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Bonding, the method for increasing DSL data rate
Kratochvil, Tomáš ; Benešl, Lukáš (referee) ; Šilhavý, Pavel (advisor)
This bachelor thesis focuses on characteristics of DSL bonding technology. The basic information about DSL technologies is described at the start of theoretical part of thesis. VDSL2 technology is described more thorougfully in comparision with other DSL technologies, because in this thesis DSL bonding is applied on VDSL2 technology. Next chapter of theoretical part of thesis describes principe of DSL bonding technology. Final chapters of theoretical part of thesis describes recommendations for testing of network characteristics. Specifically these network testing recommendations are described: RFC 2544, RFC 6349 and Y 1564. The results of performed tests are presented in practical part of thesis. Tested DSL technologies are compared based on results of performed tests at the end of practical part of thesis.
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BCH codes
Frolka, Jakub ; Šilhavý, Pavel (referee) ; Šedý, Jakub (advisor)
The work deals with data security using BCH codes. In the work are described BCH codes in binary and non-binary form, and their most important subclass RS codes. Furthermore, this work describes the method of decoding Peterson-Gorenstein-Zierl, Berlekamp- Massey and Euclidean algorithm. For the presentation of encoding and decoding process, the application was created in Matlab, which has two parts – Learning BCH codes and Simulation of BCH codes. Using the generated application performance of BCH codes was compared at the last part of the work.
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Proprietary VoIP protocols of PBX manufacturers
Bělík, David ; Daněček, Vít (referee) ; Šilhavý, Pavel (advisor)
This thesis focuses on the analysis of proprietary Voice over IP protocols. The first part describes the principles and VoIP technology types. The next section describes proprietary protocols Panasonic IP-PT from Panasonic Corporation and Siemens CorNet-IP from Siemens Corporation. Protocols which are being used in these systems are listed here. Further there is being described the process of registration of terminals to central province. Subsequently calling process and particular terminal functions including packet analysis are being decoded in detail. In conclusion H.323 and MGCP protocols are being compared.
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LDPC codes
Hrouza, Ondřej ; Šedý, Jakub (referee) ; Šilhavý, Pavel (advisor)
The aim of this thesis are problematics about LDPC codes. There are described metods to create parity check matrix, where are important structured metods using finite geometry: Euclidean geometry and projectice geometry. Next area in this thesis is decoding LDPC codes. There are presented four metods: Hard-Decision algorithm, Bit-Flipping algorithm, The Sum-Product algorithm and Log Likelihood algorithm, where is mainly focused on iterative decoding methods. Practical output of this work is program LDPC codes created in environment Matlab. The program is divided to two parts -- Practise LDPC codes and Simulation LDPC codes. The result reached by program Simulation LDPC codes is used to create a comparison of creating and decoding methods LDPC codes. For comparison of decoding methods LDPC codes were used BER characteristics and time dependence each method on various parameters LDPC code (number of iteration or size of parity matrix).
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Securing IP PBX against attacks and resistance testing
Kakvic, Martin ; Šedý, Jakub (referee) ; Šilhavý, Pavel (advisor)
This diploma thesis focuses on attacks on PBX Asterisk, FreeSWITCH and Yate in LTS versions. In this work was carried out two types of attacks, including an attack DoS and the attack Teardown. These attacks were carried out using two different protocols, SIP and IAX. During the denial of service attack was monitored CPU usage and detected if its possible to establish call and whether if call can be processed. The Security of PBX was build on two levels. As a first level of security there was used linux based firewall netfilter. The second level of security was ensured with protocols TLS and SRTP.
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DLMS concentrator simulator
Buš, Ondřej ; Šilhavý, Pavel (referee) ; Lieskovan, Tomáš (advisor)
This work is focused on a field of smart metering and data concentrators. The first part of this paper describes the DLMS/COSEM specification. The first section contains DLMS protocol specification, the process of communication between devices and services that allows data communication. COSEM classes and objects can be found in the second section. These objects are used to access a specific data stored inside smart meters. Lastly, there is an section that is focused on OBIS objects which are used for addressing. In the second part, the concentrator's basic functionalities are described. These functionalities include device management and configuration file storage. The last part then focuses on a web server. The web server allows a user to manage the concentrator by adding, editing and removing connected smart meters.
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Visualization of forward error correction securing by block and cyclical codes
Fančal, Petr ; Číž, Radim (referee) ; Šilhavý, Pavel (advisor)
This bachelor thesis provides an introduction to the principles of forward error correction securing by linear block and cyclical systematic codes and its visualization by educational application. First part of the thesis contains comprehensive theoretical base of principles of forward error correction securing and capability of linear block and cyclical systematic codes. Second part describes the educational application, realized in graphical user interface GUI of MATLAB. This application step by step visualizes parts of procedures of securing, error detection and correction. Its main benefit is its usability as illustrative teaching aid.
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Performance limits, reliability and security of open source PBX
Bednár, Jakub ; Šedý, Jakub (referee) ; Šilhavý, Pavel (advisor)
The aim of this thesis is to install and to configure three Open source PBXes Asterisk, Freeswitch and YATE. Furthermore, the aim is to realize the performance test and stability tests on three different HW configurations with the tester Spirent Abacus 5000. The scripts in bash were created to monitor PBX performance. Another part of the study is to analyze and to compare PBX security and to compare the Open Source PBX with a proprietary PBX Alcatel-Lucent OXE.
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SIP implementations in Asterisk open source PBX
Bednář, Vít ; Krajsa, Ondřej (referee) ; Šilhavý, Pavel (advisor)
The thesis compares native SIP stack with PJSIP stack in the open source telephone private branch exchange (PBX) Asterisk. First, there are described both SIP protocol and Asterisk application. Subsequently, the architecture, new function support and the stacks setting possibilities are explored. For different exchange scenarios several commented configuration files are presented. The stacks are tested using Spirent TestCenter C1 software thereafter. In conclusion, selected properties are assessed and new PJSIP stack benefits are summarized. In addition, the laboratory assignment is attached.
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Kamailio and OpenSIPs open source PBX
Janeček, Václav ; Krkoš, Radko (referee) ; Šilhavý, Pavel (advisor)
Open source PBX Kamailio and OpenSIPS diploma thesis covers familiarization with appointed SIP exchanges and with their power comparing. A detailed installation instructions on the operating system Ubuntu is the aim of this work too. The work includes the historical development of telephone exchanges with a focus on the latest generation. The following is SIP protocol basic description and components that can be composed SIP exchanges. Another part is devoted to the development of exchanges Kamailio and OpenSIPS. The thesis contain the archutecture and configuration file description. The practical part of the thesis deals with high-capacity switches, and comparing it in terms of memory and computational demands. Selected measurements are compared with the Asterisk PBX.
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