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Implementation of Quality of Service into Wireless Networks
Kaman, Štěpán ; Růčka, Lukáš (referee) ; Škorpil, Vladislav (advisor)
Wireless networks are currently the frequent access connection to the local network or the Internet. Until 2005 there was no support in the 802.11 standard priority data and the use of multimedia services in these networks is problematic. Thesis deals with the standard IEEE 802.11 standard and quality of service support including IEEE 802.11e. They discussed methods of access to transmission medium, differences in the MAC sublayer, the reader issues in the transmission of priority data and the requirements for these data. In Opnet Modeler was created wireless network with access points and stations on which they are carried out simulations at different strain of transmitted data. It studied the difference in the use of DCF and EDCF method, used in the network with QoS support. In particular, it examined the behavior of priority voice and video data in both networks. The focus is on key parameters such as throughput, dropping data, packet loss, delay, jitter and the size of broadcasting front. The measured data are analyzed, and differences in the network without the support and promoting the quality of services are compared and evaluated. Part of this work is the role of laboratory in the Opnet Modeler.
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Integrated telecommunication environment
Tomeček, Jan ; Škorpil, Vladislav (referee) ; Polívka, Michal (advisor)
The thesis described the proposal for a wireless network problems. There are recorded and compared the characteristics of different wireless technologies. The possibility of voice communication securing is outlined and solutions implemented in the form of ZRTP protocol. The requirements for quality of service are discussed and the solutions to this issue are proposed. Other chapters are devoted to the actual design of specific equipment, including antennas and advance resource. The whole network is practically implemented in the mountainous countryside of eastern Wallachia. In conclusion, this work is network mate in terms of QoS (quality of service) and tested in terms of prioritization of voice communication.
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Voice-over-IP principle and security problems
Bořuta, Petr ; Hošek, Jiří (referee) ; Vyoral, Josef (advisor)
This master’s thesis deals with security properties of protocols used for VoIP systems. In the first part, there is a description of most commonly used protocols and structure of VoIP systems. This part also discuss signaling and transport protocols. The second part of this paper describes techniques of ensuring quality of services. The next part presents SIP messages and communication. Last part of this paper overviews security risks of VoIP protocol. Practical part of this thesis describes creation of a testing VoIP network, on which several attacks has been made, fallowed by securing of mentioned VoIP network. Result of this thesis is evaluation of security risks connected to VoIP communication.
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Methods for Quality of Service measurement in Wi-Fi networks
Bachan, Jiří ; Kolka, Zdeněk (referee) ; Prokopec, Jan (advisor)
This work deals with the wireless Wi-Fi networks, that used unlicenced ISM frequency band 2,4 GHz. These wireless networks are very extended in these days and used mainly for the Internet connection. With the multimedia data transfers expanding it’s necessary to ensure the specific quality of service QoS in wireless networks mainly for applications, which are sensitive to delay or packets lost. The main aim of this work is to describe Wi-Fi networks based on IEEE 802.11b/g/n standards, description of QoS techniques according to IEEE 802.11e standard and description of parameters describing QoS for the VoIP services. The practical part is divided on a two parts. The problems of measuring the radio link quality and the creation of simple program for quality of wireless connection analysis are solved in the first part. The second part incluledes measuring of the lost packets number in Wi-Fi network with the commercial application AirMagnet Laptop Wireless LAN Analyzer and measuring of the signal noise influence with the help of spectrum analyzer and vector signal generator.
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Quality of services support in the end applications
Zelinka, Jiří ; Novotný, Vít (referee) ; Hošek, Jiří (advisor)
The topic of this diploma thesis has been chosen for a discussion and implementation of quality of service on the application and link layer of the OSI model. At the beginning of this thesis the general parameters and basic technologies of the OSI model network layer has been explained. This part was chosen as a resource for explanation of the basic parameters in the quality of services. Basic part is followed by the introduction to the Ethernet technology, which became as a ground for the real model in this diploma thesis. As a part of this section has been written a block which contains a analysis of quality of services in the Ethernet, which means the implementation of IEEE 802.1Q/p. This analysis is followed by structured descrition of the controlling and functionality of quality of services parameters on the link layer with the system tool in the Windows XP, description of Win XP link layer drivers and its modification with system tool tcmon. The end of the theoretical part is represented by introduction to the implementation of quality of service in the wireless networks especially the 802.11e standard. At the beginning of the practical part is specified the description of the topology design which is dedicated to the quality of services implementation. This section is developed to well-founded analysis of applications which were used during topology creating. The last segment of this thesis is dedicated to evolving the practical informations which were obtained during the measurement.
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Development of IP Multimedia Subsystem architecture
Hladíková, Vladimíra ; Číka, Petr (referee) ; Novotný, Vít (advisor)
Bachelor thesis topic is focused on convergence of networks and services in the environment of mobile networks with implementation of Internet Protocol Multimedia Subsystem (IMS). The first part is, devoted to reasons of design of new system, such as IMS (Internet Protocol Multimedia Subsystem) and which possibilities this architecture brings to users. I mentioned institutions and organizations, which are involved in the development of this system. In this chapter is shortly defined history of single standardised parts. In the next part is defined the IMS architecture its main part and functions. I defined which services of this system are possible to offer. To guarantee the high-quality transfer in the sites based on IP protocol is very important to guarantee quality of QoS (Quality of Service) services. So I take the aim to that in one of the next chapters. I mentioned quality assurance principles. The main factor that influences the quality of the transfer is which type of data is being transferred in IP network. The next charter is devoted authentication and authorisation in IMS network. I described the integration with Diameter protocol. The main part is devoted to VoIP (Voice over IP), the transfer of voice in IP networks. I defined the main idea of transfer of voice in IP networks. Codecs are very important for the voice transfer in IP networks, so I give a conspectus here. The next chapter gives attention to used protocols. The system could not work without them. It goes around SDP (Session Description Protocol), protocols for real-time data transfer RTP (Real-time Transport Protocol), RTCP (RTP Control Protocol), RTSP (Real-Time Streaming Protocol) - and the most important signalling protocol SIP (Session Initiation Protocol) and its integration with IMS. Finally I rated possibilities of IMS in mobile communication network and their use for VoIP. Among others I take into consideration also economical influences over the expansion of equipment supporting services with implementation IMS for general public.
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Possibilities of connecting the Asterisk softswitch to the 4th generation PBX
Halamík, Zdeněk ; Krajsa, Ondřej (referee) ; Šilhavý, Pavel (advisor)
This master’s thesis dissertate the possibilities of the linkage between Asterisk softswitch and the 4th generation private branch exchange. This should create a new generation’s network, so-called NGN, by the convergence of existing telecommunication networks with an IP computer network. This master’s thesis is divided into several chapters. In introduction is described the evolution of the private branch exchanges as well as the principles of the voice digitizing, codecs and signaling commonly used in both TDM and VoIP networks. The main aim of this project is the configuration of Asterisk software exchange for connection with PBX Alcatel 4400 as well as public phone network PSTN. Another goal of this master’s thesis was the configuration of Alcatel PBX and diagnostics of CCS and CAS signaling on E1 interface. In conclusion there are summarized advantages of NGN networks and their utilization in the future.
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Converged solution of speech services
Mácha, Tomáš ; Kovář, Petr (referee) ; Novotný, Vít (advisor)
Development in VoIP technology is connected with the rapid growth of quality and data rate of the Internet connection. The application of the VoIP technology has become one of the key areas in telecommunication and networking. The main task of this thesis was to explore the questions of IP telephony and voice transmission over data networks according to H.323, SIP and Cisco architectures. Next focus was on designing and implementing experimental workplaces of mentioned architectures and their converged solutions. The purpose of the first chapter is to introduce the theory background of architectures required for implementation of real-time services in data networks and their comparison. The key objectives of the second and third part are to design and implement experimental workplaces containing signaling and proxy servers and hardware or software IP phones of several architectures. Illustration examples of different network topologies are included to demonstrate designed and realized VoIP solutions. Several tests of established communication are done using a packet analyzer. These tests examine duplex data transmission over IP. This article also contains two laboratory exercises designed according to gained practical experiences. The laboratory exercises provide an overview of theory and clearly indicate the possibilities of IP telephony.
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Communication systems based on IP telephony
Zimek, Josef ; Kapoun, Vladimír (referee) ; Herman, Ivo (advisor)
My master’s thesis is focused on designing and creating communication network, which provides communication between two independent networks through encrypted tunnel. My solution is based on routers formed by older personal computers with FreeBSD like a operating system. Between routers is created static encrypted tunnel by using IPSec protocol. Voice services provides packet oriented exchange Asterisk with support of signaling protocol SIP. This solution can be used eg. for connecting remote branch to headquarters of company and then can branch utilize shrared resources. To headquarters can connect also remote workers from their home. In this case are used SSL certificates to authentication of user. This scenario is very required today.
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Management and configuration of Asterisk VoIP exchange
Binder, Tomáš ; Krajsa, Ondřej (referee) ; Číka, Petr (advisor)
This diploma dissertation is dealing with the VoIP software exchange Asterisk. In the dissertation there are described its abilities and possible ways of its configuration. Special attention is given to the signalling protocol SIP, which is described in one of the chapters. Within this dissertation a dial plan, which demonstrates the technique of dial plan creating, was created. Within the boundaries of the dialplan following services could be found: a voicemail, conference, Interactive Voice Response and call queues. Configuration files, with the help of which the exchange is configurated, are described in my dissertation as well. Finally, three laboratory assignments for purposes of the subject Multimedia Services are mentioned. Their main aim is to familiarise students with the creation of SIP accounts in the exchange, their mutual connections, defining the Interactive Voice Response and forming a new call centre.
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