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.

This thesis consists of theoretical and practical parts. The theoretical part contains an analysis of the problems of wireless networkssolutions individual standards and methodologies to ensure quality of service. In the practical part using the OPNET Modeler, a number of different simulation models and their evaluation. It is a model of individual standards, support mobility and interference effects on quality of service.

This thesis describes the design and implementation of system for effective detection of network anomaly using DNS data. Effective detection is accomplished by combination and cooperation of detectors and detection techniques. Flow data in NetFlow and IPFIX formats are used as input for detection. Also packets in pcap format can be used. Main focus is put on detection of DNS tunneling. Thesis also describes Domain Name System (DNS) and anomalies associated with DNS.

This thesis deals with the identification of useful data in lawful interception. First part summarizes the standards related to computer networks and lawful intercepts. Next part of the project focuses mainly on the HTTP application protocol, which is described in version 1.1. The work also specifies the classes into which the data traffic can be divided according to the importance to law enforcement agency. It introduces several methods of distribution of data streams into the proposed classes. Finally, the implementation of this methods has been tested for usability in network lines used today.

This thesis focuses on algorithms for longest prefix match (LPM), which is the key operation in packet classification and routing in TCP/IP networks. A space for analysis of commonly used algorithms with emphasis on their speed and memory efficiency is dedicated along with necessary theory. Focus is then oriented on IPv6 networks, their typical prefix sets and comparison of suitable algorithms. Afterwards, the optimization for selected algorithm is suggested and implemented in programming language Python.

This thesis focuses on methods for fast recognition of application protocols. Fast recognition is recognition with minimal delay from the time of capturing the first data packet sent  from the source node. This thesis describes possible techniques and methods for recognition of application protocols and basic information and description of reference system for lawful interception in computer networks. Furthermore, the thesis describes analysis, design and implementation phase of a tool for fast recognition of application protocols. The conclusion of this thesis describes the results of tests performed by the tool and shows its limitations and possible extensions.

Software testing is a process in which we try to check functionality and quality of tested software product. In this thesis we will discuss testing of Linux kernel in order to check up its functionality and performance of its network related part. We use our own metrics developed on standards, which describes testing of network active devices.

The speed of computer network is increasing. One of the basic tasks which has to be solved by the network devices is longest prefix match. Many algorithms are able to solve this task but it's necessary to solve it very fast because of increasing transfer speed and the routing standard IPv6. This standard has longer addresses and it's necessary to search prefixes in much bigger sets. The thesis describes present algorithms that solve the problem. These are confronted with new algorithm HashTreeBitmap which is also described in the work. On the tests is documented that this algorithm is able to cope with high demands which are placed on it.

This work deals with construction of an embedded system with remote access, whitch controls computers in the same network in order to reduce their energy consumption. For this purpose is used the WakeOnLAN technique. The device also uses two power components called SSR and  these are used for switching AC power to them attached appliances. The work discusses the TCP/IP architecture, system design and finally the firmware implementation.

This master thesis deals with the design and implementation of an application for analyzing Voice over IP quality using NetFlow. In the beginning, there is summarized basic information about VoIP technology and NetFlow - its principles, the most used protocols, factors that have influence on call quality and call quality rating methods. Later there is presented proposal of application and then described its implementation. The created application was tested on samples, which simulate calls in network with delays and packet-loss. Within testing was made the comparison with commercial application and the results are discussed.