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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.
781

Implementação de um sistema de iniciação de sessão multimidia para a plataforma Linux

Santos Filho, Francisco Helder Candido dos 06 August 2018 (has links)
Orientador: Luis Geraldo Pedroso Meloni / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-06T10:38:34Z (GMT). No. of bitstreams: 1 SantosFilho_FranciscoHelderCandidodos_M.pdf: 1367598 bytes, checksum: 0368aefcf26bd8943f28cd7e780c1593 (MD5) Previous issue date: 2005 / Resumo: Esta dissertação trata da modelagem e desenvolvimento de um sistema de voz sobre IP (VoIP) para multiplataforma, utilizando o protocolo SIP para o estabelecimento de sessão. O protocolo de iniciação de sessão (SIP), utilizado no desenvolvimento deste sistema, é um protocolo de sinalização e controle de chamadas entre dois ou mais participantes, que tem ganhado uma grande aceitação por parte da comunidade de telecomunicações. O sistema RT-DSPhone foi desenvolvido para o Linux e o µClinux, que é um sistema operacional baseado no Linux para dispositivo embarcado. O sistema aqui idealizado RT-DSPhone, foi desenvolvido usando-se a linguagem C, juntamente com as APIs da biblioteca oSIP e ferramentas para desenvolvimento em sistemas embarcados, a _m de possibilitar a criação de um sistema de comunicação flexível e robusto. Também é descrito a arquitetura e o funcionamento do protocolo SIP, utilizado para o desenvolvimento da sinalização do RT-DSPhone. É ainda detalhado o desenvolvimento do sistema que permite a criação, controle e finalização de sessões multimídia entre dois participantes através do protocolo SIP. Por fim, são realizados testes de modo a se avaliar a capacidade de interoperabilidade e análise de desempenho do sistema implementado / Abstract: This dissertation deals with modeling and development of Voice over IP (VoIP) system for multiplatform, using the SIP protocol to accomplish the session. The Session Initiation Protocol (SIP), used in the development of this system, is a protocol for creating, modifying and terminating calls between two or more participants, and it has received great support of the communications community. The RT-DSPhone system was developed for Linux and µClinux, which is a operating system for embedded system. The RT-DSPhone system was developed using the C language, the APIs of oSIP library, and tools for embedded systems, for the creation of a robust and flexible communication system. It is also described the architecture and operation of the SIP protocol used in the development of the RT-DSPhone signaling. The development of a system that allows the creation, control and finalization of multimedia sessions between two users through the SIP protocol is also detailed. Finally, some tests are carried out in order to evaluate the interoperability capacity of the developed system / Mestrado / Engenharia Eletrica / Mestre em Engenharia Elétrica
782

Protocolos TCP/IP para sistemas embarcados

Pereira, Felipe Massia 03 August 2018 (has links)
Orientador : Celio Cardoso Guimarães / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica / Made available in DSpace on 2018-08-03T14:41:09Z (GMT). No. of bitstreams: 1 Pereira_FelipeMassia_M.pdf: 1232996 bytes, checksum: 6534b5a29c260209081ce1c6168f6575 (MD5) Previous issue date: 2003 / Mestrado
783

Simulador de redes orientado a eventos para o sistema operacional Linux

Kulzer, Ricardo Luis 03 August 2018 (has links)
Orientador: Leonardo de Souza Mendes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-03T17:39:40Z (GMT). No. of bitstreams: 1 Kulzer_RicardoLuis_M.pdf: 562295 bytes, checksum: 8bee2e573b06f6100bd5fc8b521b9cd6 (MD5) Previous issue date: 2003 / Mestrado
784

Analise de segurança em aplicações que utilizam plataformas UNIX e MS-Windows como clientes e servidores

Curti, João Carlos 31 August 2004 (has links)
Orientador: Paulo Licio de Geus / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-04T02:27:03Z (GMT). No. of bitstreams: 1 Curti_JoaoCarlos_M.pdf: 5600051 bytes, checksum: 734272d04475d17d8c1a5c95ddafa0d7 (MD5) Previous issue date: 2004 / Resumo: Nos últimos anos temos acompanhado e assistido as profundas mudanças na área de tecnologia, tanto em software quanto em hardware, permitindo que os computadores se popularizassem e que aplicações pudessem ser criadas para atender a crescente demanda deste novo mercado. Infelizmente a adição dos mecanismos para prover segurança a estas aplicações não acompanhou o ritmo deste crescimento. Soluções foram adotadas para minimizar a exposição dos dados, uma vez que, com a utilização de computadores em rede, existe a necessidade do tráfego de informações por estes canais novos e de certo modo pouco explorados --- para não dizer pouco conhecidos --- para a maioria dos programadores. Da diversidade de ambientes operacionais, o mercado e o marketing das empresas selecionaram duas plataformas distintas; uma proprietária e fechada, representada basicamente pela Microsoft e outra representada pelas variações de UNIX, sejam elas de código aberto (FreeBSD, Linux, OpenBSD e outros), ou proprietárias (HP Tru64Unix, SunOs e outros). Sendo assim as informações tratadas pelas aplicações estão sujeitas, além de às suas próprias falhas, também às vulnerabilidades do Sistema Operacional onde são desenvolvidas e executadas. Em vista destes fatos, o foco desta dissertação é apresentar como é possível a implantação de produtos de software comerciais do tipo ERP1, independentemente da plataforma adotada pela empresa/instituição para execução de suas aplicações, provendo segurança nos canais de comunicação. Utiliza-se para isso ferramentas proprietárias ou nativas do próprio Sistema Operacional, bem como buscando de software livre para aplicações do tipo Cliente/Servidor e WEB / Abstract: In the last years we have followed and watched deep changes in technology, as much in software as in hardware, allowing for computers to get popular and for applications to be created to serve the growing demand of this new market. Unfortunately the addition of mechanisms to supply security to applications not follow the pace of this growth; solutions were adopted to minimize data exposure, since, with the use of computer networks, there is a need for information flow through these new, somehow unexplored and even unknown channels for the majority of programmers. From the diversity of operating environments, the market and the companies' marketing departments selected two distinct platforms: a proprietary and closed one, represented basically by Microsoft and another, represented by the variations of UNIX, be they of open code nature (FreeBSD, Linux, OpenBSD ele), or of proprietary nature (HP Tru64Unix, SunOS ele). As such, the information dealt with by applications are subject not only to their own vulnerabilities, but also to those of the operating system for which they were developed. In view of these facts, the focus of this dissertation is to show how it is possible, mainly for commercial implementation of ERP software and independently from the platform or operating system used, to supply security to the communication channels by using either free or native proprietary tools of the operating system itself, both to WEB as well as to other client/server applications / Mestrado / Redes de Computadores / Mestre em Computação
785

Using Network Attached Storage for IP-Surveillance : Bottleneck analysis and developing a method for testing Network Attached Storage performance for IP-surveillance

Nymberg, Joakim January 2013 (has links)
IP-surveillance systems are surveillance systems designed to send video and audio over IP-networks, to be able to function a typical system consist of IP-cameras to record footage, a client to view footage and recordings, network hardware to send the data, protocols to administer storage and viewing operations and last but not least a location to store the captured data. One of the options for storing surveillance video is to use a Network Attached Storage. Axis has received customer cases reporting lost footage and cameras losing their connection when using NAS-devices as storage in IP-surveillance systems. This thesis aims to investigate what a NAS is and how it interacts with cameras in an IP-surveillance environment by analyzing the protocols and components being used and by performing experiments to locate the system bottleneck causing these problems. After concluding that the hard disk drive was the bottleneck because of the overload imposed on the other components by the incoming data traffic and how data is moved and temporarily stored in a system. Recommendations of possible ways to remedy these problems were suggested with the proposed problem of solving the bottleneck problem was to add more disks to improve performance, this was the second aim of the thesis, which sadly was not possible because of the 2-bay NAS systems being used in the tests. The third and final aim was to establish and develop method guidelines for testing NAS-systems. This was done by using previous research in the area and using data encountered when trying to locate the bottleneck.
786

Mobile IP handover delay reduction using seamless handover architecture

Aldalaty, Khalid January 2009 (has links)
Seamless communication is becoming the main aspect for the next generation of the mobile and wireless networks. Roaming among multiple wireless access networks connected together through one IP core makes the mobility support for the internet is very critical and more important research topics nowadays. Mobile IP is one of the most successful solutions for the mobility support in the IP based networks, but it has poor performance in term of handover delay. Many improvements have been done to reduce the handover delay, which result in two new standards: the Hierarchical MIP (HMIP) and the Fast MIP (FMIP), but the delay still does not match the seamless handover requirements. Finally Seamless MIP (S-MIP) has been suggested by many work groups, which combine between an intelligent handover algorithm and a movement tracking scheme. In This thesis, we show the handover delay reduction approaches, specifically the Seamless Mobile IP. The thesis studies the effects of the S-MIP in the handover delay and the network performance as well. A simulation study takes place to compare between the standard MIP and the new suggested S-MIP protocol in term of handover delay, packet loss and bandwidth requirement. The thesis concludes with the analyzing of the simulation results, evaluating the S-MIP performance and finally gives some suggestions for the future work. / 0046704623257
787

IPv6 : Inte längre frågan OM och inte så mycket NÄR utan snarare HUR! / IPv6 : no longer a question of IF and less a question of WHEN but rather HOW!

Atilmis, Birkan, Hoff, Linda January 2001 (has links)
Problemområde: Idag har Internet blivit var mans egendom. Detta innebär tyvärr en hel del problem. Det tydligaste vi står inför idag är att IP-adresserna håller på att ta slut. För att bli av med problemet används olika temporära lösningar ("lappningsteknik") men även en permanent lösning utvecklas, nämligen Ipv6 (Internet Protocol version 6).Det nya protokollet löser adressbristen men har även många andra funktioner så som säkerhet och bättre routinglösningar. Vi ställde oss då frågan varför har ingen övergång skett trots dessa fördelar. Frågeställning: Var i övergången mellan IPv4 och IPv6 står vi idag? Varför har inte övergången mellan IPv4 och IPv6 redan skett? Vilka är de största anledningarna och vilka fler möjliga finns det? Slutsats: Arbetet visar att tiden för en övergång ännu inte är inne. Huvudanledningarna är att det saknas produkter och en allmän anledning för en migration.
788

En studie av inbyggda brandväggar : Microsoft XP och Red Hat Linux / A study of built-in firewalls : Microsoft XP and Red Hat Linux

Ahlgren, Johan, Karlsson, Robert January 2003 (has links)
Detta kandidatarbete utreder hur väl två operativsystems inbyggda brandväggar fungerar i symbios med en användares vanligaste tjänsteutnyttjande på Internet, samt att se hur likartade de är i sitt skydd från hot. De två operativsystemen som vi utgick ifrån var Microsoft Windows XP samt Red Hat Linux 8.0. Den hypotes vi arbetat kring lyder enligt följande: De två inbyggda brandväggarna är i stort likartade rörande skydd från hot på Internet och uppfyller användarnas tjänsteutnyttjande. De metoder vi använt, för att svara på vår frågeställning, har delats upp i ett funktionalitetstest och ett säkerhetstest. I funktionalitetstestet provades de vanligaste Internettjänsterna med den inbyggda brandväggen och ifall det uppstod några komplikationer eller ej. De två inbyggda brandväggarna genom gick i säkerhetstestet skannings- och svaghetskontroll via ett flertal verktyg. Genom resultatet kan vi konstatera att de inbyggda brandväggarna klarar av de vanligaste tjänsterna på Internet, men att en skillnad föreligger hos dem vad gäller exponeringen ut mot Internet. Windows XP ligger helt osynligt utåt, medan Red Hats inbyggda brandvägg avslöjar en mängd information om värddatorn, som kan komma att användas i illvilliga syften. Slutsatsen blev att vi avslutningsvis falsifierade vår hypotes då de två inbyggda brandväggarna ej var jämlika i sitt skydd mot yttre hot på Internet.
789

Architecture for IMS Security to Mobile:Focusing on Artificial Immune System and Mobile Agents Integration / English to Swedish

Chalamalasetty, Kalyani January 2009 (has links)
The IP Multimedia Subsystem (IMS) is an open IP based service infrastructure that enables an easy deployment of new rich multimedia services mixing voice and data. The IMS is an overlay network on top of IP that uses SIP as the primary signaling mechanism. As an emerging technology, the SIP standard will certainly be the target of Denial of Service (DoS) attacks and consequently IMS will also inherit this problem. The objective of proposed architecture for IMS is to cram the potential attacks and security threats to IP Multimedia Subsystem (IMS) and explore the security solutions developed by 3GPP. This research work incorporates the ideas of immune system and multiagent architecture that is capable of detecting, identifying and recovering from an attack. The proposed architecture protects IMS core components i.e. P-CSCF (Proxy- Call Session Control Function), I-CSCF (Interrogating-Call Session Control Function), S-CSCF (Serving Call Session Control Function) and HSS (Home Subscriber Server) from external and internal threats like eavesdropping, SQL injection and denial-ofservice (DoS) attacks. In the first level i.e. CPU under normal load all incoming and out going messages were investigated to detect and prevent SQL injection. Second level considers Denial of Service (DOS) attacks when CPU load exceeds threshold limit. Proposed architecture is designed and evaluated by using an approach called Architecture Tradeoff Analysis Method (ATAM). The results obtained confirm consistency of the architecture. / kalyani-0046737527800
790

Efficient content distribution in IPTV environments

Galijasevic, Mirza, Liedgren, Carl January 2008 (has links)
Existing VoD solutions often rely on unicast to distribute content, which leads to a higher load on the VoD server as more nodes become interested in the content. In such case, P2P is an alternative way of distributing content since it makes better use of available resources in the network. In this report, several P2P structures are evaluated from an operators point of view. We believe BitTorrent is the most adequate protocol for a P2P solution in IPTV environments. Two BitTorrent clients have been implemented on an IP-STB as proof of concept to find out whether P2P is suited for IPTV environments. Several tests were conducted to evaluate the performance of both clients and to see if they were able to reach a sufficient throughput on the IP-STB. Based upon the tests and the overall impressions, we are convinced that this particular P2P protocol is well suited for IPTV environments. Hopefully, a client developed from scratch for the IP-STB will offer even greater characteristics. Further, we have studied how to share recorded content among IP-STBs. Such a design would probably have many similarities to BitTorrent since a central node needs to keep track of content; the IP-STBs take care of the rest. The report also brings up whether BitTorrent is suitable for streaming. We believe that the necessary changes required to obtain such functionality will disrupt the strengths of BitTorrent. Some alternative solutions are presented where BitTorrent has been extended with additional modules, such as a server.

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