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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.
1

Řízení provozu na bezdrátových sítích / Traffic management in wireless networks

Jánoš, Radan January 2011 (has links)
The Master´s thesis „Traffic management in wireless networks“ discusses how to ensure Quality of Service in these networks. A term „traffic management“ is connected mainly with certain restrictions and prioritization of some services and traffics in network. The thesis contains an overview of the most used wireless technologies and describes the approach of these technologies to ensure QoS. Theoretical part of the thesis follows with the definition of general principles of traffic management in IP networks and provides an overview of network parameters used in evaluating the quality of different types of communications services. Practical part is focused on the most widely used wireless technology of standard 802.11 and also on implementation of remote administration system on a small SOHO routers. These systems allow the use of queueing disciplines to manage QoS. Designed and implemented HTB discipline is tested on a real traffic network model.
2

Datainsamling i mininet med ONOS och sFlow : Utveckla laboration kopplad till datainsamling

Pettersson, Josefine January 2022 (has links)
Ett projekt kopplat till SDN och skapande av utbildningsmaterial.
3

Migrering från IPv4 till IPv6 : Prestandamätningar av olika migreringstekniker

Westermark, Martin, Karlsson, Oscar January 2011 (has links)
Antalet tillgängliga IPv4-adresser håller i dagsläget på att ta slut och det ärdärför nödvändigt att hitta en metod för att migrera nätverket till den nyastandarden, IPv6. En migrering kan kräva att de två IP-versionerna måsteanvändas i nätverket simultant, för att de system som är beroende av nätverketska vara tillgängliga. Syftet med arbetet var att undersöka prestandani de olika migreringsteknikerna, samt att få fram vilka tekniker som är attföredra. Med hjälp av två scenarion, uppsatta i labbmiljö, testades migreringsteknikernasprestanda med verktyget Iperf. 6to4 och GRE testades iden ena miljön samt NAT64 och Teredo i den andra miljön. De nätverksegenskapersom analyserades var throughput, jitter samt packet loss. Resultatenvisade på att 6to4 och GRE är näst intill jämlika men att 6to4 haraningen bättre throughput än GRE. Större skillnad var det mellan NAT64och Teredo, där Teredo kunde uppmätas till en mycket högre hastighet medUDP-trafik än NAT64. När TCP användes var dock NAT64 något snabbareän Teredo. / The number of usable IPv4 addresses is in the current situation sufferingfrom exhaustion and it is therefore necessary to find a way to migrate thenetwork to the new standard, IPv6. A migration may require that the two IPversions must be run on the network simultaneously, to make sure that systemsthat are dependent on the network are running stable. The purpose ofthis study was to examine the performance of the different migration techniques,and find out which techniques are preferred. With the help of twoscenarios that were used in a test bed, a performance test was done usingthe Iperf tool. 6to4 and GRE were tested in one environment and NAT64and Teredo in the other environment. The network properties analyzed werethroughput, jitter and packet loss. The results showed that the 6to4 and GREare almost equally balanced but 6to4 has slightly better throughput thanGRE. A much more notable difference could be seen between NAT64 andTeredo, were Teredo was measured with a much higher transmission rate ofUDP traffic than NAT64. However, when TCP was used, NAT64 wasslightly faster than Teredo.
4

Portabel nätverksövervakning och prestandatest

Bengtsson, Thom, Snäll, Anton January 2020 (has links)
This work has been done as an assignment from CGI with the ambition to find an opensource program that provides both network monitoring and performance testing. Theprogram should be able to run on a portable server or other machine, to allow for datagathering of one network one day and of another network the next day. Due to the currentstate of society all work is done *remotely*, restricting tests to only be performed onsmaller private networks. Much time is put into research to find the programs that intheory would work for the purpose. It's quickly revealed that with open source as ademand, a single program is not an option, thus the search is expanded. Tests areperformed where the programs are graded by useability and functions that facilitateredeployment of the server between network sites. The results for network monitoring arethe programs OpenNMS Horizon and NetXMS, which both lived up to the demands. Theprogram chosen for performance testing is Flent, which among others combines Iperf andNetperf in its tests and presents the results in graphs.The limited time affected ouropportunities to test all the programs we came across and the current pandemic limitedour opportunities to test our chosen programs to a greater extent.The goal of finding onesolution was not accomplished and instead resulted in two separate pieces of software.These are found to accomplish their respective goals.
5

Uppdatering av IT-stöd hos Markbyggarna AB

Zakharina, Tatiana January 2019 (has links)
Markbyggarna AB är ett företag som huvudsakligen utför markarbete och maskintjänster. Företagets IT-system är formad för att stödja typiskt kontorsarbete. Projektet inriktades på att hjälpa företaget effektivisera det befintliga systemet och i större omfattning nyttja kostnadsfria alternativ som finns tillgängliga i dagens läge. Arbetet startade med definiering utav systemets avgörande aspekter. För hårdvarorna ställdes krav på CPUs, RAMs och hårddiskens belastning. För mjukvaror definierades funktioner som systemet bör innehava. För trådburen och trådlös nätverk definierades krav på internetanslutning. Efteråt samlades informationen om prestanda i det befintliga systemet med hjälpa av olika övervakningssystem, verktyg och intervjuer. PGRG tillämpades för hårdvarornas övervakning. För nätverksövervakning skapades ett eget övervakningssystem med stöd av de kommandobaserade verktygen Iperf, Speedtest-cli och verktyget Vistumbler. Övervakningsresultaten jämfördes med de önskade egenskaperna och skillnaden mellan dessa två utgjorde underlag för förändringsarbete även med beställarens önskemål i åtanke. Såldes gick den praktiska delen av projektet bland annat på att trådlös signal förstärktes genom installation av AP, introduktion av nya applikationer, en anslutning till företagets PC hemifrån samt skapades system för säkerhetskopiering. Även har en rad andra säkerhetsåtgärder vidtagits. För att kunna utvärdera det genomförda arbetet övervakades det trådlösa nätverket på nytt. Dessa förändringar har gjort att IT-systemet blivit säkrare, med bättre presterande nätverk. Flexibiliteten och funktionaliteten har också ökat. Totalt gick projektet på 1660 kr för inköp av hårda varor. Det gick att täcka de flesta av företagets behov med kostnadsfria mjuka varor.
6

Supervision de la qualité des liens d'un réseau local domestique hybride

OLVERA IRIGOYEN, Oscar 20 December 2012 (has links) (PDF)
Home networks are evolving vigorously and are also becoming more and more heterogeneous and complex. Home networks contain new services and numerous devices with wired and wireless links. At the same time, users demand high levels of quality of service for many new applications. Hence, the supervision of links quality tends to be mandatory in emergent home networks, to trigger QoS mechanisms. In this context, this dissertation proposes the utilization of the available bandwidth as a performance indicator in hybrid home networks (e.g. for remote service-evaluation, diagnosis and fault detection) and as link-state metric for a number of QoS mechanisms (e.g., admission control, path selection and load balancing). In this dissertation, we firstly explain why available bandwidth probing is a fundamental tool in the new QoS architectures for hybrid home networks and we explore different use cases. We investigate the networking constraints that affect bandwidth probing in hybrid home networks. We explain why most tools to measure available bandwidth on Internet paths are not very efficient on home networks. We make a taxonomic study of a number of state-of-the-art probing techniques and probing tools for available bandwidth. At that aim, we propose a functional framework, called Metrics Profile Capture Filter and Feedback (MPCFF). Based on these studies, we choose Iperf in TCP mode as an attractive tool to estimate available bandwidth. Then, we conduct a performance evaluation on an experimental test bed, to compare Iperf in lightweight TCP-mode vs. various state-of-the-art tools (Wbest, Pathchirp, Pathload and IGI/PTR). We show that Iperf in lightweight TCP mode is superior in terms of accuracy and speed of convergence. Finally, we integrate Iperf in lightweight TCP mode into a path selection protocol using the Inter-MAC software (developed in the Omega European project). We show, on a test bed, how Iperf in lightweight TCP mode enhances the Inter-MAC path selection by eliminating performance deterioration due to time-varying capacity links. Our results show that Iperf in lightweight TCP mode, accurately, triggers path selection and load balancing mechanisms, to adapt the network resources to the strong degradation of WiFi and PLC links. Available bandwidth probing detects and helps to control real-time deviations of the quality of experience, associated of sensitive applications. At the same time, available-bandwidth probing helps the service provider to isolate failures and to monitor the end-to-end residential service, on demand or on long-term periodicity basis.
7

Avaliação da experiência do usuário com base na arbitragem de parâmetros de QoS em fluxo multimídia, em cenários com roteadores Cisco e placa NetFPGA

Jacaúna, Rafael Sant'Ana 19 August 2016 (has links)
A streaming video has features that differs from other streams: the occupation of large amount of bandwidth, and the possible variation of scenes with consequent increase (or decrease) in amount of bytes transmitted. Applications for video streaming transmission (YouTube, Vimeo, Netflix, Telecine Play, etc.) have aroused the interest of the scientific community regarding the behavior of networks. Our proposal is to measure, from a video stream, the user experience (QoE) based on arbitration QoS parameters in a controlled environment which use NetFPGA. The results of the experiments has shown the efficacy of TCP over UDP, which at the stage of choosing the most appropriate protocol for testing, showed to be ineffective to the Gigabit Ethernet rate. These experiments occurred in distinct physical topologies; only Cisco routers, with and without QoS, with and without injection of traffic generated by software iperf in the network, and using NetFPGA board set to router only with and without traffic via iperf, once the design developed to make the board work as a router does not allow QoS settings. in these scenarios, there was the need to start the client running at different times, setting their respective caches different networks so that did not coincide scenes, avoiding high bandwidth peaks in stretches with a lot of movement. / Um streaming de vídeo tem características que o difere dos demais fluxos: a ocupação de grande quantidade de banda, e a possíveis variações de cenas com consequente aumento (ou diminuição) na quantidade dos bytes transmitidos. Aplicações para transmissão de streaming de vídeo (YouTube, Vimeo, NetFlix, Telecine Play, e etc.) tem despertado o interesse da comunidade científica quanto ao comportamento das redes. Nossa proposta é correlacionar, a partir de um fluxo de vídeo, a experiência do usuário com base na arbitragem de parâmetros de QoS em ambiente controlado. O resultado dos experimentos demonstrou a eficácia do protocolo TCP sobre o UDP, que na fase da escolha do protocolo mais adequado para os testes, mostrou-se ineficiente até a taxa Gigabit Ethernet. Esses experimentos ocorreram em topologias físicas distintas; apenas com roteadores Cisco, com e sem QoS, tendo ou não injeção de tráfego gerado pelo software iPerf na rede, e usando a placa NetFPGA no modo router, apenas com e sem tráfego via iPerf, uma vez que o projeto desenvolvido para fazer a placa atuar como roteador não permite configurações de QoS. Nesses cenários, constatou-se a necessidade de iniciar a execução dos clientes em momentos diferentes, configurando seus respectivos caches de redes diferentes, para que não coincidissem as cenas, evitando altos picos de banda em trechos com muita movimentação.
8

Bezdrátový optický spoj / Free-Space Optics data link

Šála, Jakub January 2010 (has links)
In this thesis, shows a current issue for free space optics, limiting their use in practice with regard to the availability and reliability. They conducted measurements on wireless optical links and the observed values is calculated by the availability of the connection. Subsequently, measurements are performed on alternate versions of wireless and copper connections. Observed values were compared with a wireless optical link. It is made of optical design of wireless connections at home.

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