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Application of simulation model of access network
Szymeczek, Andrzej ; Sládok, Ondřej (referee) ; Grenar, David (advisor)
The topic of the diploma thesis is " Application of simulation model of access network". The aim of the thesis was to create a part of the access network in which were tested simulations for TCP and UDP traffic. The theoretical part of the thesis deals with general information about the GNS3 program and the possibilities which this program allows. The next part of the thesis describes the Mikrotik RouterOS program, which was used in the topology. The next section describes the types of routing in IP networks, as well as the types of packet delivery. The practical part deals with the creation of test topologies and verification of the performance of the simulation tool. Furthermore, the practical part deals with the programming of a network generator for TCP and UDP traffic in the network. The generator was created by using a Bash script and a combination of the dd and nc commands. At the end, the thesis describes the results of simulations in terms of transmission speed, network throughput, packet size distribution and in the case of TCP also bidirectional delay – RTT.
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Ethernet OAM for access networks diversity control
Varhola, Oliver ; Grenar, David (referee) ; Slavíček, Karel (advisor)
The Bachelor's thesis describes Ethernet access networks and the specifics of the telecommunication Ethernet Service with a focus on Diversity access. Ethernet OAM (Operation, Administration and Management) link layer protocols IEEE 802.1ag and 802.3ah are described, implemented and tested. Suggested use of OAM for verification of Diversity Single Point of Failure (SPOF) trial is conducted by utilizing Link Trace Message / Link Trace Response (LTM/LTR). Simulation using GNS3 emulator is performed in order to capture Link Layer (L2) traceroute to neighboring MIPs and MEPs (Maintenance Intermediate Points and Maintenance End Points). The resulting traceroute path containing MAC addresses of the ports through which the frame was sent is recorded, analyzed and compared with a sibling diverse circuit. If MAC addresses are equal or from a close range it indicates that the circuits may pass through the same device and thus a potential SPOF is detected.
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Design of optical fiber temperature sensor for detection of defense perimeter
Zámečník, Ondřej ; Grenar, David (referee) ; Filka, Miloslav (advisor)
This diploma thesis deals with the issue of measuring the ambient temperature using a~single-mode optical fiber used as a temperature sensor. The thesis describes the basic knowledge about polarized light, its propagation in optical fiber and describes special fibers that preserve polarization. It also deals with the representation of polarization states on a Poincaré sphere and the use of Stokes and Jones vectors. In the practical part, several selected methods of optical signal supply to the temperature sensor are measured. Subsequently, the suitability of the given methods is evaluated from the measured results and the courses are compared with the records measured from real routes. This thesis aims to select a suitable connection of a temperature sensor for a long route of optical fiber and verify its functionality.
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Birefringence Influence on Polarization Changes and Frequency on Optical Fiber Sensors
Panascí, Marco ; Grenar, David (referee) ; Filka, Miloslav (advisor)
This bachelor thesis deals with birefringence influence on polarization changes and frequency on optical fiber sensors. The objective of the thesis is to design and implement a set of measurements that analyze these effects. The theoretical part deals with analyzing the polarization-maintaning fiber, the polarization of the light, and the sensory optical fibers, with some research. The practical part deals with design of the workplace, control measurement and sensor response at different temperatures. After the practical part there is a discussion over the measured values. It was found that this sensory optical fiber responds to a change in the ambient temperature of the optical fiber. The main result is that the wavelength varies with temperature.
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Optical Fiber Output Power Temperature Sensor Measuring Optimization
Koláčková, Aneta ; Grenar, David (referee) ; Filka, Miloslav (advisor)
This bachelor thesis deals with the issue of measuring optic power on the output of single mode fiber, used like temperature sensor, using birefringent. Thesis describes the basic knowledge about measuring power, standards and function of optical power meters. It also deals with polarization and representation polarization states using the Poincare sphere. In the practical portion is measured optic power on the output of the temperature sensor with a photodiod and after that is verifed by a polarimeter. The aim of this thesis is miniaturization of ending device for measuring intensity of light, that means replacing expensive and large polarimeter by cheap and small photodiod.
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Multi-channel polarization optical fiber sensors in wave multiplex technique
Švehlík, Martin ; Grenar, David (referee) ; Filka, Miloslav (advisor)
The diploma thesis deals with the optical fiber sensor system assembly and its possibilities using 100 GHz wavelength multiplexing (DWDM), when using standard single-mode communication fibers. In the introduction, the necessary theoretical knowledge is discussed. The aim of the work is to design a temperature field violation sensor with remote excitation and detection. The practical part of the thesis contains the design and assembly of the measuring workplace. Also, the results of each measurement are presented, and at the end, they are compared and assessed.
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Monitoring of services within active network elements by Mikrotik
Kamenář, Filip ; Slavíček, Karel (referee) ; Grenar, David (advisor)
This bachelor thesis deals with the monitoring of the VPN services on the networking elements Mikrotik. The theoretical part includes the description of RouterOS system, management options and networking devices used. The thesis consists of the description of the VPN services and analysis of PPTP, SSTP, L2TP and OpenVPN protocols, which are implemented in the practical part of this work. The theory also contains the description of monitoring devices included in the RouterOS system. In comparison, external tools are enlisted. Chosen monitoring tools are therefore implemented in the practical part of the thesis and in the monitoring script. The practical part of the bachelor thesis is focused on the establishment of VPN tunnels and its parameter measurement. The VPN clients are to be found in the Czech Republic, Ukraine and Egypt, which establishes the real conditions for network monitoring status. The final part of the work deals with the script, which is created for the automatic-monitoring of VPN service in the accessible network and sends the gathered data to the operators. The aim of the thesis is to illustrate the usage of integrated monitoring tools in the RouterOS system in the network built on the Mikrotik elements. The chosen monitoring service was the service VPN, which is being used for remote access to the local networks from distant part of the world by the corporations but also individuals. Individual monitored parameters are enlisted and compared depending on client geographic location.
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Utilization of open source tools for access network monitoring
Gmitter, Jakub ; Sládok, Ondřej (referee) ; Grenar, David (advisor)
The bachelor thesis deals with the issue of access network monitoring, which is necessary to ensure the stability of access networks. It contains a comparison of suitable monitoring tools for their selection. The work is focused on creating scripts in the Bash language, which analyze data on the access network and implement outputs from selected monitoring tools. In this work were analyzed the transmitted packets and the achieved transmission speeds during monitoring. The final output of this work are databases created in MySQL, which contains data about the analyzed parameters and visualization of data analysis using the Grafana program. Graphs of the transmission speeds of monitoring and basic transmission statistics were created on panels during visualization.
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Laboratory scenarios for comparison of protocols allowing transmission of web pages
Moučka, Martin ; Grenar, David (referee) ; Jeřábek, Jan (advisor)
This diploma thesis focuses on theoretical and practical comparison of webpage transport protocols such as HTTP/HTTPS (Hypertext Transfer Protocol) v1.1, SPDY, HTTP/2 and QUIC using UDP (User Datagram Protocol), TCP (Transmission Control Protocol) and SCTP (Stream Control Transmission Protocol) as transport protocols. This work also contains design and manual for practical laboratory tasks on which can students verify theoretical assumptions. These tasks compares protocols in different conditions such as packet loss, latency and jitter.
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Application for geolocation databases
Farkaš, František ; Grenar, David (referee) ; Komosný, Dan (advisor)
The topic of this thesis is testing and analysis of geolocation databases and comparison between commercial databases and noncommercial ones. Practical part is dedicated to implementation of application which is testing the databases and gathers the output data for analysis. First chapter of the thesis describes geolocation, use of geolocation and methods of getting geolocation data. Second chapter deals with implementation details of application and technologies used for implementation. The last chapter is dedicated to analysis and comparison of tested databases.
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