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Geolocation of Internet nodes based on communication latency
Horák, Michael ; Balej, Jiří (referee) ; Komosný, Dan (advisor)
This thesis covers the topic of determination of geographical location of a host in internet network while utilizing measurement of the end to end delay and implementation of Constraint-Based Geolocation. Gradually I go through issue of the delay in computer networks and ways how to measure it. Next chapter describes a few ways to geolocate host in internet network with emphasis on the CBG method. Another chapter is dedicated to describing a way to project spherical coordinates to the two dimensional space, which has been used in implementation of geolocation method. Chapter about implementation builds upon the facts given in previous chapters while functions of the program written in the JAVA programing language are being explained. Two similar geolocation methods were implemented. By comparing the results gained by implementation, new method of geolocation is proposed and devised. It combines properities of both previous methods. There are results of the implemented methods and their comparation to the one of the source documents used in creation of this thesis in summary section.
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Quality of service support in unix-like operating system for communication in WiFi networks
Mizera, Josef ; Komosný, Dan (referee) ; Novotný, Vít (advisor)
Diploma thesis is focused on the supporting of Quality of Services in wireless networks, especially in the Linux operation systems. The topic is connected not only with OS, but also with the wireless standard, which supports QoS in wireless networks called IEEE 802.11e. QoS is needed especially for time-consuming data transfers in real time. The theoretical part deals with the theoretical analysis of the issue of the QoS support. There are described parameters, which occurred in quality of services support. This section also deals with the division of services that are used to transmit data across computer networks. It also describes the QoS support in wireless networks according 802.11e, its implementation and methods of accessing a medium with a without possibility of traffic. This part is followed by a description of QoS support in UNIX operating systems. The chapter describes how is the QoS support designed in these operating systems. There are also characterized concrete tools which are used for control the data flow in the operating systems using Linux. At the end the theoretical part deals with different types of queues and methods used in linux OS. In the practical part of the thesis, there are various designed topologies and scenarios to verify the functionality of QoS support in wireless networks using a Unix system. These chapters show the results of different tests at selected transmission data streams that are sensitive to transmission time. There is also verified cooperation of QoS support between devices operating on the network and data link layers. The output of this work is to design a laboratory exercise for the subject Network Architecture. This exercise is focused on familiarization with the QoS support functionality in wireless networks and in Unix-like operating systems. This chapter also describes the devices and programs that are needed to measure this task. The last part of the chapter describes the procedure for the preparation of the measuring station. For this laboratory task, there is an inserted manual in the annex.
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Simulation of data transmission latency between nodes in IP networks
Balej, Jiří ; Molnár, Karol (referee) ; Komosný, Dan (advisor)
This master thesis is focused on the delays incurred in data transmitting over IP networks. The top of the paper is devoted to points, where delay is invoked and causes of the latency. For individual sources of delay are are described the parameters that affect the usual size of latency. The next section describes the types of networks and their typical delay. In the paper are also discussed tools for measuring delay and determining the number of intermediate devices. The thesis contains results of measurements delay time in the real network. For these results are listed conclusions about the delay for one intermediate device. There is also said general ratio of crow-fly distance and calculated distance. The last part deals the simulation of delay in the NS2 program. The results of thesis are scripts that shows the relation of delay and the number of switches, routers, and the length of the path.
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A System for Monitoring Status of Network Links via SNMP
Zubčák, Peter ; Trchalík, Roman (referee) ; Rychlý, Marek (advisor)
The goal of the bachelor thesis is an implementation of the system for monitoring status of network links. System collects information from network nodes, from which calculates metrics and statistics, which are available for users in MIB. The communications with network nodes is proceeded by SNMP protocol. The system is implemented in C++ language as a multiplatform service.
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Measurement of communication latency in IP networks
Bednář, Vít ; Vrba, Kamil (referee) ; Komosný, Dan (advisor)
Semestral thesis is focused on measurement of communication delay in networks. There is described creation of individual kinds of delay during the transfer in networks. Tools for measurement of delay are described and web pages are designed and made too. There is measured delay on choose 27 IP address with help of this page.
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Possibilities of QoS algorithms simulation and optimization
Charvát, Ondřej ; Číka, Petr (referee) ; Krajsa, Ondřej (advisor)
The bachelor's thesis deals with problematics of data transmission control in converged networks which is implemented there to offer telecommunication services in desired quality. Theoretical part of the thesis provides an overview of measurable parameters and lists factors by which they are affected. It discusses different levels of services offered and finally techniques used for it's provisioning as they are implemented in network appliances. In practical part a model of network with QoS implementation is constructed in simulation software Simulink. There are several traffic flows running in the simulated network which has different demands on transfer quality such as telephony or bulky file transfer. There is graphical user interface programmed in Matlab enviroment by which it is possible to alter QoS settings in the model and observe effect on achieved parameters of running data transfers. All simulation results are also displayed on the user interface. User may set all parameters manualy or let the software optimize settings according to prefered criterion, i.e. packet loss. In such way model demonstrates how changes in QoS configuratinon affects quality of services being transferred. The whole model is constructed in a way to be easily reconfigured in case of future use. It is possible for expample to add more traffic or to extend the model to larger network by using predefined blocks.
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Estimate of data strem delay during transit through network device
Dopita, Michal ; Komosný, Dan (referee) ; Verner, Lukáš (advisor)
This thesis is focused on the issue Estimation of delay during the data flow going through network device. There is analyze of network parameters, which influent final delay, detection of delay in data networks and types of delay in the network. The practil part is focused on development of the software, which performs the estimation of delay. At the end there is a summary of the whole thesis and evaluation of measurements.
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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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