The topic of this work is verification of support WebRTC communication through selected Open Source PBX. This work examine demands for WebRTC communications and describes configuration of branch centers for this type of communication. In the theoretical part is reader acquainted with the term WebRTC and with protocols related to this kind of communications. The purpose of this part of the work is to bring the reader closer look to the principles of functioning to ensuring support for this kind of communications. This is also connected with Description of basic interfaces of WebRTC applications. Further the reader finds the configuration of the selected Open Source PBX so that they can make audio-video call between WebRTC clients. This section is divided into three subchapters, each of it deals with the same problems for one of the aforementioned PBX. At the end of each chapter where the PBX PBX is configured step-by-step, test calls are made. These calls are captured by the Wireshark packet analyzer and serve as a demonstration of the WebRTC configuration functionality. At the end of this section, PBXs are compared against each other about WebRTC support. Practical part is dealing with laboratory task for students which are studying subject telecommunication and information systems. In the task students will be configuring WebRTC for PBX Asterisk. The task contains brief description of WebRTC and comments for all steps for configuration. All steps and facts are demonstrated by exemplary configuration files.

This thesis describes architecture of IP telephony networks based on signaling protocol SIP and transport protocol RTP. Also tools used for analyzing VoIP traffic are described. Main objective is to design and implement a system for the detection of calls and extraction of voice payloads from  the captured packets. The system first recognizes the signaling messages of SIP protocol. These messages are analyzed afterwards. Output statistics are generated based on gathered data. Voice data will be stored in form, which is suitable for further processing.

The main focus of Master’s thesis is modern methods for user authentication. In the first part are briefly described currently used protocols and pointed out thein advantages and disadvantages. The theoretical introduction analyzes the principles of zero-knowledge authentication, password-based protocols and describes the concept of a new generation hash function. The practical part describes the specific implementation of authentication protocols - Ohta-Okamoto protocol as a representative of the zero knowledge protocols and SRP (Secure Remote Password), which represents password-based protocols. In both cases, the installation procedure is described following the analysis of their implementation (at the source code level) and then compared with the transmitted data captured by Wireshark. The SRP protocol is verified by AVISPA tool. There is summary of both protocols security analysis in the conclusion.

The work deals with the use of software-defined radio as a probe for monitoring the operation of wireless communication according to the IEEE 802.11a/g standard. In the theoretical introduction, the concept of software-defined radio as a hardware device with software programmable circuits enabling the transmission or reception of signals in theoretically any frequency band is introduced. The introduction also contains adescription of selected devices and the IEEE 802.11 protocol with its most used additionsand modulations. In the first part of the practical part of the work, wireless communication is capturedusing a wireless network card in monitoring mode. The intercepted communication was decrypted and this decrypted traffic was compared with the data captured by the probe within the network. These results then served as acomparative basis for software-defined radio capturing. The focus of this work is to verify the capabilities of software-defined radio and its use for sniffing wireless communicationin the frequency band 2.4 GHz and 5 GHz. The attempt to use a software-defined radio here results from the scalability and adaptability that a wireless card cannot offer due to fixed hardware parameters. LimeSDR mini, LimeSDR and bladeRF 2.0 devices were used for capture. First, the configuration of the operating system, the installation of drivers and programs for control and work with selected devices are described. After verifying the functionality of the software-defined radio, a model of a signal decoder with the parameters of the IEEE 802.11g standard captured from the radio spectrum was put into operation. Finally, the data streams captured by the software-defined radio and the wireless network card were compared side by side. The results showed that the software-defined radio in the used configuration captures only a part of the total volume of transmitted frames.

Med denna uppsats vill jag undersöka om Virtual Routing and Forwarding (VRF) kan förhindra spridningen av datamasken Blaster mellan två kunders nätverk. Ämnet VRF valdes för att det finns ett personligt intresse och för att det är en viktig säkerhetsfunktion i ett större nätverk.För att undersöka detta genomförde jag två tester, en utan VRF och en med VRF. Datamasken aktiverades i båda testerna och spridningen analyserades med programvaran Wireshark.Testen visade att VRF segmenterar nätverken på ett sådant sätt att Blaster inte kan sprida sig mellan två nätverk som är segmenterade med VRF.

This work is about Hierarchical agregation and it describes its parts in the rst part of this work. Next is described its parts, main features and properties in this rst part. Document describes the possibilities of realization. Second part describes an analysis of the stability problem. Realizes the detection of failures of the Feedback target stations by the implemented protocol. The protocol is programaticly realized in JAVA language and tested in the real enviroment. In this document it is described an function of bandwidth on the speed of failure detection. The issues of detection of failure on the feedback target manager machine are discussed in this document.

The aim of this thesis is to show how to design and implement an application for network traces analysis using Apache Spark distributed system. Implementation can be divided into three parts - loading data from a distributed HDFS storage, supported network protocols analysis and distributed data processing. As a data visualization tool is used web-based notebook Apache Zeppelin. The resulting application is able to analyze individual packets as well as the entire flows. It supports JSON and pcap as input data formats. The goal of the application is to allow Big Data processing. The greatest impact on its performance has the input data format and allocation of the available cores.

The aim of this diploma thesis is to create two exercises for students. The first exercise is concerned with comparison of transport protocols TCP and UDP. The second exercise is concerned with comparison of routing protocols OSPF and RIP. The first part describes used simulation environment. The next part describes the operating system used in routers. The following part describes the procedure of installing virtual machines. The next part consists of theory of protocols TCP, UDP, OSPF and RIP. The last two chapters are the laboratory exercises.

This work is about Hierarchical agregation and it describes its parts in the rst part of this work. Next is described its parts, main features and properties in this rst part. Document describes the possibilities of realization. Second part describes an analysis of the stability problem. Realizes the detection of failures of the Feedback target stations by the implemented protocol. The protocol is programaticly realized in JAVA language and tested in the real enviroment. In this document it is described an function of bandwidth on the speed of failure detection. The issues of detection of failure on the feedback target manager machine are discussed in this document.

The theoretical part of Master's thesis has been dealing with issues of MANET networks, issues of providing quality of services in MANET networks and analysis of various implementations of quality of services in these networks. At the start of the practical part of this thesis was described modified OLSR process model with support of quality of services. In simulation program OPNET Modeler was designed a topology of MANET network, firstly was run a simulation of this network without any support of quality of services and then was run a simulation with support of quality of services. The results of these simulations were analyzed, compared and graphically interpreted. In the next part of this thesis was designed a real MANET network with OLSR support. OLSR network communication was captured with the use of Wireshark. In the last part of this thesis was firstly described a meaning and functions of plugins in OLSR implementation and then was developed a plugin which is responsible for sending messages which contain a state of the links between nodes of MANET networks.