The aim of my diploma is to introduce the SNMP protocol designed for remote device management to the readers and present its implementation into the Opnet Modeler simulation environment. For the implementation the DiffServMIB database has been chosen, which describes the components of differentiated services mechanism. My diploma thesis describes in detail the possibilities of application of the DiffServMIB database in traffic management. The design of a simulation model, which represents the differentiated data processing in input and output direction on a router interface, is also introduced. Next, this model is implemented into the Opnet Modeler simulation environment. The goal of this simulation model is the possibility of simple configuration of individual MIB attributes. In my work I also suggest an implementation method able to interconnect the MIB database with the configuration process of the active network element - with focus on output procedures of DiffServ mechanism.

The Master´s thesis deals with the field of converged networks and their effective utilization, focusing specifically on telematic networks. For modelling of a specific application, the field of vehicle telematics has been chosen. The thesis consists of two series of simulations performed in Opnet Modeler network simulator. The first theoretic part gave an overview of protocols used in converged networks, with a more detailed description of routing protocols. The attention also centred on the mechanisms for assuring the quality of service in IP. The subsequent practical part consisted in creating the simulation of a converged telematic network in Opnet Modeler network simulator, configuration of scenarios for assuring QoS using RSVP and DSCP protocols and the simulation itself. The results of the simulations for both scenarios were compared and represented in graphic form. The second theoretic part described queueing disciplines, as well as congestion control and congestion avoidance mechanisms. The corresponding practical part compared FIFO, PQ and WFQ queueing algorithms within the same simulated converged telematic network, using DSCP protocol scenario, which gave much better results in the first series of simulations. Again, the results of the simulations were compared and represented in graphic form.

The main aim of this thesis is to familiarize with options of services using real-time data transfer in wireless networks. Theoretical part presents wireless network based on IEEE 802.11 standard and its practical use. Large part is focuses on 802.11e standart, that provides support for quality of service in wireless networks. Furthemore this thesis deals with transport and applicaton protocols supporting multimedia streaming over computer network. Second chapter is focused on analyzing real computer network with purpose in measuring parametrs influencing quality of service such as bandwith, delay, jitter and loss. Last part deals with the design of wireless network in OPNET Modeler enviroment with focus on simulating parameters that influence quality of service.

Indiana University-Purdue University Indianapolis (IUPUI) / Multi-Protocol Label Switching (MPLS) is an emerging technology which is the initial step for the forthcoming generation of communication. It uses Labels in order to identify the packets unlike the conventional IP Routing Mechanism which uses the routing table at each router to route the packet. MPLS uses the techniques of FRR with the help of RSVP/CR-LDP to overcome the link and/or node failures in the network. On the other hand there are certain limitations/drawbacks of using the above mechanisms for Failure Detection and Recovery which are multiple protocols such as RSVP/CR-LDP over OSPF/IS-IS and complex algorithms to generate backup paths since each router works individually in order to create a backup tunnel. So to overcome the listed limitations, this paper discusses a new technique for MPLS Networks which is Source Routing \cite{48}. Source Routing is the technique in which the source plays the role of directing the packet to the destination and no other router plays the role of routing the packet in the network. Using the OPNET Modeler 17.5 tool for implementing source routing when there is a network failure is performed and the results are compared by implementing RSVP/CR-LDP over the same failed network. The comparative results show that the network performance is best in the case of Source Routing implementation as compared to the RSVP and CR-LDP signaling over the MPLS Networks.

This master’s thesis deals abou the transmission of voice in communications networks. The theoretical part describes criteria for optimizing voice, such as quality of service, type of service, level of service, service type, and mean opinion score. Next I describe the Internet Protocol, comparing IPv4 and IPv6, VoIP, including security, protocols and parameters necessary for transmission. Other part is about neural networks. There are basically described the neural network, Hopfield neural network and Kohenen neural network. The research is based on a comparison of the network without ensuring the quality of service and with ensuring quality of service. Then, there are compared two types of switches. Classical switch-controlled sequentially, and switch controlled by neural networks. The overall simulation program is implemented in Opnet Modeler. The conclusion deals with the creation of laboratory tasks in this program to compare the different systems of ensuring quality of service.