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Quality of services in IP Telephony in Wirelass Networks
Slavíček, Tomáš ; Kyselák, Martin (referee) ; Vyoral, Josef (advisor)
The thesis deals with the principles of assurance quality of services in IP networks. The first part of the thesis describes specifications which are required by current applications for data network, and also illustrates the methods suitable for solving those requirements. The most attention is given to multimedia service VoIP whose development has not been finished from far. That theoretical knowledge implies in the second part of the thesis which analyzes the implementation of assurance QoS for the service VoIP within the standard 802.11, or more precisely, for wireless networks in general. The simulation of wireless networks within the program Opnet Modeler and the attest of the ability to assure QoS within both wireless networks and their limitations with an unswitched network are described in the next step. The current possibilities how to build up WLAN with the bearing QoS are sized up in conclusion.
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Network protocols used for management and QoS assurance in data networks
Macura, Miroslav ; Molnár, Karol (referee) ; Hošek, Jiří (advisor)
The main aim of this work was to compare network protocols used for management of active elements of the IP network and to assure QoS in data network. The bachelor work in detail describes especially SNMP protocol and possibilities of assuring quality of services in data networks. This works primary goal it to compare and analyze different versions of SNMP. The next aim of this work was to learn about structure and characteristics of the MIB database for DiffServ technology. This work studies definition of the MIB for the DiffServ technology and do the basic analyze of these MIB branches. Subsequently in programming language C/C++ create modules for creating queues. The type was First In First Out (FIFO), Priority Queuing (PQ) and Weighted Round Robin (WRR), which are used to sort packets in database DiffServ MIB. This modules are programmed with reference to his next usage in simulation environment Opnet Modeler.
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Mapping of QoS requirements on the network level
Konečný, Zbyněk ; Růčka, Lukáš (referee) ; Mácha, Tomáš (advisor)
The issue of converged networks is to ensure the sufficient quality of services along the entire length of the communication transmission. This issue is closely connected to the real-time services, such as VoIP (Voice over Internet Protocol) and videoconferencing. These services require strict adherence to quality parameters, otherwise their function is not guaranteed. This problem particulary resolves subsystem IMS (IP Multimedia Subsystem), which concluded on the basis of user profiles can provide the required quality of service. Therefore the theoretical part deals with the description of the structure of the system and protocols designed to signal the network. Various mechanisms to support quality of services in access and backbone networks are also described. The following section explains the principle of provision of quality requirements of end-user networks. In the practical part is this theoretical knowledge used for designing and configuration of the network consisting of various technologies. The resulting model is then simulated in Opnet Modeler program, which is used for designing and testing of packet networks. Each simulation shows the effect of mapping quality requirements in the different access network on technologies, which are supported in the backbone. The outcome of this work is detailed network analysis and comparison of mechanisms for implementing quality of service. The conclusion summarises all simulation outcomes.
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Simulation of network element in Matlab environment
Kuchár, Peter ; Vymazal, Michal (referee) ; Vychodil, Petr (advisor)
Master’s thesis is dedicated to the issue of network element. In the first part are described technological aspects as the internal structure of network elements and control mechanisms that provide differentiaton of services and support their quality requirements. In the first chapter are listed control mechanisms from most simple like FIFO to the more sophisticated like CBWFQ. Active queue managements are not missing and they are described in the section Riadiaci člen. Significant role in the differentiation of services have processes marking and pakets classification. The second chapter is devoted most promising standard DiffServ. Contains section devoted to architecture, paket marking, code point DSCP and the final part is devoted to the types of per-hop behavior and it is expedited forwarding EF and technique assured forwarding AF. The third chapter gives an overview common models of neural networks, their properties and assess their suitability for deployment in network elements. The routher design itself and its structure in programming environment Matlab/Simulink is the subject of the fourth chapter. Except used bloks from Simulink library is described their setting and function in the wiring. Consequently results are reviewied and conclusions drawn.
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Administration and configuration of simplified database QoS MIB
Macura, Miroslav ; Matocha, Tomáš (referee) ; Hošek, Jiří (advisor)
The main aim of this work was to study the issue of the SNMP protocol and MIB database in order to focus on management and configuration of MIB database using the SNMP protocol. The Master's thesis in detail describes especially creating a communications model of the Manager - Agent type in an OPNET Modeler. In this modeling tool we created exchange of information from the side of the Manager to the side of the Agent via SNMP packets. The Master's thesis is mainly focused on the creation of the SNMP packet according to defined rules, then on reading of information from the MIB database on the side of the Agent and saves this information to the Manager’s MIB database. Exchange of informations is realized via the messages of type GetRequest, GetNext and GetResponse. These models are programmed in language C/C++ and then implemented into the environment of OPNET Modeler.
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Effect of Network Link Failure and Alternative Route Usage on Quality of Service Assurance
Atanasčev, Petr ; Škorpil, Vladislav (referee) ; Hošek, Jiří (advisor)
Information about the differentiated services (DiffServ), the link failure problems and the alternate routes in a DiffServ domain finding are the aims of the master´s thesis to be given. Properties of the differentiated services, the usage of marking techniques in the DiffServ domain are described in the thesis. The concept of the DiffServ domain, its structure and mostly used today routing protocol OSPF are described too. The function model of the DiffServ domain has been created in the simulation environment called Opnet Modeleler on the basis of the obtained knowledge. The link failure and the following link recovery have been simulated in the model and the effects have been analyzed after that.
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Implementation of parametric models dependent on instantneous values of network traffic in OPNET Modeler simulation environment
Šibík, Štefan ; Hošek, Jiří (referee) ; Molnár, Karol (advisor)
The aim of this diploma thesis was to create an own DiffServ domain model, which is supplemented with stations generating various type of network traffic and implementation of token-bucket mechanism in router´s process model in Opnet Modeler simulation environment. DiffServ domain is made up from two edge and two core routers and includes servers and client stations generating VoIP, FTP, HTTP and database access traffic. It is described a process of distribution of traffic into different classes on edge routers of DiffServ domain along with assurance of separate handling with usage of an Assured Forwarding PHB mechanism. In point of differentiated packet processing is process model completed with generating of various statistics. The process of their creating is used to check a dropper activity, which is implemented together with token-bucket mechanism on ARP layer of the router. The functionality of the model is verified by simulation.
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Comparison of architectures of MIB system databases designed for QoS management in data networks
Jelínek, Tomáš ; Hošek, Jiří (referee) ; Molnár, Karol (advisor)
Bachelor thesis deals with Diffserv mechanism for Quality of Service in data network and goes through several parts of structure MIB database for managing Diffserv mechanism. The first chapter is introduction. I explain SNMP protocol in the second chapter. In the third chapter I deal with Quality of Service (QoS) and in the next chapter I explain Diffserv mechanism and its architecture. In fifth chapter I present possibilities of using Policy Information Base (PIB). I show several parts of MIB database in the sixth chapter. I compare two parts of MIB database and summary whole work in the last chapter.
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QoS in a computer network of VŠE
Kalina, Tomáš ; Pavlíček, Luboš (advisor) ; Beneš, Jiří (referee)
The diploma thesis is focused on analysis and deployment of Quality of Services (QoS) in a computer network of The University of Economics in Prague (VŠE). The thesis describes the main QoS technologies focusing on technology Diffserv and its deployment with using available network devices in computer network of VŠE. In thesis the needs of network services and protocols for quality of services with division into different classes of services according to priority are discussed. The thesis explains the benefits and drawbacks of deploying QoS in the environment of VŠE with regard to wired and wireless network. In the practical part recommendations are applied to the production network and subsequently the benefits of modification are evaluated.
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