Capturar e analisar pacotes de dados que trafegam pelas redes são tarefas essenciais para os administradores de redes. Estas tarefas ajudam na detecção de anomalias nos sistemas e na verificação do estado atual da rede. Existem várias aplicações que desempenham este papel para o sistema operacional GNU/Linux. Estes programas também exportam informações para os usuários e outras aplicações de várias maneiras. Entretanto, não exportam estas informações de forma hierárquica. Esta pesquisa propõe uma arquitetura alternativa aos sistemas atuais. Nossa arquitetura exporta pacotes de dados em uma estrutura hierárquica de arquivos e diretórios. Além disso, por se tratar de uma arquitetura modular, filtros adicionais, desenvolvidos por terceiros, podem ser adicionados ao sistema. A arquitetura proposta acompanha uma implementação de referência: o sistema de arquivos virtuais netsfs (Network Statistics File System), que funciona em espaço de núcleo (kernel space). A arquitetura e o sistema de arquivos netsfs, propostos nesta pesquisa, apresentam um método alternativo para exibir os pacotes de redes. Os resultados mostraram uma aparente melhoria no que diz respeito à vazão da rede. / Capturing and analyzing data packets flowing across networks are essential tasks for network administrators. These tasks help to detect anomalies in the systems and check the current status of a network. There are software applications for the GNU/Linux operating system which perform such tasks. These tools also export their information to users and other applications in different ways. However, current systems do not export this information in a hierarchical manner. This research introduces an alternative architecture to current systems. Our architecture exports data packets in a hierarchical structure of directories and files. Furthermore, since this is a modular architecture, additional third-party filters can be developed and loaded into the system. The proposed architecture comes with a reference implementation: the pseudo file system netsfs (Network Statistics File System), in kernel space. The architecture and the pseudo file system netsfs, developed in this research, introduce an alternative method to display data packets. Results show an apparent improvement regarding network throughput

This diploma thesis deals with the design and implementation of an application suitable for the anonymization of PCAP files. The thesis presents TCP/IP model and for each layer highlights attributes that can be used to identify real people or organizations. Some of the anonymization methods suitable to modify highlighted attributes and sensitive data are described. The implemented application uses TShark tool to parse byte data of PCAP format to JSON format that is used in the application. TShark supports lots of network protocols which allows the application to anonymize various attributes.  Anonymization process is controlled by anonymization politics that can be customized by adding new attributes or anonymization methods.

This master’s thesis is focused on behaviour of the TCP/IP protocol on free-space optical link which is affected by the effect of atmospheric turbulence. This causes fluctuation of the received optical power and therefor bit error rate changes. In the simulation model short-time bit error rate is calculated from random generated received optical signal and then used in time-domain analysis of the OMNeT++ network simulator. A buffer in transmitter is designed based on simulation results. It pauses the data transmitting in cases of FSO link outage. This method is then implemented into FPGA device.

This thesis focuses on designing and developing a centralized management and configuration solution for the thin clients offered by the OldanyGroup s.r.o. company. The purpose of this application is to simplify the thin client administration and control for customers as well as to improve the competitiveness of the whole thin client solution offered by the company.

This master’s thesis is focused on behaviour of the TCP/IP protocol on free-space optical link which is affected by the effect of atmospheric turbulence. This causes fluctuation of the received optical power and therefor bit error rate changes. In the simulation model short-time bit error rate is calculated from random generated received optical signal and then used in time-domain analysis of the OMNeT++ network simulator. A buffer in transmitter is designed based on simulation results. It pauses the data transmitting in cases of FSO link outage. This method is then implemented into FPGA device.

The growing number of players in Massively Multiplayer Online games puts a heavy load on the network infrastructure and the general-purpose CPU of the game servers. A game server’s network stack processing needs equal treatment to the game-related processing ability. It is a fact that the networkcommunication tasks on the CPU reach the same order of magnitude as the game-related tasks, and the computing capability of the CPU can be a factor that limits the maximum number of players. Therefore, CPU offloading is becoming vital. FPGAs play an essential role in dedicated computation and network communication due to their superiority in flexibility and computation-oriented efficiency. Thus, an FPGA can be a good hardware platform to implement a network stack to replace the CPU in processing the network computations. However, most commercial and open-source network stack IPs support only one or few connections. This thesis project explores a network server on FPGA, implemented in RTL, that can handle multiple connections, specialized in the TCP protocol. The design in this project adds a cached memory hierarchy that provides a filter against port numbers of multiple connections from the same application and an Application Layer Controller, based on an open-source Ethernet, to increase the number of TCP connections further. A proof of concept was built, and its performance was tested. As a result, the TCP server on the FPGA was designed to handle a maximum of 40 configurable connections, but only 25 connections could be maintained during operation due to operational latency constraints. This FPGA server solution provides a latency of 1 ms in LAN. The babbling idiot and out-of-order packet transfer tests from clientswere also performed to guarantee robustness. During testing, poor performance in Packet Loss and Packet Error Handling was noted. In the future, this issue needs to be addressed. In addition, further investigations of methods for expanding the cache need to be done to allow handling more clients. / Det växande antalet spelare i Massively Multiplayer Online-spel belastar nätverksinfrastrukturen och spelservrarnas CPU:er. En spelservers förmåga att bearbeta nätverksstacken måste behandlas lika med den spelrelaterade bearbetningsförmågan. Det är ett faktum att nätverkskommunikationsuppgifterna på processorn når samma storleksordning som de spelrelaterade uppgifterna, och processorns beräkningsförmåga kan vara en faktor som begränsar det maximala antalet spelare. Därför blir avlastning av CPU-viktig. FPGA:er spelar en viktig roll i dedikerad beräkning och nätverkskommunikation på grund av dess överlägsenhet vad gäller flexibilitet och beräkningsorienterad effektivitet. Således kan en FPGA vara en bra hårdvaruplattform för att implementera en nätverksstack, för att ersätta CPU:n vid bearbetning av nätverksberäkningsarna. Men, de flesta kommersiella och öppna källkodsnätverksstack- IP:er stöder dock bara en eller ett fåtal anslutningar. Detta examensarbete utforskar en nätverksserver på FPGA, implementerad mha RTL, som kan hantera flera anslutningar, specialiserad på TCP-protokollet. Designen i detta projekt lägger till en cachad minneshierarki som ger ett filter mot portnummer för flera anslutningar från samma applikation och en Application Layer Controller, baserad på öppen källkod för Ethernet, för att öka antalet TCP-anslutningar ytterligare. Ett proof of concept byggdes och dess prestanda testades. Som ett resultat designades TCP-servern på FPGA:n att kunna hantera maximalt 40 konfigurerbara anslutningar, men endast 25 anslutningar kunde bibehållas under drift på grund av driftsfördröjningar. Denna FPGA-serverlösning ger en latens på 1 ms i LAN. Tester inkluderande den babblande idioten och out-of-order paketöverföring från klienter utfördes också för att garantera robusthet. Under testningen noterades dålig prestanda i paketförlust och paketfelshantering. I framtiden måste denna fråga åtgärdas. Dessutom behöver ytterligare undersökningar av metoder för att utöka cachen göras för att kunna hantera fler klienter.

There are a number of known architectural patterns for TCP/IP server design. I present a survey of design choices based on some of the most common of these patterns. I have demonstrated, with working code samples, that most of these architectural patterns are readily portable between UNIX and Windows NT platforms without necessarily incurring significant performance penalties. / Computing / M. Sc. (Computer Science)

International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / This paper evaluates the performance as well as effectiveness of the High Speed Ethernet LANBased Distributed Telemetry Data Network Architecture. It also attempts to obtain a feasible solution for the Extension of LAN over High Performance Digital Modem via Routers and Bridges. With the advent of highly efficient broadband TCP/IP network and rapid growth of data traffic demand in the area of Telemetry Data Acquisition and Processing, one has to adopt a high bit rate PCM Telemetry Data Stream with the strategy of distributed task scheduling in multiprocessor environment. The proposed Telemetry System Architecture is adopted as a milestone to Modern Telemetry system. It incorporates various value added services for the performance evaluation of various flight vehicles providing authenticated data. This paper shows that by configuring the IP addresses of various nodes and router / bridges with V.35 interfaces, it is possible to extend the Telemetry Data on a local LAN to the remote LAN for display and high speed processing in real time. Necessary comparisons of performance of the existing to the proposed systems are presented.

ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, California / As traditional data acquisition systems give way to network-based data acquisition systems a new approach to instrumentation configuration, management and analysis is required. Today, most flight test programs are supported by traditional instrumentation systems and software. Pockets of network-based systems exist but are typically entirely new, closed systems. Relatively soon, test articles will emerge with a mixture of equipment. The merger of traditional and networked instrumentation is inevitable. Bridging the gap in software tools is a non-trivial task. Network-based data acquisition systems provide expanded flexibility and capabilities well beyond traditional systems. Yet pre-existing equipment requires traditional configuration and analysis tools. Traditional flight test software alone cannot fully exploit the added benefits gained from such mergers. The need exists for a new type of flight test software that handles existing instrumentation while also providing additional features to manage a network of devices. Network management is new to flight test software but a thoughtful implementation can facilitate easy transition to these modern systems. This paper explores the technologies required to satisfy traditional system configuration as well as the less understood aspects of network management and analysis. Examples of software that meet or exceed these requirements are provided.

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / This paper describes a distributed network client-server system developed for researchers to perform real-time or near-real-time analyses on ensembles of telemetry data previously done in post-flight. The client-server software approach provides extensible computing and real-time access to data at multiple remote client sites. Researchers at remote sites can share similar information as those at the test site. The system has been used successfully in numerous commercial, academic and NASA wide aircraft flight testing.