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Application for monitoring and controlling the security of large LAN and WAN computer networks
Maloušek, Zdeněk ; Polívka, Michal (referee) ; Novotný, Vít (advisor)
Computer networks are used in much wider extent than 20 years ago. People use the computer mainly for communication, entertainment and data storage. Information is often stored only in electronic devices and that is why the security of the data is so important. The objective of my thesis is to describe network security problems and their solutions. First chapter deals with the network security, security checks and attacks. It describes procedures used in practise. First part deals with traffic scanning and filtering at various layers of the TCP/IP model. Second part presents the types of proxy and its pros and cons. Network Address Translation (NAT) is a favourite technique of managing IP addresses of inside and outside network which helps to improve the security and lower the costs paid for IP addresses. NAT description, IPSec, VPN and basic attacks are described in this section. The second chapter of the thesis presents set of Perl scripts for network security checking. The purpose of the project is not to check the whole network security. It is designed for contemporary needs of IBM Global Services Delivery Centrum Brno. The first script checks running applications on target object. The aim is to detect services that are not necessary to run or that are not updated. The second one checks the security of the Cisco device configuration. There is a list of rules that has to be kept. The third script inspects the Nokia firewall configuration which is on the border of IBM network. If some of the rule is broken, it shows the command that has to be proceeded at the particular device. The output of the first and the second script is an HTML file. The third script uses the command line for the final report. The last part of this chapter gives advice to configure Cisco devices. It is a list of security recommendations that can be used by configuring e.g. routers. The appendix presents two laboratory exercises. The aim is to give students an opportunity to learn something about programs and technologies which are used in practise by IT experts to check the weaknesses of their networks.
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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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Architecture of channels in UMTS networks
Souček, David ; Vyoral, Josef (referee) ; Novotný, Vít (advisor)
Mobile networks and their services are one of the most importantly developing domains of telecommunication these days. The mobility of subscribers and services is the funda-mental need for dynamic development of not only the economics, but also of other fields of human performance. The charge for the mobility and integration of various kinds of services in mobile networks is an extensively complicated architecture and a protocol equipment. The important aspect of mobile networks is the efektivity of utilization of radio sources, which are scarce and form so called narrow neck of the communication chain between the mobile terminal and the network terminal. That is the reason why the perfection of mobile technologies is closely related to the improvement of efficiency of the usage of radio sources, which is reflexed in the UMTS network by an extensively complicated layer architecture of communication channels, that is formed by three layers as distinct from the GSM/GPRS network, where the architecture of channels was in two layers.
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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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Use of reliable multicast for feedback transmission in IPTV
Sobotka, David ; Novotný, Vít (referee) ; Komosný, Dan (advisor)
This Diploma thesis is focused on a part of network communication in the system of IPTV using the protocol to provide transmission of real-time multimedia RTP, specifically using the control protocol RTCP to carry voting results. The thesis further shows variants and ways of using reliable multicast and specific multicast (SSM). The main practical goal of this thesis is the program for the simulation of carrying voting results that I have created in the C++ programming language for MS Windows platform. The result is the client program receiving an inquiry from the server and reacting by application packets of the RTCP protocol. On the other side is the server program that picks up the packets and processes them. The programs run in the console mode, thus they have no graphical user interface. A user in the server program can create any inquiry and consequently send it to the client. Furthermore, the server can possibly view the current results of voting. In the client program a user can vote and possibly send another vote that will simulate other clients.
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Mechanisms of QoS assurance in fixed, wireless and mobile data networks
Václavek, Radovan ; Novotný, Vít (referee) ; Molnár, Karol (advisor)
This bachelor´s thesis deals with mapping technologies and base parameters used to guarantee the quality of systems in the local area networks, including wireless and mobile ones. I have focused mainly on requests and classifications, which are typical for the types of networks on link layer. In Ethernet I focused on the gradual trends in the fore mentioned technologies and IEEE 802.1Q and connected IEEE 802.1p standards included. The next part describes the quality of systems in wireless nets in different types of environments and again uses given standards for quality of systems guarantee in 802.11e and connected 802.11a/b/g standards. The next part focuses on the latest generations of mobile nets, looking at the types and trends of the latest technologies. Here I draw from standard project 3GPP, which describes the problems with these technological developments. The next part focuses on WiMAX technologies. In the penultimate paragraph, the constituent network technologies are compared from the view of securing QoS and I propound possible ways of securing coversion of constituent technologies. The conclusion summarises all the technologies I have mentioned and the future trends including possible problems and challenges with these latest technologies.
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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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Methods of multiple access for terrestrial radio networks
Žák, Josef ; Novotný, Vít (referee) ; Havelka, Dušan (advisor)
The content of this work is focused on the methods of multiple access for terrestrial radio network. These methods are exploited by the systems second and third generation of mobile networks. Specification the basic characteristics these methods is responsible part for inquest the correspondent specificities. Reason is that, that the wireless mobile communication it is possible split by three generation. First is NMT, with analog frequency modulation, which dont make use already, because has considerable disavantages . Analysis second generation mobile systems GSM leads to determination to many advanta- ges hereof system, who be based on methods FDMA, TDMA, CDMA. Description these methods is specialized on their spreading properties. Third generation of mobile systems UMTS is characterized wideband technology WCDMA, making use two duplex methods (FDD, TDD). Both methods provide higher efficiency of recovery frequency spectrum . All the theoretical approaches are examined in the last part of this work.it´s then possible after complete analysis these methods, make a design and a realization. In this event was used the computer programme Matlab–Simulink for simula- tion of duplex method WCDMA-FDD. Evaluation of this technology provides confrontation with second generation GSM .
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Data acquisition from a great number of computers using hierarchical summarization
Jelínek, Mojmír ; Novotný, Vít (referee) ; Komosný, Dan (advisor)
This paper deals with IPTV (Internet Protocol Television) transmission of feedback and is showing options and ways of construction, problems and optimalization of signalization protocol. In the beginning are described IPTV and technology terms that this technology uses. Here can be found information about classical TV (Television) transmitting and comparing with IPTV technology, the advantages and disadvantaged of IPTV and answers why this solution has future. Next parts are about history of IPTV and real use over ADSL (Asymmetric Digital Subscriber Line) in present. Here are explained all the necessary units like Head-End, feedback target, root feedback target, ADSL, DSLAM (Digital Subscriber Line Access Multiplexer) and methods of data stream transmission. Also here are described the techniques of video stream compression (MPEG-2 and MPEG-4) and all options of data transmission as broadcast, unicast and multicast. Important part is about transmission speed and needs. The realization also contains applications, written in the C++ language, for transmitting and receiving packets by UDP (User Datagram Protocol) protocol. The task of these applications is to load the main server, where the measurement of packet loss and CPU (Central Processing Unit) load takes place. The result is a table of measured values for specified packet sizes and for specified time intervals between them. The meaning of this measuring is to find the maximal number of computer nodes, which the feedback target is able to proceed. Last part is about realization of 2 applications in JAVA language, which get the information about end-nodes. Both algorithms are using 2 threads to increase speed of getting the information. The client has few random generators within one thread, which will be later replaced by special algorithms for getting real values.
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