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Speech signal transmission over unreliable networks
Rozman, Jiří ; Krajsa, Ondřej (referee) ; Polívka, Michal (advisor)
This thesis deals with analysis of internet telephony. It is fosuced on analysis of VoIP over metalic and wireless network using virtual telephonic switch-board with hardware and software phones and also alternative programs to transmit voice such as Skype and Windows Messenger. It also deals with simulating parameters that influance voice transmission like jitter, latency packet loss. WANem system was used for this simulation. In the end it is focused on the problem of providing flawless voice communication over internet, specially providing Quality of Service.
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Multimedia data transmission in mobile networks and assurence of QoS
Bortel, Martin ; Novotný, Vít (referee) ; Havelka, Dušan (advisor)
In Bachelor’s Thesis - Multimedia Data Transmission over Mobile Networks and assurance of QoS basic characteristics of UMTS network are described. At the beginning of the thesis types of data and their properties are explained. Then the attention is paid to data transfers through the network and assurance of QoS. The principle of OSI model, function of RLC protocol and types of QoS classes are mentioned in this section. PDP Contexts and their application in the network are pointed out. At the end of the theoretical part the structure of network is described and the functionality of its parts is depicted. Closure of the thesis is focused on the simulations of UMTS network model in OPNET Modeler environment.
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Traffic Shaping in High Speed Networks in DPDK
Doležal, Pavel ; Fukač, Tomáš (referee) ; Vrána, Roman (advisor)
This bachelor thesis is focused on traffic shaping in high speed networks. It presents framework DPDK, which can be used for fast packet processing. General traffic shaping mechanisms are described as well as traffic shaping in Linux using program tc. It also introduces a design and implementation of traffic shaper using DPDK framework for networks with 10 Gbps bandwidth. The traffic shaper uses a complex mechanism of hierarchical token bucket. The system was tested using high speed traffic generator Spirent.
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Design of Advanced Simulation Model of DiffServ Technology in Opnet Modeler Environment
Machata, Tomáš ; Mlýnek, Petr (referee) ; Hošek, Jiří (advisor)
The aim of this bachelor´s thesis was to get acquainted with the problems of ensuring quality of service in IP networks. The greatest attention was devoted to DiffServ technology and methods for the identification and classification of network traffic at edge routers. Simulation model of DiffServ technology was created in OPNET Modeler environment. This model contains a number of edge and core routers, switches, servers and client stations on which it is generating a network traffic (VoIP, HTTP, FTP and databases). Individual applications were included in different classes at the edge routers of DiffServ domain and the different behavior of the applications was ensured with usage of an Assured Forwarding PHB. It was found by using simulations which method of classification packets is the best for the quality of service. Furthermore the model of DiffServ technology was extended about alternative route. OSPF routing protocol was configured here and has been studied the impact of failure of the main line and using of alternative routes to the quality of service.
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User Oriented QoS System
Plchot, Oldřich ; Matoušek, Petr (referee) ; Kašpárek, Tomáš (advisor)
This master's thesis deals with the possibilities how to guarantee the quality of service in the area of computer networks using a GNU/Linux operating system. This work compares and evaluates tools which are necessary to guarantee the quality of service. The goal of this work is to discuss the advantages and disadvantages of these tools and to design a system which handles the problem of quality of service. Designed system uses a heuristics, which allows the user to set up the quality of service system without studying specific properties of communication protocols on the network or application layer. This work also includes a theoretical introduction into the quality of service and computer networks.
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QoS in IP network with the help of OMNeT++ simulation tool
Hudec, Lukáš ; Mlýnek, Petr (referee) ; Růčka, Lukáš (advisor)
The content of this thesis is giving information about the network simulator OMNeT++ and its superstructure INET Framework. In this thesis a sample simulation of IP network with the help of simulation package INET Framework is realized on this theme. The thesis also deals with analysis of possibilities, how to assure quality service in IP networks and subsequently implementation quality of service in surrounding of network simulator OMNeT++ and its superstructure INET Framework. The implementation is accomplished by two methods. The first method is implementation of differential service, in other words DiffServ, with the help of change the behavior of output. This change rest in sorting of data packets to different queues by their device priority. The second method shows principles of the technology MPLS and also function code protocol OSPF. The MPLS technology is realized by special routers with implemented moduls reservation protocol.
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Evaluation of service quality parameters in data networks
Gregor, Lukáš ; Zeman, Václav (referee) ; Novotný, Vít (advisor)
The bachelor thesis deals about the issues of IP networks. About technologies for ensuring the quality of services, that is necessary to implement in today’s IP networks, due to the large increase of data flows. The bachelor thesis is oriented especially on technologies IntServ, DiffServ, MPLS and requirements of different types of services to the qualitative parameters of data networks. The aim of practical part is to devise a laboratory exercise for measuring qualitative parameters of different services under various condition in the intermediate network. Emulation of network parameters is carried out using emulation tool WANem with GNU Linux core.
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Simulation of QoS models in Opnet IT Guru environment
Zapletal, Lukáš ; Molnár, Karol (referee) ; Kacálek, Jan (advisor)
The main goal of this work is description and following simulation of operating with support of QoS technology in OPNET IT Guru programme. The bachelor’s work contains a theoreticall description of providing the quality of service by force of integrated and differentiated services models and also of the MPLS protocol. The work is particularly focused on IntServ model and its reservation with assistance of the RSVP protocol. The simulation in OPNET IT Guru programme has also been included in the work. Process for constituent parameters setting-up and its characterization for both the models are described thoroughly in work’s supplement. As for the differentiated services, the simulation is performed by confrontation of a voice service in two scripts. In case of differentiated services the mechanisms for tagging of packets and the treatment method have been demonstrated on inside and border routers. Operating types are simulated in ftp, e-mail and voice applications. Verification of authenticity and validity results of objects setting-up is being performed by simulation in OPNET IT Guru environment, Academic Edition version 9.1. Grafical results have also been gained by the simulation.
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Design of Switch Used in Modern Communication Networks
Mojžiš, Ľubomír ; Novotný, Bohumil (referee) ; Škorpil, Vladislav (advisor)
This diploma thesis deals with switching components of modern communication networks. A switch architecture focused on the quality of service is described in this paper and there are two switch models designed and simulated in the simulating program MATLAB-SIMULINK. The first model is based on classic switching and the other one is controlled by neural network. A laboratory exercise suitable for communication networks education is created in this paper on the basis of designed models.
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