Esta dissertação descreve os métodos, medidas e análises feitas para otimizar a rede de comunicação de dados do Instituto de Física de São Carlos. As tecnologias e protocolos utilizados na rede são apresentados. Especial atenção é dada a análise do desempenho de VLANs utilizando inicialmente o protocolo LANE no núcleo ATM da rede. Neste caso a rede é composta de switches ATM e ATM-Ethernet. Medidas comparativas foram realizadas com a utilização da tecnologia Fast Ethernet no backbone, que possui uma capacidade de transmissão relativamente próxima da ATM de 155Mbps. Melhores resultados obtidos com a implementação de sub-redes maiores, reduzindo em um numero menor de sub-redes, são discutidos e apresentados. Análises estatísticas baseadas apenas no tempo de resposta da rede são apresentados para avaliar o desempenho das alterações efetuadas nas configurações da rede. Mesmo que o tráfego tenha aumentado muito durante esses anos e que vários serviços tenha sido agregados a esta rede, foi possível adequar o desempenho as novas necessidades beneficiando-se da evolução tecnológica que os equipamentos de rede de dados trouxeram ao IFSC. / This work describes the methods, measures and analyses performed aiming to optimize the data communication network from the Physics Institute of Sao Carlos as well as the technologies and protocols used in the network recently. Special care is given to the analysis of the VLANs performance using, initially, the LANE protocol over ATM which has its core based on pure ATM and ATM-Ethernet switches. Comparative measures had been carried out using a backbone working on a Fast Ethernet technology, which seems to have a very close transmission rate from the ATM 155Mbps. This work also discusses best results acquired with the implementation of larger networks reducing the number of subnetworks, statistical analyses based on time delay of the network in order to evaluate the performance of the changes made on its configuration. Even though the traffic from the Institute has been increased over these years and several services have been added to the network, it was completely possible to adapt the performance to the needs, using the benefits of the technological evolution which the network equipments had brought to the Institute.

Orientador: Nobuo Oki / Banca: Artur Pantoja Marques / Banca: Dilvan de Abreu Moreira / Resumo: Com a globalização e a evolução tecnológica, a capilaridade das instituições, sejam elas públicas ou privadas, é realidade irreversível. O uso de computadores cada vez mais velozes e com elevada capacidade de armazenamento possibilitou a centralização das informações. Nesse contexto, surge a necessidade de interligar os sistemas computacionais com o objetivo de trocar informações, independentemente da região geográfica. A Internet, utilizando tecnologias de redes de dados, com arquitetura projetada para suportar em nível mundial a comunicação entre computadores, passa a ser a principal ferramenta utilizada na interligação de locais geograficamente distribuídos. Com a tecnologia e infraestrutura disponível para efetivar a comunicação, surge também a necessidade de garantir que os sistemas estejam ativos o maior tempo possível, atendendo a desempenho compatível às atividades desenvolvidas, pois as instituições passam a depender da interação entre os sistemas computacionais, independente do ponto do planeta em que estejam. Este trabalho propõe modelar, desenvolver e realizar ensaios de uma ferramenta que auxilie no monitoramento de pontos interligados por redes de comunicação dados sobre protocolo TCP/IP distribuídos geograficamente. O modelo consiste em monitorar um ou mais pontos, visualizados sobre um mapa com o traçado do perímetro político geográfico da área atendida. Em suma, propõe-se utilizar as ferramentas básicas de teste de conectividade nas redes de comunicação de dados, associadas aos conceitos de georreferenciamento e geoprocessamento / Abstract: The globalization and technological evolution, allowed the grow of institutions public or private over the entire world with highest capillarity. The development of computers becoming faster and with large storage capacity allowed the centralization of information. In this context the necessity of linking computer systems with the aim to exchange information regardless of geography became a reality. The technics and technologies used in Internet, envolving data communications, with architecture designed to support global communication between computers, becomes the main tool used in the interconnection of thousand geographically distributed sites. With the technology and infrastructure available for an effective communication, also arises the need to ensure that systems are active as long as possible, with a minimum of performance to the services, because the activities in the institutions are dependent upon interaction between computer systems, regardless of the point on the planet they are. This study proposes to model, develop and test a tool to assist in the monitoring of points connected by data communication networks over TCP / IP distributed geographically. The proposed format is to monitor one or more points, displayed on one or more maps with the route of political geographic boundaries of the area served. In short, it is proposed to use the basic tools to test network connectivity in data communications, combined with the concepts of GIS and georeferencing / Mestre

L'utilisation de TCP sur des liens asymétriques entraîne fréquemment des débits plus faibles qu'attendus au point de nuire sensiblement à la qualité de service ressentie par l'utilisateur. Ces baisses de performances peuvent prendre diverses formes parmi lesquelles une forte latence en début de connexion, une sous utilisation de la capacité du lien ou encore des latences excessivement hautes pour l'ensemble de la connexion. Afin de contrer ces effets, plusieurs approches sont possibles, que ce soit de bout-en-bout par des modifications de la pile TCP/IP ou en cœur de réseau avec divers mécanismes d'ordonnancement. L'objectif de cette thèse est d'explorer comment un résultat similaire à celui obtenu par des méthodes d'ordonnancement au goulot d'étranglement peut être obtenu en travaillant de bout-en-bout, c'est à dire là où les ressources de calcul et de mémoire sont les plus abondantes. Ce questionnement est accompagné par une analyse en profondeur des phénomènes causant une dégradation des performances, ainsi que l'évaluation des solutions existantes. Finalement, des solutions nouvelles, en cœur de réseau ainsi que de bout en bout, ont été apportées et testées sur banc d'essai. / Using TCP on asymmetric links may lead to unexpected and significant performance drops, severely degrading user experience. Those performance drops can come in various forms, among which a huge latency at the beginning of a connection, under-utilization of link capacities, or even excessive delays for the whole connection.In order to prevent those effects to happen, various approaches exist, either end-to-end through changes in the TCP/IP stack, or in the network core with a collection of scheduling algorithms.The first goal of this thesis is to explore if and how an end-to-end policy (i.e where CPU and memory resources are the most abundant) can achieve similar results as buffering policies in the core of the network. Secondly, we provide an in-depth analysis of the root cause of the performance drops, and evaluate existing algorithms. Finally, new solutions, both end-to-end and in the core of the network, are brought and tested in real life networks.

Made available in DSpace on 2014-06-11T19:22:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-05-27Bitstream added on 2014-06-13T20:29:02Z : No. of bitstreams: 1 spozito_ds_me_ilha.pdf: 2230007 bytes, checksum: 9240ceb37ed45878d0a4e158290fedf5 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Com a globalização e a evolução tecnológica, a capilaridade das instituições, sejam elas públicas ou privadas, é realidade irreversível. O uso de computadores cada vez mais velozes e com elevada capacidade de armazenamento possibilitou a centralização das informações. Nesse contexto, surge a necessidade de interligar os sistemas computacionais com o objetivo de trocar informações, independentemente da região geográfica. A Internet, utilizando tecnologias de redes de dados, com arquitetura projetada para suportar em nível mundial a comunicação entre computadores, passa a ser a principal ferramenta utilizada na interligação de locais geograficamente distribuídos. Com a tecnologia e infraestrutura disponível para efetivar a comunicação, surge também a necessidade de garantir que os sistemas estejam ativos o maior tempo possível, atendendo a desempenho compatível às atividades desenvolvidas, pois as instituições passam a depender da interação entre os sistemas computacionais, independente do ponto do planeta em que estejam. Este trabalho propõe modelar, desenvolver e realizar ensaios de uma ferramenta que auxilie no monitoramento de pontos interligados por redes de comunicação dados sobre protocolo TCP/IP distribuídos geograficamente. O modelo consiste em monitorar um ou mais pontos, visualizados sobre um mapa com o traçado do perímetro político geográfico da área atendida. Em suma, propõe-se utilizar as ferramentas básicas de teste de conectividade nas redes de comunicação de dados, associadas aos conceitos de georreferenciamento e geoprocessamento / The globalization and technological evolution, allowed the grow of institutions public or private over the entire world with highest capillarity. The development of computers becoming faster and with large storage capacity allowed the centralization of information. In this context the necessity of linking computer systems with the aim to exchange information regardless of geography became a reality. The technics and technologies used in Internet, envolving data communications, with architecture designed to support global communication between computers, becomes the main tool used in the interconnection of thousand geographically distributed sites. With the technology and infrastructure available for an effective communication, also arises the need to ensure that systems are active as long as possible, with a minimum of performance to the services, because the activities in the institutions are dependent upon interaction between computer systems, regardless of the point on the planet they are. This study proposes to model, develop and test a tool to assist in the monitoring of points connected by data communication networks over TCP / IP distributed geographically. The proposed format is to monitor one or more points, displayed on one or more maps with the route of political geographic boundaries of the area served. In short, it is proposed to use the basic tools to test network connectivity in data communications, combined with the concepts of GIS and georeferencing

Esta dissertação descreve os métodos, medidas e análises feitas para otimizar a rede de comunicação de dados do Instituto de Física de São Carlos. As tecnologias e protocolos utilizados na rede são apresentados. Especial atenção é dada a análise do desempenho de VLANs utilizando inicialmente o protocolo LANE no núcleo ATM da rede. Neste caso a rede é composta de switches ATM e ATM-Ethernet. Medidas comparativas foram realizadas com a utilização da tecnologia Fast Ethernet no backbone, que possui uma capacidade de transmissão relativamente próxima da ATM de 155Mbps. Melhores resultados obtidos com a implementação de sub-redes maiores, reduzindo em um numero menor de sub-redes, são discutidos e apresentados. Análises estatísticas baseadas apenas no tempo de resposta da rede são apresentados para avaliar o desempenho das alterações efetuadas nas configurações da rede. Mesmo que o tráfego tenha aumentado muito durante esses anos e que vários serviços tenha sido agregados a esta rede, foi possível adequar o desempenho as novas necessidades beneficiando-se da evolução tecnológica que os equipamentos de rede de dados trouxeram ao IFSC. / This work describes the methods, measures and analyses performed aiming to optimize the data communication network from the Physics Institute of Sao Carlos as well as the technologies and protocols used in the network recently. Special care is given to the analysis of the VLANs performance using, initially, the LANE protocol over ATM which has its core based on pure ATM and ATM-Ethernet switches. Comparative measures had been carried out using a backbone working on a Fast Ethernet technology, which seems to have a very close transmission rate from the ATM 155Mbps. This work also discusses best results acquired with the implementation of larger networks reducing the number of subnetworks, statistical analyses based on time delay of the network in order to evaluate the performance of the changes made on its configuration. Even though the traffic from the Institute has been increased over these years and several services have been added to the network, it was completely possible to adapt the performance to the needs, using the benefits of the technological evolution which the network equipments had brought to the Institute.

This document describes a design procedure of interface between VGA camera and GSM/GPRS modem for displaying JPEG pictures captured by camera on website. Interface is realized by eight-bit micricontroller ATMEL with application written in C language. For picture transfer to server a TCP/IP stack is implemented into modem. The document is divided into two main parts. The first part describes architecture of the system, used components (camera, modem, microcontroller) and electronic circuit design. The second part of the document is focused on the software for the system. Firstly operating system of modem is desribed, OpenAT development environment for modem application design and WIPsoft library, which is used to implement TCP/IP stack. Next is described application for microcontroller which controlls camera and modem. Last part of this document describes server application and web interface.

ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, California / This paper is intended to provide background into networking and IP protocols for non-IT personnel. It is not a study of networking and related protocols, as each of these topics would require a much longer period of time to explain. Addressed are considerations that should be required prior to locking a network design into a specific architecture. The systems available today, for the same cost as a good home PC, are becoming capable of performing critical tasks. It is highly recommended that the personnel who know the most about the data and how it will be used communicate with the personnel that know the network. Failing to explain or understand the networking nomenclature causes considerable wasted time and money. This paper is intended to encourage communications between the data creators and the data movers. We also want to demonstrate how new systems, hardware and software, designed to work with existing network devices used in non–telemetry applications, can make implementing IP in telemetry networks easier.

ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / In today’s world, computer networking has become common place both in industry as well as home, however all networks are not the same! The Telemetry world, like with many industries, has critical design considerations that need to be evaluated when you begin a new system or just adding on to a current infrastructure. This paper is intended to outline needed considerations when planning or implementing a network design in Telemetry Systems. These applications can range from sensor data transport through High Definition/High Speed Video applications.

ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, Nevada / With the emergence of higher bandwidth Ethernet networks on ranges, many ranges are converting their data transport from ATM(Asynchronous Transfer Mode) networks to Ethernet networks. Both networks have their respective advantages and disadvantages, however one reoccurring issue is product interoperability. The RCC (Range Commanders Council) TTG (Telecommunications and Timing Group) created the Telemetry over IP (TMoIP 218-07) solution with input from various ranges and vendors to solve this issue. This specification allows ranges to use different vendors together for Telemetry over Ethernet, based on specific needs at each site. This paper targets those who are thinking about converting from ATM to Ethernet networks.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The CCSDS SCPS FP file transfer performance is compared with that of TCP/IP FTP in a simulated satellite channel environment. The comparison is made as a function of channel bit error rate and forward/return data rates. From these simulations, we see that both protocols work well when the channel error rate is low (below 10^-6) and the SCPS FP generally performs better when the error rate is higher. We also noticed a strong effect on the SCPS FP throughput as a function of forward transmission rate when running unbalanced channel tests.