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Testing the impact of network infrastructure capacity on the performance of Internet access services
Hykš, Matěj ; Šilhavý, Pavel (referee) ; Jeřábek, Jan (advisor)
This master thesis deals with the topic of measuring the transmission capacity of computer networks. It describes the differences between service and link parameters, which are measured using TCP, UDP, ICMP and other protocols. In the last theoretical part, it briefly describes the queueing theory and explains their relevance in today’s computer networks. The result of the work is a custom measurement system that will simulate multi-user access to the electronic communications network, measure its capacity and conform to standards.
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Measurement design in modern packet, transport, and access technologies
Galovič, Dominik ; Michálek, Jakub (referee) ; Škorpil, Vladislav (advisor)
The diploma thesis focuses on the capabilities of the VeEx VePAL Tx300s analyzer and network analysis. In the theoretical part, the thesis focuses on the most common tests used for analyzing network parameters of networks and its devices. Their principles, advantages, and disadvantages are described. The choice of the tests is deliberately selected to match the capabilities of the analyzer itself. Its basic functions are described in this diploma thesis. After understanding the functioning of individual tests and the analyzer itself, two laboratory tasks were created to familiarize potential students, for whom these tasks were designed, with the basic operation of the analyzer and to acquaint them with basic as well as advanced testing of network parameters, whether of active network elements or the laboratory network itself. An addition is the use of the VeEx VePAL tx300 analyzer, which was purchased previously, and the change of an already made laboratory task.
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Open-Source Software Tools for Network Diagnostics
Loffay, Pavol ; Ráb, Jaroslav (referee) ; Matoušek, Petr (advisor)
The aim of this work is to make a research of existing open source tools, which are concerned with the diagnosis of the network transmission in the form of measuring of throughput and other basic parameters. The work is devoted to the construction of methodics for testing and comparing devices between themselves. The result of the work is recommendation to an ordinary customer the right application for measuring of given network transmission parameter.
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Data Profiling Using IPFIX Mediator
Kozubík, Michal ; Bartoš, Václav (referee) ; Kořenek, Jan (advisor)
This thesis deals with the network data profiling using IPFIX mediator. The main task is effective data filtering and configurable profiles management. The profiles management is still not available for IPFIX mediator, which makes analysis of network traffic for users more difficult. Therefore this thesis deals with the design and implementation of configurable profiles management as a plug-in for IPFIX mediator. The plug-in uses profiles hierarchy with filtering rules for data sorting.
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Network service testing with WAN network emulator and load simulators
Kocáb, Marek ; Krajsa, Ondřej (referee) ; Novotný, Vít (advisor)
The main task of this thesis was to explore the requirements of different telecommunications services on the network parameter, that are packet delay, packet loss, throughput, jitter. Make to test network service with WAN network emulator and load simulators. Next focus was to explore TCP congestion avoidance algorithms and focus on their throughput. The purpose of the first chapter is to introduce Quality of Service (QoS) for VoIP, video conversation, streaming audio, streaming video and data. The second chapter are to explore various types of delay, that are created from the sender through network device, transmission media to the recipient. The third chapter is to introduce NetDisturb application. It is application, that can emulate real properties of the data network and incoming traffic affect example packet delay, packet loss, bandwidth limit and so on. The key objectives of the fourth and fifth part is TCP protocol and TCP congestion avoidance algorithms. Hier are to introduce TCP protocol basic properties, congestion avoidance mechanisms and analysis of TCP congestion avoidance algorithms. In the practical part are created two laboratory exercises. First laboratory exercise is designed on the implementation QoS for various types of traffic. Second laboratory exercise is focused on the analysis TCP congestion avoidance algorithms and their throughput.
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Measurement of qualitative parameters in the access network
Kejík, Tomáš ; Slavíček, Karel (referee) ; Grenar, David (advisor)
The theme of this bachelor’s thesis is „Measuring of qualitative parameters in an access network.“ The aim of this paper is a characterization of multimedia broadcasts in access networks and the creation of a functional network generator. The theoretical part of the paper is dedicated to analyzing key broadcasting parameters, which affect the resulting quality of network broadcast. Furthermore, used network protocols that are given for network and multimedia broadcast are analyzed. Simulation is done by using of GNS3 software. After that, transferred data were measured. Side effects affecting the functionality of the resulting transmission were subsequently analyzed. Another part of the paper is the practical part, which is focused on creation of a network generator by using the Bash language and making a script to facilitate turning on the generator for different counts of clients. At the end of the paper, the broadcast parameters were evaluated.
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Hardware Acceleration of Cipher Attack
Okuliar, Adam ; Slaný, Karel (referee) ; Vašíček, Zdeněk (advisor)
Hardware acceleration is often good tool to achieve significantly better performance of processing great ammount of data or of realization of parallel algoritms. Aim of this work is to demonstrate resoluts of using FPGA circuits for implementation exponentially complex algorithm. As example haschosen brute-force attack on WEP cryptographic algorithm with 40-bit long key. Goal of this work is to compare properties and performance of software and hardware implementation of choosen algorithm.
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Multimedia transmissions in wireless networks
Zicha, Karel ; Šedý, Jakub (referee) ; Krkoš, Radko (advisor)
The aim of the thesis is to summarize the qualities of wireless networks operating in the frequency band of 2.4 GHz. In the first part, theoretical knowledge about the architecture of the networks and the comparison of individual standards are presented; the types of interference caused by external devices, including the issue of a hidden node. The possibilities of providing quality services are described following the qWave set. Further, we explore individual access methods and multimedia protocols. The second part comprises the practical verification of this knowledge. The throughput tests of the individual networks were conducted regarding the type of the issue. In the conclusion, the recorded knowledge is described and evaluated.
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Emulator transmission parameters of data networks
Grabovský, Štěpán ; Jeřábek, Jan (referee) ; Zeman, Václav (advisor)
This diploma thesis deals with a development of a network emulator operating in TCP/IP computers networks. This work contains a specification of transmission parameters and an analysis of concurrent systems both proprieties and open-sources. Afterward describes a relalization of the emulator itself. The core of the emulator uses well-known Linux tools tc, netem and iptables. An API of the program is realized by web service and for user interaction has been developed a web user interface. At the end of this work are listed and then discussed measured results of the emulator capabilities.
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Quality of service support in unix-like operating system for communication in WiFi networks
Mizera, Josef ; Komosný, Dan (referee) ; Novotný, Vít (advisor)
Diploma thesis is focused on the supporting of Quality of Services in wireless networks, especially in the Linux operation systems. The topic is connected not only with OS, but also with the wireless standard, which supports QoS in wireless networks called IEEE 802.11e. QoS is needed especially for time-consuming data transfers in real time. The theoretical part deals with the theoretical analysis of the issue of the QoS support. There are described parameters, which occurred in quality of services support. This section also deals with the division of services that are used to transmit data across computer networks. It also describes the QoS support in wireless networks according 802.11e, its implementation and methods of accessing a medium with a without possibility of traffic. This part is followed by a description of QoS support in UNIX operating systems. The chapter describes how is the QoS support designed in these operating systems. There are also characterized concrete tools which are used for control the data flow in the operating systems using Linux. At the end the theoretical part deals with different types of queues and methods used in linux OS. In the practical part of the thesis, there are various designed topologies and scenarios to verify the functionality of QoS support in wireless networks using a Unix system. These chapters show the results of different tests at selected transmission data streams that are sensitive to transmission time. There is also verified cooperation of QoS support between devices operating on the network and data link layers. The output of this work is to design a laboratory exercise for the subject Network Architecture. This exercise is focused on familiarization with the QoS support functionality in wireless networks and in Unix-like operating systems. This chapter also describes the devices and programs that are needed to measure this task. The last part of the chapter describes the procedure for the preparation of the measuring station. For this laboratory task, there is an inserted manual in the annex.
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