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Dynamic Metric in OSPF Networks
Mácha, Tomáš ; Orgoň, Miloš (referee) ; Bešťák, Robert (referee) ; Novotný, Vít (advisor)
Masivní vývoj Internetu vedl ke zvýšeným požadavkům na spolehlivou síťovou infrastrukturu. Efektivita komunikace v síti závisí na schopnosti směrovačů určit nejlepší cestu pro odesílání a přeposílání paketů ke koncovému zařízení. Jelikož OSPF v současné době představuje jeden z nejpoužívanějších směrovacích protokolů, jakýkoli přínos, který by pomohl udržet krok s rychle se měnícím prostředí Internetu, je velmi vítán. Významným omezením OSPF protokolu je, mimo jiné, absence informovanosti algoritmu pro výpočet metriky o aktuálním vytížení linky. Tato vlastnost představuje tzv. slabé místo, což má negativní vliv na výkonnost sítě. Z tohoto důvodu byla navržena nová metoda založená na dynamické adaptaci měnících se síťových podmínek a alternativní strategii OSPF metrik. Navržená metoda řeší problém neinformovanosti OSPF metriky o síťovém provozu a nevhodně vytížených linek, které snižují výkonnost sítě. Práce rovněž přináší praktickou realizaci, kdy vlastnosti nové metody jsou testovány a ověřeny spuštěním testů algoritmu v reálných zařízeních.
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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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Data network simulation using direct code execution
Trávníček, Michal ; Bartl, Milan (referee) ; Krkoš, Radko (advisor)
Purpose of this master thesis was to explain simulation of real network, point to the imperfection during these simulations and try to find out technologies and solutions that could improve credibility of simulation. For this purpose, network simulator ns-3 has been chosen which supports direct code execution together with Quagga software suite. Master thesis describes internet protocol IPv4, UDP protocol, basics of routing and detailed explanation of OSPF routing protocol. Focus in this thesis is also on general description of simulation, its kinds and detail explanation of discrete simulation that is used by ns-3 simulator. Next chapter explains theory of ns-3 simulator, its development, conceptual overview and objects. Direct code execution and Quagga that both help improve credibility of simulation, are described in last chapter of theoretical part of thesis. In practical part of thesis is explained how to install and configure all three implemantaions of ns-3 simulator on Ubuntu, linux distribution. On the basis of obtained knowledge, the simulation model has been designed, also there has been given detailed explanation of how to create new model of simulation and how to analyze its results for all implementation.
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IP traffic performance
Bednář, František ; Martinásek, Zdeněk (referee) ; Mácha, Tomáš (advisor)
The master thesis „IP traffic performance“ is focused on traffic testing in IP networks. Theoretical section explains routing issue in an autonomous system. This work contains a detailed description of OSPF protocol. This work also deals with behavior of a link failure. There are described mechanisms that are used to link failure detection and subsequent traffic rerouting. The next section describes mechanisms to ensure quality of service. In master thesis are explained InterServ and DiffServ mechanisms. A large part is devoted to DiffServ mechanism that ensures distinction of data flows and classification packets into different classes. The routers than can process the individual data streams with different priorities. The practical section includes the design of experimental network and creation of simulation in Opnet Modeler. By using several scenarios are compared the characteristics of routing protocols and impact of QoS on the transmission characteristics of the network. Part of practical section is the improvement of OSPF protocol by adding a new metric and implementing a new metric in software suite Quagga.
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Innovative Routing Protocols
Rouča, Tomáš ; Endrle, Pavel (referee) ; Škorpil, Vladislav (advisor)
The aim of this thesis was to get acquainted with the technology of routing data in a computer network. Thesis described in the theoretical level properties of current and past routing protocols and their use in information systems. Based on the acquired knowledge was created a simulation model of network communication in programming environment OPNET Modeler. This model analyzes the received parameters of the current protocols and their subsequent implementation in the real transmission technology using operating system Debian Linux. Finally, the transfer parameters are discussed between the simulation model and real transfer technology.
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Configuration of Open Shortest Path First routing protocol
Wolf, Jakub ; Balej, Jiří (referee) ; Komosný, Dan (advisor)
A diploma thesis introduces possibilities of the routing protocol OSPF, basic configurations and implementation into an autonomous system. A Theoretical part shows computer networks fundamentals and divide them into several groups according to standarts. It also include a part about addressing scheme in the Internet network and the ways how to subneted networks. A practical part consists of two project, that are create in a simulation program. The first simulates classroom, all the network devices and the computers are included. The second is an exam made for student to introduce OSPF in the autonomous system. The Exam uses new type of an extension, that allow student cooperate together by solving the exam. A summary contains all technique disposed in both simulations and a web presentation.
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Application of graph theory to the design and optimization data network architectures
Římský, Adam ; Trzos, Michal (referee) ; Novotný, Vít (advisor)
This masters'sthesis deals with graph theory and utilization of this theory for design and optimization of data network structures. Introduction chapter describes graph theory in general view, i.e. fundamental terms used for graph description, graph distinguishing, etc. Next part describes graph algorithms, for example a shortest path finding. After this I write about actual routing protocols where the graph algorithms are used. Last but one part deals with queuing theory and final part describes practical presentation of using graph theory for design and optimization of data network structure in Matlab programme environment.
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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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Enterprise Network Design and Simulation - Cisco Virtual Lab
Ollé, Karol ; Komosný, Dan (referee) ; Soumar, Michal (advisor)
Tématem této diplomové práce (dále jen DP) je návrh rozsáhlých podnikových sítí podle doporučení stanovených společností Cisco. Dále je realizována simulace navržené topologie prostřednictvím programů s otevřeným zdrojovým kódem a dohled nad sítí prostřednictvím programu Nagios. Úvodní část obsahuje stručné seznámení se základním rozdělením sítě do jednotlivých funkčních bloků. Druhá část se zabývá popisem jednotlivých funkčních bloků a jejich rolí v rámci celé síťové topologie. Bloky jsou dále rozděleny na jednotlivá zařízení a jsou popsány služby, které tato zařízení musí poskytovat. Třetí část DP se snaží zmapovat základní požadavky na služby, které jsou kladeny na dnešní síťové infrastruktury. Hlavní důraz je kladen na dostupnost všech nabízených služeb sítě. Jsou vyjmenovány jednotlivé protokoly druhé až třetí vrstvy OSI modelu, které zabezpečují stálou dostupnost sítě v případě selhání aktivních prvků. Čtvrtá část DP se věnuje popisu návrhu síťové topologie WAN. Pátá část obsahuje popis bezpečnostních rizik, která ohrožují dostupnost sítě, tak i popis útoků, které mají za cíl krádež identity uživatele. V šesté části DP jsou popsány programové nástroje pro zprávu sítí (Nagios, Cisco Security Device Manager) a programy, které simulují Cisco přepínače, směrovače (Dynamips & Dynagen, GNS3) a Cisco PIX firewall (PEMU). Sedmá kapitola se zabývá konkrétním návrhem rozsáhlé sítě s použitím principů, které byly zmíněny v předcházejících kapitolách. Navržená infrastruktura je dále realizována pomocí simulačních programů a tato virtuální síť dovoluje demonstrovat nastavení a chování všech popsaných protokolů a zařízení. V závěrečném shrnutí je nejdůležitější poznatek, že návrh a konfigurace rozsáhlé sítě a její realizace ve virtuálním prostředí je funkční a použitelná pro pokusné účely i pro studijní účely.
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Redundancy in data networks
Šoun, Jan ; Pavlíček, Luboš (advisor) ; Beneš, Jiří (referee)
This thesis focuses on redundancy in data networks and on technologies which are used to achieve high availability in network infrastructure. This thesis is based on industry standards published by well-known standardization authorities. One proprietary technology which can effectively replace these standards and simplify the whole network is also presented in more detail. The theoretical part individually describes all such technologies and standards. The practical part deals with an appropriate combination of these technologies and their application in a specific product environment. This work is meant to describe the whole concept of high availability in network infrastructure and should be instrumental in understanding how these technologies are deployed in practice.
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