|
|
Node localization on the Internet using artificial coordinate systems
Škvor, Martin ; Molnár, Karol (referee) ; Komosný, Dan (advisor)
This thesis is focused on methods for nodes localization in Internet using latency prediction in synthetic coordinates systems. Thesis also deal with methods, which latency prediction between nodes is based on other systems. Among such a methods particularly belongs King, which uses DNS (domain name service). Furthermore, thesis deal with relevance of overlay networks in latency prediction and their use for different services. Practical part of this thesis concentrates on method for latency prediction in synthetic coordinate system Global Network positioning. There were made two programs for counting coordinates of landmarks and hosts in this system. Measurements and calculations made in this thesis, are focused to determine accuracy of latency prediction of this method and their evaluation is made at the end of thesis.
|
|
|
Simulation of data transmission latency between nodes in IP networks
Balej, Jiří ; Molnár, Karol (referee) ; Komosný, Dan (advisor)
This master thesis is focused on the delays incurred in data transmitting over IP networks. The top of the paper is devoted to points, where delay is invoked and causes of the latency. For individual sources of delay are are described the parameters that affect the usual size of latency. The next section describes the types of networks and their typical delay. In the paper are also discussed tools for measuring delay and determining the number of intermediate devices. The thesis contains results of measurements delay time in the real network. For these results are listed conclusions about the delay for one intermediate device. There is also said general ratio of crow-fly distance and calculated distance. The last part deals the simulation of delay in the NS2 program. The results of thesis are scripts that shows the relation of delay and the number of switches, routers, and the length of the path.
|
|
|
Internet coordinating systems
Krajčír, Martin ; Komosný, Dan (referee) ; Burget, Radim (advisor)
Network coordinates (NC) system is an efficient mechanism for prediction of Internet distance with limited number of measurement. This work focus on distributed coordinates system which is evaluated by relative error. According to experimental results from simulated application, was created own algorithm to compute network coordinates. Algorithm was tested by using simulated network as well as RTT values from network PlanetLab. Experiments show that clustered nodes achieve positive results of synthetic coordinates with limited connection between nodes. This work propose implementation of own NC system in network with hierarchical aggregation. Created application was placed on research projects web page of the Department of Telecommunications.
|
|
|
Monitoring of workstations in Cisco academy laboratory
Hrabal, Zdeněk ; Kubánková, Anna (referee) ; Komosný, Dan (advisor)
This thesis deals with design and implementation of a Web page that allows the manipulation with data on a server and workstation in the laboratory. It is also possible to get more information of these stations, such as installed on the virtual systems, free space on a drive or the contents of the directory. Details of the stations provide scripts written by Bc. Jiří Homolka in a Bash language. For this reason, the work also deals with the issue of scripts to run in various modes - in the background or in the pseudoterminal. Part of this work is the formation of the database structure, which allows to trace the activities on the workstations and show the history. The web is accessible form the Internet so there was given an attention to the security and protection against attempts of unauthorized intrusion. Therefore the system can login only registered users with appropriate rights or new accounts can be created or existing modified.
|
|
|
Vivaldi algorithm for Internet nodes localization
Handl, Tomáš ; Jelínek, Mojmír (referee) ; Komosný, Dan (advisor)
Diploma thesis deals with usage of artificial coordinate systems used for localization of a station on the internet and prediction of delay between the stations. There are described and compared basic properties of centralized and decentralized algorithms providing station localization on the internet and RTT prediction. More in depth are presented main representatives of both types of algorithms such as GNP, IDMAPS or Lighthouse. Central part of thesis is aimed at getting to know Vivaldi distributed algorithm. Basic principle of the algorithm for constant and variable time step, using two dimensional coordinate system with 3rd parameter height, is here outlined. Further more implementation of this algorithm as a library Vivaldi-lib in the environment of Java is implemented. Part of the thesis are simulations of behaviour of this algorithm for both variations realized on artificial networks and data obtained from PlanetLab experimental network, using simulation created program VIVALDIMONITOR.
|
|
|
Automatic configuration of workstations in Cisco academy laboratory
Homolka, Jiří ; Jelínek, Mojmír (referee) ; Komosný, Dan (advisor)
My thesis is focused on the subject of working with distant stations connected with the laboratory control of Cisco academy. Station operations, i.e. laboratory control, have been carried in the environment of the Linux operating systems. The first part of the thesis includes a description of the laboratory, its network architecture and software equipment. Also, the VMware tool is described here. VMware tool is intended for virtualization of computer stations, where the virtual station is created. In this virtual station another operating system may be run. The problems of the command interpreter, its function and possibilities are described here too. Main attention is devoted to the Bash command interpreter and to the creation of the scripts. There are descriptions of the basic tools intended for the network communication with the distant stations. Among the most important parts belong the protected communication, the production of the autentization keys as well as the tool for data recording on more stations at the same time. The description of the access rights to the files and directories is included too. The target of this thesis was to create the scripts in the Bash programming language. The scripts are focused on working with the laboratory stations. They are the sublayers of the common project for this laboratory control. They were developed for the cooperation with the the web interface and MySQL database, created by Bc. Zdeněk Hrabal. The Scripts are intended for the finding information about the stations and virtual systems, and also for the recording images and configuration files of the virtual systems at the distant stations. Recording files and directories is enabled too. The other scripts deal with the erasing and changing of the rights of the particular files and directories. Setting commads with the super-user competence is used at this place. The scripts for the switching on and off the laboratory workstations were created too. To solve the problem described above I chose to develope more scripts. Each of them subserves the particular part of the task. The form of the input and output data of the scripts was select with the reference to the cooperation with the web interface and database. The data are implemented by the form of the input and output files. The output information and the process of the carried operations are displayed through the web interface. The scripts together with the web interface are placed and run from the school server adela.utko.feec.vutbr.cz. In the thesis the settings of the access privileges for the current directories and the files of virtual systems and scripts are presented too.
|
|
|
Monitoring Application for Multicast sessions
Kopecký, Martin ; Komosný, Dan (referee) ; Šimek, Milan (advisor)
This work deals with a monitoring application for multicast sessions. The general aim is to develop the application for monitoring multicast sessions from network elements of a laboratory computer network. The first part describes possibilities of monitoring computer networks in terms of monitoring techniques and protocols. The second part contains a topology of the laboratory computer network and several basic commands for setting of the multicast in Cisco IOS. The third part is devoted to the developed application for monitoring the multicast in Java language. The last part describes the testing on an actual multicast network and an example of such testing is stated there.
|
|
|
Internet nodes localization using synthetic coordinate systems
Švéda, Jaroslav ; Jelínek, Mojmír (referee) ; Komosný, Dan (advisor)
This thesis deals with predicting the latency between two network nodes, such as the two stations, two servers or server and station. The main reason for adoption of effective latency prediction techniques is the elimination of network load caused by unnecessary repeated transmissios or by direct measurement of the latency. Of the many proposed methods of latency estimation, this thesis is focused on methods using artificial coordinate systems with primary focus on the Vivaldi algorithm. Characteristics of the latency prediction methods and properties of various coordinate systems used in practice are evaluated. The issue of the number of dimensions of space defined only by the latency matrix between nodes is also mentioned. Furthermore, some other systems, based on logical clustering of nearby nodes, are mentioned. Description of simulation software VivaldiMonitor developed as part of the thesis is included. The primary purpose is analysis of the behavior of overlay networks implementing Vivaldi algorithm with less than a few hundred nodes. The Vivaldi algorithm is assessed by several simulations carried out using the aforementioned software.
|
|
|
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.
|
|
|
Use of reliable multicast for feedback transmission in IPTV
Sobotka, David ; Novotný, Vít (referee) ; Komosný, Dan (advisor)
This Diploma thesis is focused on a part of network communication in the system of IPTV using the protocol to provide transmission of real-time multimedia RTP, specifically using the control protocol RTCP to carry voting results. The thesis further shows variants and ways of using reliable multicast and specific multicast (SSM). The main practical goal of this thesis is the program for the simulation of carrying voting results that I have created in the C++ programming language for MS Windows platform. The result is the client program receiving an inquiry from the server and reacting by application packets of the RTCP protocol. On the other side is the server program that picks up the packets and processes them. The programs run in the console mode, thus they have no graphical user interface. A user in the server program can create any inquiry and consequently send it to the client. Furthermore, the server can possibly view the current results of voting. In the client program a user can vote and possibly send another vote that will simulate other clients.
|
guest ::
