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Measurement of influence of network impairments on VoIP call quality
Zelenay, Martin ; Krkoš, Radko (referee) ; Šilhavý, Pavel (advisor)
This work explores, analyzes and rates influence of network impairments on VoIP traffic. It describes how voice over IP is carried according to standards. There are described concepts and basics of VoIP networks with orientation on facts necessary to understand analyzed actions and measurements in theoretical part. In practical part, there is described realization of tests according to instructions with orientation on initial checking of devices and rating models and then measurement of influence of network impairments on quality of calls with use of these devices and Opensource PBX Asterisk.
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Mobile IP in MANETs
Raška, Martin ; Hošek, Jiří (referee) ; Skořepa, Michal (advisor)
This thesis discuss about the problem with mobility of stations in IP networks, concretely protocol Mobile IP and about the problems with this protocol in MANET networks, with the scope on Motorola MESH. First part is about design integration of protocol Mobile IP in this networks with usage Tropos 5210 MetroMesh routers and Cisco components (router, switch) to design and configure wireless MESH network, than connect this network with Cisco components and try to implement Mobile IP into this network. Second part is about design and configure wireless network from Cisco Wireless Access Points and about succesfully implementation of Mobile IP protocol into this network. In the last part is some tests of the function and quality of this topology.
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Laboratory of Quality of Service
Eltahir Ahmadon, Ahmed ; Kolka, Zdeněk (referee) ; Polívka, Michal (advisor)
Abstrakt Bakalářská práce se zabývá problematiku IP telefonie, emulace sítě a kvalitou službou (QoS). Kapitol 2 pojednává o model TCP/IP a OSI, síťových protokolech (IP, TCP, UDP) a o protokolu SIP. Kapitole 3 se zabývá problematikou QoS, definicí QoS, QoS ve službách s reálným časem, parametry a způsoby změření kvality hlasu – subjektivními a objektivními testy. Na základě získaných poznatků byla navržena laboratoř kvality služby. Laboratoř je zaměřena na testování kodeků z hlediska kvality přenášeného zvuku, s ohledem na šířku pásma a ztrátovost paketů. Laboratoř kvality služby byla navržena tak, aby byly splněny požadavky na subjektivní testy uvedené v kapitole 3. 4. Návrh laboratoře Schéma navržené laboratoř je zachyceno na obr. 4.1. Návrh je složen ze čtyř hlavních částí – Dvou softwarových IP telefonů (XLite), síťového emulátoru (WANem Wide Area Network emulator), a SIP ústředny (3CX Phone System pro Windows od 3CX Ltd). Sestavování spojení prbíhá podle stejného schématu viz obr. 4.1. Oba koncové uzly jsou připojeny přes emulátor WANem. Počítač, na kterém je emulátor instalován má dvě síťová rozhraní. PC1, resp. PC2 s WANem tvoří lokální síť 1 (LAN1), resp. lokální síť 2 (LAN2). Pakety prochází z jednoho uzlu do druhého přes WANem. WANem emuluje chování skutečné WAN sítě, umožňuje provádět v laboratorním prostředí testy na síti s přesně definovanými parametry. Návrh celé laboratoře je virtualizován. Je využita platform VirtualBox od Oracle. Podrobně je návrh popsán v kapitolách 4.1 a 4.2. QoS měření Během měření byly dva parametry sítě proměnné, resp. přesně určené nastavením WANemu – šířka pásma a ztrátovost. Protože testování probíhalo v místnosti, ve které se nachází elektronická zařízení a jiné zdroje ruchů, byla metoda ACR daná doporučením ITU-T P.800 upravena viz kapitola 4.3.1 Testovanému subjektu byly testovací nahrávky přehrávány do sluchátek. Dle ITU-T Rec. P.800 doporučuje několik metod hodnocení kvality služby – MOSLQ, MOSLE, MOSLP, ACR a CCR. K praktickému ověření funkčnosti navržené laboratoře byla vybrána modifikována verze ACR (M-ACR). Použité náhravky obsahují tři věty, mezi něž jsou vloženy mezery (volný interval – bez zvuku). Výsledky subjektivních testů jsou shrnuty v tab. 4-1 až tab. 4-10. MOS byl vypočítán pomocí rovnice (3. 1), jehož výsledky shrnuty v tab. 4. 11. Závěr Navrhovaná laboratoř byla úspěšně otestována, návrh splnil očekávání. S využitím navržené laboratoře proběhly subjektivní testy kodeku G.711 na 10 osobách.
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Verification of stable next generation networks via transmission parameters measurement
Gregor, Lukáš ; Čučka, Milan (referee) ; Grenar, David (advisor)
This thesis deals with the measurement of transmission parameters in the new generation access networks NGA. The aim of the thesis is to build and configure a test network and scenarios for the measurement of service quality parameters and then verify the transmission stability. The theoretical part describes general functioning of NGN networks, the requirements of different telecommunications services on quality parameters, methodology and recommendations for measuring transmission parameters in packet networks. The practical part deals with the configuration of scenarios using mainly MPLS technology and methodology of their testing. Measurements were performed according to recommendations IETF RFC 2544, IETF RFC 6349 with the ExacTCP test and ITU-T Y.1564 with the EtherSAM test. For measurements were used measuring instruments of EXFO brand. In conclusion, the measurement results according to the mentioned standards were evaluated and also the advantages of using the measurement according to the given standard in NGA access networks were discussed.
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Diagnostic tool for RTP sessions
Sirotný, Miroslav ; Komosný, Dan (referee) ; Šimek, Milan (advisor)
This work was divided into two parts. In the first part are worked out protocols RTP and RTCP with theory. In this part I show to what these protocols are used. The second part is dedicated to proposal of application for the diagnosis of transmission parameters RTP / RTCP relations. Programs like Tcpdump win, Wireshrak, IP / TV Viewer and the Java programming language with development setting NetBeans 5.5.1. were used while creating the application. In this part we focused mainly at two important parameters like Jitter and Packet Loss.Functionality applications. Finally, we have verifed the function of the application on Multicast Network with running IPTV.
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Measurement of transfer speeds and delays in computer networks
Bárdossy, Adrián ; Kubánková, Anna (referee) ; Jeřábek, Jan (advisor)
Bachelor thesis is interested in measurement of transfer rate and latency in computer networks. In the first part of thesis is defined, which motodics of measurement we know, various RFC and their specifications, also various parameters about measurement in computer networks like bit rate, capacity of channel, latency. In the second part are prepared users interfaces and softwares for applying the measurement of thesd parameters. In the last part is application of these softwares and creating and testing methodic of network measurement.
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Wireless communication link analyzer
Dostálek, Jakub ; Burian, František (referee) ; Jílek, Tomáš (advisor)
The aim of this bachelor thesis is to design and implement a wireless communication analyzer in mobile robotics, using IPv4 protocol and Ethernet interface and to create correctly selected and expressed characteristics from the measured data, according to which the wireless communication channel can be further optimized for the best data transmission. To meet these requirements, a brief search of existing solutions was performed, their applicability was discussed and important parameters of the wireless transmission channel were defined, which will form the given characteristics. Furthermore, the actual design and implementation of a wireless communication link analyzer for previously specified required parameters, verification of its functionality on the transmission link with known parameters and automation of measurement and data evaluation was performed.
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A system for monitoring the quality of connectivity
Vyskočil, Vladimír ; Peterka, Jiří (advisor) ; Děcký, Martin (referee)
The aim of the theses is to design a methodology for centralized monitoring of data traffic in an ISP network that would detect individual connection with connectivity problems, and evaluate these problems. The methodology should at least evaluate packet loss and latency between a centrally located monitoring point and endpoints at user premises. A further goal is to implement this methodology, test it and evaluate the results.
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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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Simulation of communication part of modern industrial networks
Beneš, Pavel ; Blažek, Petr (referee) ; Fujdiak, Radek (advisor)
The thesis is focused on simulating of protocols from standard IEC 61850 in simulation tool OMNeT++. The theoretical part in the thesis deals with description of the field of operating technologies, supervisory control and data acquisition and protocols Tase-2/ICCP, IEC 61850, IEC 60870-5-104, DNP 3 and DLMS/COSEM. Next part deals with parameters influencing connection and description of simulation tools NS2/NS3, OPNET and OMNeT++. In the practical part there is created a network containing protocols from the standard IEC 61850 in the simulation program OMNeT++. Then in the network a end to end delay and packet loss with increasing traffic is measured.
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