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ENUM client
Srp, Jaroslav ; Bednárek, David (referee) ; Peterka, Jiří (advisor)
For node signing and addressing in the internet the 32 bits number is used - known as IP address. Because the long numbers can be hardly memorize the abstract known as domain name is established. This abstraction transforms the domain name to the IP address via DNS (the reverse process is known as reverse DNS). But not everybody owns fixed awarded IP address, that is a problem. This situation is not true for the phone numbers (fixed or mobile phones), of course. The ENUM system which is introduced in this graduation theses uses the reverse DNS to save the information (web, e-mail, sip and other addresses, phone numbers for MMS routing and such like records) to the set phone or other number. After it you can send a query to the reverse DNS for the set phone number and by return you get the mentioned informations about the phone number. As addendum are implemented the applications (client and server) and web browser plug-in that can be used for ENUM system testing, using and exploiting.
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Flow control for the IEEE 802.11 access points
Turek, Lukáš ; Peterka, Jiří (referee) ; Janeček, Jan (advisor)
Wireless networks based on IEEE 802.11 standard (Wi-Fi) are nowadays often used as a last mile of Internet connection. However the standard was not designed with this use in mind, so this kind of deployment is rife with problems. One of these problems is high latency of network under high load caused by the absence of flow control. The present work explains why flow control algorithms implemented in operating systems cannot work in Wi-Fi networks e ectively and why even the 802.11e amendment yields no solution. Subsequently an algorithm designed specially for Wi-Fi networks, which divides bandwidth equally among clients and minimizes latency while not reducing network throughput, is proposed. The function of the algorithm is con firmed by simulation in OMNeT++ environment and the algorithm is then implemented in Linux and FreeBSD operating systems.
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DNSSEC support software
Dioszegi, Matej ; Kolovratník, David (referee) ; Peterka, Jiří (advisor)
In the present work we study the development of DNSSEC system (DNS Security extensions) from its beginning to these days. Present work describes how DNSSEC helps to secure the DNS against various attacks, mainly against cache poisoning attacks. As DNSSEC was invented relatively recently and nowadays it is poorly deployed despite its importance, this work also explores present status of implementation of this system, compares existing solutions and, based on this experience, tries to implement software, that helps to deploy and spread system DNSSEC more easily.
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Safety risks of wireless networks
Vyskočil, Vladimír ; Raab, Jan (advisor) ; Peterka, Jiří (referee)
The aim of the work is to review security risks of potencial attacks upon wireless networks.To draw up detailed list and propose suffi cient methods for defend against them. Instruction, which would help to fast recognition type of an attack on given network together with instruction which would minimalize impact of these attacks on users, should be a part of the work.
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The influence of speed asymmetry on TCP/IP
Musil, Petr ; Spousta, Miroslav (referee) ; Peterka, Jiří (advisor)
The goal of present work is to determine, how does asymmetry of tranfer path (its transfer rate) influence effectiveness of TCP/IP protocols. Protocol, which is defined by the standard, is judged theoretically at first. How much does maximum exploit of tranfer rate in one direction influence load of the oposite direction of transfer path. The empirical test is made consequently. Application and transmission protocols which are often used are judged. The results are than compared with already publicated guesses and conclusions. There is going to be declared maximum ratio of transfer rates of the transfer path at the end, in condition of fully exploitation of one transfer direction.
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Autoritativní DNS server s podporou DNSSEC
Slovák, Ľuboš ; Peterka, Jiří (referee) ; Kolovratník, David (advisor)
In this thesis we design and implement an authoritative DNS server with support for DNSSEC extensions. The server is crossplatform, extensible, and with modular, objectoriented design. However, it does not support some features, such as zone transfers, dynamic updates or responding through TCP due to the constrained range of this work. We also propose a new XMLbased zone file format to be used within the application. An XML Schema grammar for the format is provided. The thesis also contains a brief introduction to the DNS protocol and its main extensions, as well as a omparison of several existing name servers.
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IMAP E-mail Client
Kundrát, Jan ; Peterka, Jiří (referee) ; Babka, Vlastimil (advisor)
This thesis describes the implementation of an advanced IMAP e-mail client, Trojita. Focusing on standards compliance, the client supports a wide range of IMAP features crucial for an efficient implementation such as IDLE notifications, server-side message parsing and caching of retrieved body data for offline operation. Connecting to the IMAP server is supported over TCP sockets, optionally secured via the TLS encryption, as well as through a local process. Basic message composition and sending via both SMTP and a local sendmail instance is supported. The target platform is the Qt framework on Linux, but the application is reasonably portable.
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Analysis of SLD DNS servers state
Šťastný, Petr ; Obdržálek, David (referee) ; Peterka, Jiří (advisor)
The publication contains a brief introduction into the system of domain names on the Internet (DNS) and into DNS protocol and its functioning. The main part is a methodology for systematic examination of a domain name and its name servers, offering criteria for checking validity of DNS records and functionality and availability of DNS servers. This methodology is then implemented as a web application that allows us to perform an on-line analysis of a domain name and the evaluation of discovered errors and other problems. The second part of the implementation is a tool for bulk analysis of large number of domain names, which was subsequently used for analysis of all domain names under TLD CZ; its short results are mentioned in the end of the work.
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Monitorování serverů zapojených do výpočetního GRIDu
Burdík, Michal ; Peterka, Jiří (referee) ; Chudoba, Jiří (advisor)
This thesis researches available software products for monitoring of computational farms. The Golias computational farm in the Institute of Physics of the Academy of Sciences of the Czech Republic served as a testbase. The main contribution of this work was a speci c recon guration of the existing monitoring system Nagios and the installation of a monitoring tool Ganglia. Reusable extension components were developed because of inadequacies in existing monitoring products, especially in the area of presentation and data analysis. Based on the data prepared using the extension components an analysis of the performance of Golias farm's computational nodes has been undertaken, which now serves as a baseline for decisions regarding further development and optimization of the farm.
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