the two network standards. From the installation of a wireless sensor network in a closed environment, its interconnection was performed with the Internet based on the proposed architecture using open standard technologies, the protocol for REST web services and cloud computing structure of the company Amazon Web Services. Information was collected to evaluate the functionality, reliability and system efficiency, accordingly to the ABNT standard, ISO / IEC 9126. The results showed the feasibility of implementing this proposal because it was shown that the interconnection is possible between these network standards using the application layer, reliably, efficiently and with the use of low cost resources. This study might encourage proposals to extend the accessibility of sensor networks to mobile devices. / Este trabalho apresenta uma proposta de arquitetura para interconex?o de redes de sensores sem fio e a Internet utilizando somente a camada de aplica??o, sem que haja a necessidade de altera??o da pilha de protocolos de ambas as redes. A arquitetura baseia-se no protocolo HTTP, propondo a utiliza??o da tecnologia de web services para interconectar os dois padr?es de rede. A partir da instala??o de uma rede de sensores sem fio num ambiente fechado, foi realizada a sua interconex?o com a Internet com base na arquitetura proposta, utilizando tecnologias de padr?o aberto, o protocolo para web services REST e uma estrutura de computa??o em nuvem da empresa Amazon Web Services. Foram coletadas informa??es para que se pudesse avaliar a funcionalidade, a confiabilidade e a efici?ncia do sistema, de acordo com a norma da ABNT, NBR ISO/IEC 9126. Os resultados apontaram para a viabilidade de implementa??o dessa proposta, pois, demonstrou-se que ? poss?vel a interconex?o entre esses padr?es de rede utilizando a camada de aplica??o, de forma confi?vel, eficiente e com a utiliza??o de recursos de baixo custo. Este estudo pode embasar propostas para estender a acessibilidade das redes de sensores aos dispositivos m?veis.

<p>Ova doktorska disertacija predstavlja istraživački rad sproveden sa ciljem da re&scaron;i problem koji se odnosi na realizaciju povezivanja laboratorijskog, medicinskog mernog uređaja sa personalnim računarom. Rezultat istraživačkog rada je op&scaron;ta metoda koja obezbeđuje efikasnu konverziju podataka I2S protokola u TCP/IP protokol.</p> / <p>This doctoral thesis presents the research work carried out in order to solve a practical problem, the realization of a connection between a medical measuring device and a personal computer. The result of the research is a general method that provides efficient data conversion from the I2S protocol to the TCP/IP protocol.</p>

Detta arbete var beställt av Sjöfartshögskolan i Kalmar. Skolan ville ha en enhet som kunde mäta aktiv-, reaktiv- och skenbar effekt, ström, spänning, frekvens och cosϕ på en generator och som kommunicerade vidare dessa värden till en PLC. Detta för att kunna lastfördela lasten mellan ett antal generatorer i kursen Tillämpad elteknik 15 hp där studenterna bygger en generatorinstallation med tre generatorer. Ett funktionsblock för lastfördelning skulle också programmeras. Prototypen som konstruerades baserades på en Arduino Ethernet och kommunikationen löstes med Modbus TCP/IP över Ethernet. Ett lastfördelningsprogram programmerades i form av ett funktionsblock som studenterna kunde importera till CoDeSys v2.3 och använda i sina installationer. Prototypen kunde läsa av värdena med ungefär samma noggrannhet som ett kommersiellt instrument som använder sig av samma mätteknik som prototypen. Uppdateringsfrekvensen var dock lägre än hos ett kommersiellt instrument. Kommunikationen med PLC:n fungerade utan problem. Då ingen undervisning hölls i arbetets slutskede kunde inte lastfördelningen testas på en fullskalig anläggning. Lastfördelningsprogrammet klarade dock av att hålla rätt frekvens på en ensam generator och fungerade som tänkt när programmet testades i en simulator. Prototypen gav fel mätvärden vid kapacitiv last. Vid jämförelse med en kommersiell tångamperemeter visade sig mätfelet bero på mätmetoden då båda gav liknande resultat. Som referens användes en professionell elkvalitetsanalysator. Alla uppdragsgivarens krav blev uppfyllda och arbetet kommer att kunna användas i undervisningen. / This thesis was ordered by Kalmar Maritime Academy. The request was for a device that could measure active, reactive and apparent power, as well as frequency, voltage, current and cosϕ on a generator. The measured values would be communicated to a PLC for use in a load sharing program between a number of generators in the course Tillämpad elteknik, 15 ECTS. In that course the students constructs a three-generator electric power grid. Included in the request was also to program a load sharing program. The prototype being constructed was based on the Arduino Ethernet, and the communication was enabled by means of the Modbus TCP/IP protocol over Ethernet. A load sharing program was created in the form of a function block which the student could import into the CoDeSys for use in the generator systems. The prototype could measure values with close to the same accuracy as a commercial available instrument that were using the same technique for measuring. The refresh rate was however lower than the commercial available instrument. Communication with the PLC worked without any issues. No full-scale testing could be done since no course was held during the final stages of the thesis, however the load sharing program could keep frequency on a single generator alone and worked in a simulated soft environment. Measuring errors occurred when measuring a capacitive load. When comparing to a commercial available clamp meter, the same errors occurred. As a reference a professional power and energy quality analyser was used. All the requests were fulfilled and the result of this thesis will be used in the educational programme at the Academy.

Includes index.

Submitted by Milena Rubi (milenarubi@ufscar.br) on 2017-10-09T14:35:22Z No. of bitstreams: 1 FRATE_Marcelo-2017.pdf: 8466810 bytes, checksum: 9438c26c84ebe90cd741672c8c04d726 (MD5) / Approved for entry into archive by Milena Rubi (milenarubi@ufscar.br) on 2017-10-09T14:35:33Z (GMT) No. of bitstreams: 1 FRATE_Marcelo-2017.pdf: 8466810 bytes, checksum: 9438c26c84ebe90cd741672c8c04d726 (MD5) / Approved for entry into archive by Milena Rubi (milenarubi@ufscar.br) on 2017-10-09T14:35:45Z (GMT) No. of bitstreams: 1 FRATE_Marcelo-2017.pdf: 8466810 bytes, checksum: 9438c26c84ebe90cd741672c8c04d726 (MD5) / Made available in DSpace on 2017-10-09T14:35:53Z (GMT). No. of bitstreams: 1 FRATE_Marcelo-2017.pdf: 8466810 bytes, checksum: 9438c26c84ebe90cd741672c8c04d726 (MD5) Previous issue date: 2017-02-23 / Não recebi financiamento / Since the emergence of the Software-Defined Networking (SDN), and, more precisely, since the development of an open interface in 2008 called OpenFlow protocol, it is being observed that this new networking paradigm is deeply remodeling the IP-protocol- based networks. It means that new mechanisms of provision services are being possible, which ensures scalability and reduces costs. Although this new paradigm has been created to centralize the control logic, there is the possibility of decentralizing it through the parceling of control tasks between two or more controllers. In this scenario, the subdivision of administrative domain in smaller subdomains in order to have each of them being controlled by one single controller has been an alternative to ensure scalability in SDN. The OpenFlow protocol allows communication among switches and controllers to another controller. However, the protocol does not define how this communication between one controller to other should be done. It is mandatory, therefore, the development of protocol independent solutions able to distribute this logic inside the same administrative domain. New proposals have been arisen, but their applications either use equal controllers or demand the development of new controllers specifically designed. This master’s research aims to offer the fundamentals to the development of an architecture here so called Orch Flow, able to receive application demands and organize them in a way it provides requested services through an OpenFlow network designed with two or more different implementation controllers. The OrchFlow architecture that is being proposed accomplishes its task through handling multiple OpenFlow controllers hierarchically and providing network access through three distinct modes: Proactive, Reactive and Hybrid. / Desde o surgimento das Redes Definidas por Software e mais especificamente à partir de 2008 com o desenvolvimento de uma interface aberta, o protocolo OpenFlow, é possível observar que este novo paradigma de redes está revolucionando as redes baseadas no protocolo IP, possibilitando a criação de novos mecanismos de aprovisionamento de serviços, garantindo a escalabilidade e reduzindo custos. Embora este novo paradigma tenha sido criado para a centralização da lógica de controle, existe a possibilidade de descentralizá-la através da divisão das tarefas de controle entre dois ou mais controladores. Neste cenário, subdividir o domínio administrativo em subdomínios menores e fazer com que cada subdomínio seja controlado por um controlador tem sido uma alternativa para garantir escalabilidade em Software-Defined Networking (SDN). O protocolo OpenFlow permite a comunicação entre switches e controladores, entretanto ele não define como deve ser feita a comunicação de um controlador para outro controlador. Faz-se necessário, portanto, o desenvolvimento de soluções independentes do protocolo, capazes de distribuir essa lógica dentro de um mesmo domínio administrativo. Neste cenário, novas propostas vão surgindo, porém as aplicações desenvolvidas ou fazem uso de controladores iguais ou são criados novos controladores especificamente para essa finalidade. Esta pesquisa de mestrado tem como objetivo o desenvolvimento de uma arquitetura, aqui denominada de OrchFlow, capaz de receber solicitações de aplicações, orquestrando as requisições a fim de prover os serviços solicitados numa rede OpenFlow com dois ou mais controladores de implementações diferentes. A arquitetura OrchFlow, desenvolvida para esta pesquisa de mestrado, realiza essa tarefa através da orquestração de múltiplos controladores OpenFlow atuando de forma hierárquica, provendo o acesso à infraestrutura da rede através de três modos distintos: o Proativo, o Reativo e o Híbrido.

Made available in DSpace on 2016-06-02T19:05:31Z (GMT). No. of bitstreams: 1 2017.pdf: 2776743 bytes, checksum: cc39daf3470ef4356480296d650d108c (MD5) Previous issue date: 2007-11-26 / Regarding new computational and networking requisites such as wireless networks, mutihoming interfaces, load-balancing mechanisms and several other middleboxes [1] present today, these facts, allied to the static and conservative nature of the Internet and its sheer size turn the capability to correct these problems an almost impossible attempt, as it demands structural changes. In the Internet inception, in the late 70th, neither mobility nor multihoming where foreseen in its original intents. In this sense, the proposition of a novel naming architecture for the Internet to identify univocally services and data, irrespective to its node characteristics, would have an acute changing effect and will allow its elements to be precisely represented and authenticated. In order to achieve these purposes, the use of Virtual Networks was considered as it allows the incremental introduction of new technologies, protocols and applications being itself a more viable alternative when compared to several failed attempts to introduce new structural changes to the Internet [2; 3]. A proposal for a taxonomy for Virtual Networks was described here as a result of a site survey that was conducted to function as subject to this architecture proposition. Besides, a literature investigation of related projects followed by a network testbed of several protocols originated the proposition of a Layered Naming Architecture for the Internet using Virtual Networks. / Face a vários novos requisitos de comunicação demandados por equipamentos em desenvolvimento constante, tais como computadores móveis portadores de múltiplas interfaces comunicantes, devido à inserção de diversos middleboxes [1], o modelo arquitetural TCP/IP necessita ser aprimorado para suportar novas tecnologias e protocolos. Originalmente, quando a Internet foi projetada, no final dos anos 70 nem mobilidade nem multihoming (i.e. equipamento com diversas conectividades físicas simultâneas) foram considerados. Pela proposição de uma nova arquitetura de nomeação para a Internet, que seja capaz de identificar univocamente qualquer entidade comunicante, bem como proporcionar suporte às tecnologias já extensamente utilizadas, este trabalho objetivou promover a mobilidade e o suporte a diversos middleboxes para a Internet, principalmente no que diz respeito à identificação e à autenticação de nós e objetos (i.e. serviços, dados e usuários). Almejando atingir tal objetivo utilizou-se a tecnologia de Redes Virtuais, que permite uma adesão incremental de suas funcionalidades, protocolos e aplicações. Esta abordagem não representa, portanto, um modelo cujas mudanças à arquitetura da Internet causam-lhe transformações estruturais, diferentemente de outras propostas que abordaram este problema desta forma sem sucesso [2; 3]. Para tanto, uma taxonomia de Redes Virtuais foi proposta e avaliada por um estudo de caso que compreendeu a sua aplicação prática. Além disso, realizou-se uma análise de bancada de redes de diversos protocolos e o estudo das propostas da literatura associada. Tais realizações culminaram na proposta de uma Arquitetura de Nomeação para a Internet utilizando Redes Virtuais Overlay.