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Efficient Communication in Multi-GPU Systems
Špeťko, Matej ; Jaroš, Jiří (referee) ; Vaverka, Filip (advisor)
After the introduction of CUDA by Nvidia, the GPUs became devices capable of accelerating any general purpose computation. GPUs are designed as parallel processors which posses huge computation power. Modern supercomputers are often equipped with GPU accelerators. Sometimes single GPU performance is not enough for a scientific application and it needs to scale over multiple GPUs. During the computation, there is a need for the GPUs to exchange partial results. This communication represents computation overhead and it is important to research methods of the effective communication between GPUs. This means less CPU involvement, lower latency and shared system buffers. This thesis is focused on inter-node and intra-node GPU-to-GPU communication using GPUDirect technologies from Nvidia and CUDA-Aware MPI. Subsequently, k-Wave toolbox for simulating the propagation of acoustic waves is introduced. This application is accelerated by using CUDA-Aware MPI. Peer-to-peer transfer support is also integrated to k-Wave using CUDA Inter-process Communication.
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Effective data searching on the Internet
Tlusťák, Miloš ; Vlach, Jan (referee) ; Lambertová, Petra (advisor)
This master´s thesis is concerned in problematic of data searching on the Internet which is very actual. It focuses mainly how centralized, decentralized and hybrid searching work. This paper also compares advantages and disadvantages of these methods and describes principles and syntaxes of most-used search engines. Possibilities of use intelligent search agents are shown here as well. The practical part of this thesis is dedicated to development and testing of specialized application for searching. This program enable user to harvest contacts of companies in accordance to defined key-words and creates database file from obtained contacts.
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Detection of P2P Networks
Březina, Matej ; Matoušek, Petr (referee) ; Tobola, Jiří (advisor)
This document deals with design, implementation and testing of software system for detecting p2p (peer-to-peer) networks based on combination of BPF prefiltering and POSIX regular expressions packet payload matching with known p2p protocol communications. The proposed detection system includes a database with some rules of most effuse p2p protocols in format resembling to definitions for L7-filter classifier. The application is implemented in C, runs in userspace and is targeted to all POSIX compatible platforms. The combination of detector with user attached QoS controlling is complete solution for traffic reduction of common p2p protocols.
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Efficient Communication in Multi-GPU Systems
Špeťko, Matej ; Jaroš, Jiří (referee) ; Vaverka, Filip (advisor)
After the introduction of CUDA by Nvidia, the GPUs became devices capable of accelerating any general purpose computation. GPUs are designed as parallel processors which posses huge computation power. Modern supercomputers are often equipped with GPU accelerators. Sometimes the performance or the memory capacity of a single GPU is not enough for a scientific application. The application needs to be scaled into multiple GPUs. During the computation there is need for the GPUs to exchange partial results. This communication represents computation overhead. For this reason it is important to research the methods of the effective communication between GPUs. This means less CPU involvement, lower latency, shared system buffers. Inter-node and intra-node communication is examined. The main focus is on GPUDirect technologies from Nvidia and CUDA-Aware MPI. Subsequently k-Wave toolbox for simulating the propagation of acoustic waves is introduced. This application is accelerated by using CUDA-Aware MPI.
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Properties of the physical layer of ZigBee
Humpolík, Tomáš ; Frýza, Tomáš (referee) ; Prokopec, Jan (advisor)
The ZigBee standart works on using physical and data link layer of IEEE 802.15.4 standart. Three bands were defined (2.4GHz, 915MHz and 868MHz). There was also number of physical layers defined, each of them using one of the three bands and number of modulation and spreading functions. This thesis is focused first of all on specification 2,4GHz physical layer, which is world-wide used because this band can be used (with observace of the local rules) without license. Thesis is in its first part focused on modulation function, as well on used spreading functions and number of channels for each physical layer. In the second part is paid attention to demonstration kit by ATMEL Corporation, which enables associate a simple network in star topology and using the network for demonstration of simple functions of associated devices, and kit by Radiocrafts corporation, which is used in laboratory work. Laboratory work is focused on characteristics measurement during data transfer.
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Cryptovirology and Future of Malware
Prchal, Josef ; Říha, Zdeněk (referee) ; Cvrček, Daniel (advisor)
Malware is connected to information technology. They influence each other. The aim of this thesis is to describe various types of this software and give a brief account of its history and development. It also discusses main trends of this area and tries to foretell the future development.
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Secure peer-to-peer communication system
Eliáš, Luboš ; Koutný, Martin (referee) ; Cvrk, Lubomír (advisor)
The main aim of this master's thesis is to implement a common, secure and peer-to-peer communication system. The system has ability to automatically establish and run a secure end-to-end connection. It has this ability even if a network address translator is in the way to the destination system, without need of any explicit configuration of this translator. The security procedures of this system are in a transparent manner masked from individual applications, which had to solve this challenge in their own way. A responsibility for a security is delegate to an application-independent subsystem working within the core of an operating system. The security of this subsystem is based on capturing the outbound and inbound IP packets and their authentication and encryption. The system was successfully implemented in MS Windows XP operating system, in programming language C++. Transfer rate of communication tunnel in different network bandwidth speeds was measured. Result shows, that in the case of use the system on standard PC sold nowadays is practically no decrease of the transfer rate in comparison to a common channel.
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Network Synchronization of Data under OS Windows
Hellar, Jan ; Trchalík, Roman (referee) ; Očenášek, Pavel (advisor)
This thesis deals with an implementation of a tool for file synchronization over a network for OS Windows. It also illustrates what issues are associated with synchronization of files, such as collision detection and resolution and the issue of setting up connection between two devices over the internet when connected to the internet via NAT devices. Thesis presents factual implementation of collision resolver and application of methods for NAT traversal. By testing the final solution correctness of collision resolver and NAT traversal technique was verified. Results of testing are discussed and possible extensions are proposed.
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Cryptocurrency Node Monitoring
Zaujec, Andrej ; Grégr, Matěj (referee) ; Veselý, Vladimír (advisor)
Cielom tejto bakalarskej prace je monitorovanie uzlov v Bitcoin peer-to-peer sieti a odhadnutie velkosti siete v danom case. Monitorovanie uzlov zahrnna zbieranie metadat o danych uzloch a tiez aj vytvaranie zaznamov cinnosti o tom ako dlho boli jednotlive uzly sucastou siete. Navrhnute riesenie vyuziva Bitcoin Core klienta bez dalsich modifikacii na zistenie vsetkych informacii o sieti a uzloch. Implementovana platforma umoznuje zbieranie metadat (verzia protokolu, verzia agenta, ponukane sluzby, IP adresa, cislo portu) o najdenych uzloch. Taktiez je schopna ziskavat informacie o tom, ktore uzly sa nachadzaju v sieti v danom case. Vytvorene API ponuka zozbierane data z platformy. Kazda komponenta platformy je zapuzdrena v Docker kontajneroch co umoznuje jednoduche nasadenie celej platformy v priebehu niekolkych minut.
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Distributed multimedia service
Jaroš, Martin ; Malina, Lukáš (referee) ; Číka, Petr (advisor)
Diplomová práce se zabývá návrhem a realizací distribuované komunikační služby v reálném čase, jejím cílem je sestavit základní strukturu pro aplikace digitálního přenosu zvuku a videa v rámci klient-klient topologie sítě. Práce definuje komunikační protokol a popisuje jeho implementaci. Důraz je také kladen na zabezpečení pomocí moderních kryptografických metod. Realizace navazuje na stávající řešení přičemž využívá především svobodného softwaru.
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