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Virtual servers with Fedora operating system
Gajdušek, Ondřej ; Jeřábek, Jan (referee) ; Komosný, Dan (advisor)
This thesis deals with the PlanetLab Server Manager application whose aim is to simplify application development within the experimental distributed network PlanetLab. Thesis presents the PlanetLab network and describes its infrastructure. Application PlanetLab Server Manager, shortly abbreviated as plbmng, is described, its current state is evaluated and the existing functionality is presented to the reader. Further work focuses mainly on the implementation of the new functionality that is a software distribution and job scheduling to run the software at the specified time. The last part of the work presents an experiment that demonstrates a real-life usage of the newly added functionality. Work results are published at the public repository on the GitLab platform. The application was published at the package index for Python Packages - PyPI.
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Monitoring Application for Multicast sessions
Kopecký, Martin ; Komosný, Dan (referee) ; Šimek, Milan (advisor)
This work deals with a monitoring application for multicast sessions. The general aim is to develop the application for monitoring multicast sessions from network elements of a laboratory computer network. The first part describes possibilities of monitoring computer networks in terms of monitoring techniques and protocols. The second part contains a topology of the laboratory computer network and several basic commands for setting of the multicast in Cisco IOS. The third part is devoted to the developed application for monitoring the multicast in Java language. The last part describes the testing on an actual multicast network and an example of such testing is stated there.
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Remote connection to virtualized operating system
Veselý, Marek ; Červenka, Vladimír (referee) ; Komosný, Dan (advisor)
The thesis is focused on the new IT trend – virtualization. Below are described the types of virtualization, as well as different implementations of it. In the following chapters there will be described the TCP and ICMP protocols, as well as the SSH services. The last part of this work is dedicated to measurements where there will be highlighted the advantages and disadvantages of virtualization.
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Reference Nodes Selection for Anchor-Free Localization in Wireless Sensor Networks
Šimek, Milan ; Makáň, Florian (referee) ; Diviš, Zdeněk (referee) ; Komosný, Dan (advisor)
Dizertační práce se zabývá návrhem nového bezkotevního lokalizačního algoritmu sloužícího pro výpočet pozice uzlů v bezdrátových senzorových sítích. Provedené studie ukázaly, že dosavadní bezkotevní lokalizační algoritmy, pracující v paralelním režimu, dosahují malých lokalizačních chyb. Jejich nevýhodou ovšem je, že při sestavení množiny referenčních uzlu spotřebovávají daleko větší množství energie než algoritmy pracující v inkrementálním režimu. Paralelní lokalizační algoritmy využívají pro určení pozice referenční uzly nacházející se na protilehlých hranách bezdrátové sítě. Nový lokalizační algoritmus označený jako BRL (Boundary Recognition aided Localization) je založen na myšlence decentralizovaně detekovat uzly ležící na hranici síti a pouze z této množiny vybrat potřebný počet referenčních uzlu. Pomocí navrženého přístupu lze znažně snížit množství energie spotřebované v průběhu procesu výběru referenčních uzlů v senzorovém poli. Dalším přínosem ke snížení energetických nároku a zároveň zachování nízké lokalizační chyby je využití procesu multilaterace se třemi, eventuálně čtyřmi referenčními body. V rámci práce byly provedeny simulace několika dílčích algoritmu a jejich funkčnost byla ověřena experimentálně v reálné senzorové síti. Navržený algoritmus BRL byl porovnán z hlediska lokalizační chyby a počtu zpracovaných paketů s několika známými lokalizačními algoritmy. Výsledky simulací dokázaly, že navržený algoritmus představuje efektivní řešení pro přesnou a zároveň nízkoenergetickou lokalizaci uzlů v bezdrátových senzorových sítích.
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Visualization of relations between computers in the Internet
Cimbálek, Přemysl ; Malý, Jan (referee) ; Komosný, Dan (advisor)
Internet Protocol Television (IPTV) transmits the television signal over the TCP/IP family of protocols. Its advantages are for example that the transmitting is not only one-way as in the “classical” TV broadcasting, but it can provide feedback such as interactivity. There are also some problems which avoids development, for example low channel capacity of access networks. That is why new methods , for example how to get more efficiency in IPTV transmission, are proposed. The main task of this diploma thesis is to visualize tree structure of relations between nodes in the network, based on understanding of principles of the hierarchical summarization and IPTV transmitting. The nodes in the tree structure provide computing and summarizing of the data in back-way channel. There is the data from the end users in this channel. In the first part of this diploma thesis there is explained the principle of IPTV and its differences as compared with classical TV broadcasting. The part is also aimed for the supported services, advantages and disadvantages. There is explained the compressing data with the MPEG-2 and MPEG-4 standards and problems with transport networks called “last mile problem.” To transmitting data IPTV uses Source Specific Multicast – every user connects to the multicast session with requested TV program. Feedback is provided by unicast. Feedback network uses the hierarchical summarization principle to reduce the data. This problem, connected with RTP, RTCP and TTP protocols, is in the work described as well. There is an international experimental network called PlanetLab mentioned in theoretical part of this work. Proposed structure of new protocol and applications including the visualization for IPTV broadcast, is tested in that network. In the practical part of this work there are discussed possibilities and methods for the visualization and data storage. Because of high availability and flexibility, there were chosen web technologies, such as MySQL for data storage. The tree model is executed by Java. The visualization is solved by web technologies, source code for visualization is dynamically generated by scripts in JSP (Java Server Pages). Graphical output is provided by the vector format SVG (Scalable Vector Graphics) which is created for graphical expression on the internet and in the mobile phones. There were created interactive web application thanks its ability to cooperation with Javascript technology. This application visualizes relation-tree structure of nodes. In this work there are explained basics of all used technologies, there are also given reasons for chosen methods and formats. Examples and interesting parts of solution are mentioned as well.
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New functions of client application for DNS protocol for lectures
Ramosová, Patrícia ; Komosný, Dan (referee) ; Jeřábek, Jan (advisor)
The aim of this Master thesis entitled New functions of client application for DNS protocol for lectures is to gain understanding of domain name translation protocols, examine the existing clientDNS application, its source codes and compare it with similar existing tools, such as DNS Benchmark, Nslookup and Dig. Based on the performed analysis, new functionality was designed and various errors that the original application contained were identified. After implementing the proposed features and minor improvements, the new version of the DNS client app has been properly tested. The main innovations of the application consist of new modules for DNS over TLS and Link-Local Multicast Name Resolution protocols, and a new module for Mass testing of DNS servers and domain names. Minor improvements consist mainly of a new graphical interface adapted for small and large screens, multi-thread architecture, automatic translation and much more.
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Analysis of the communication path attributes for IP geolocation
Rajnoha, Martin ; Komosný, Dan (referee) ; Balej, Jiří (advisor)
The aim of this thesis was to study current resources to find location of stations in the network Internet, mainly active methods that are based on delay measurements. Describe origin of the delay and its parts. Next create an application that is able remotely measure the delay between stations and convert this delay to distance. Aplication calculate geographic position of station on based this distances. For measurement was used experimental network PlanetLab.
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Analysis of web server hosting
Ilgner, Petr ; Kubánková, Anna (referee) ; Komosný, Dan (advisor)
Master thesis deals with the problematics of webpages hosting in the Czech Republic. The goal of the thesis is to design a procedure and to implement an application for automated determination of whether a particular website is operated on a third party server or an own server of the organization or the individual. The thesis is divided into two main parts. The first part of the thesis lays a theoretical base concerning principals, protocols and services which are necessary for providing availability of the webpages with special attention to the specifics of the Czech internet environment. In the practical part there are several approaches to the analysis of the obtained data proposed. On that basis there is designed and in the form of the detection application implemented an algorithm which goal is to determine whether the submitted webpages are placed on a shared server and to collect the information about their hosting. In the last part of the thesis the application runs based on the created database of webservers organized by the categories of the webserver operators. In this analytic part the obtained output information about these webservers hosting are processed and presented together with the relevant context concerning the hosting of these webpages in the Czech Republic.
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Measurements in an 802.11n radio network with hidden nodes
Vágner, Adam ; Komosný, Dan (referee) ; Münster, Petr (advisor)
The current large concentration of wireless networks brings new horizons, but also new concerns. Failure to follow basic rules may produce far-reaching problems that could make more wrinkles to all affected managers and administrators. The aim of this thesis was to measure and compare the radio parameters of selected products and how they behave in neighboring interference and the speed they have while there are hidden nodes. The resulting values were measured in the laboratory network Wificolab and compared with the various support protocols. Possible effects on the specific situation are also analyzed in this thesis.
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Use of optical cable properties for geolocation in the Internet
Chmelař, Jakub ; Verner, Lukáš (referee) ; Komosný, Dan (advisor)
This thesis deals with the IP geolocation which estimates the geographic location of hosts in the Internet network. The knowledge of geographic location can be used both for targeting specific services and information, such as advertisement or weather forecast, and for better utilization of transport network because it is possible to serve content from sources which are located closer to client. The main topic of this thesis is the Speed of Internet geolocation method (SOI), which is an active method based on measurement of latency in network. The theoretical part of the thesis explains how to perform these measurements and briefly describes a few more active geolocation methods. The practical part includes full description of SOI implementation created using Python programming language. This implementation was subsequently used to accomplish a sequence of measurements which allowed accuracy comparison with other geolocation methods. The final part of this thesis evaluates results of these measurements and offers a few possible changes which could improve accuracy of described implementation.
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