270,158 research outputs found

    Monitoring very high speed links

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    On the Exploration of FPGAs and High-Level Synthesis Capabilities on Multi-Gigabit-per-Second Networks

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    Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Escuela Politécnica Superior, Departamento de Tecnología Electrónica y de las Comunicaciones. Fecha de lectura: 24-01-2020Traffic on computer networks has faced an exponential grown in recent years. Both links and communication equipment had to adapt in order to provide a minimum quality of service required for current needs. However, in recent years, a few factors have prevented commercial off-the-shelf hardware from being able to keep pace with this growth rate, consequently, some software tools are struggling to fulfill their tasks, especially at speeds higher than 10 Gbit/s. For this reason, Field Programmable Gate Arrays (FPGAs) have arisen as an alternative to address the most demanding tasks without the need to design an application specific integrated circuit, this is in part to their flexibility and programmability in the field. Needless to say, developing for FPGAs is well-known to be complex. Therefore, in this thesis we tackle the use of FPGAs and High-Level Synthesis (HLS) languages in the context of computer networks. We focus on the use of FPGA both in computer network monitoring application and reliable data transmission at very high-speed. On the other hand, we intend to shed light on the use of high level synthesis languages and boost FPGA applicability in the context of computer networks so as to reduce development time and design complexity. In the first part of the thesis, devoted to computer network monitoring. We take advantage of the FPGA determinism in order to implement active monitoring probes, which consist on sending a train of packets which is later used to obtain network parameters. In this case, the determinism is key to reduce the uncertainty of the measurements. The results of our experiments show that the FPGA implementations are much more accurate and more precise than the software counterpart. At the same time, the FPGA implementation is scalable in terms of network speed — 1, 10 and 100 Gbit/s. In the context of passive monitoring, we leverage the FPGA architecture to implement algorithms able to thin cyphered traffic as well as removing duplicate packets. These two algorithms straightforward in principle, but very useful to help traditional network analysis tools to cope with their task at higher network speeds. On one hand, processing cyphered traffic bring little benefits, on the other hand, processing duplicate traffic impacts negatively in the performance of the software tools. In the second part of the thesis, devoted to the TCP/IP stack. We explore the current limitations of reliable data transmission using standard software at very high-speed. Nowadays, the network is becoming an important bottleneck to fulfill current needs, in particular in data centers. What is more, in recent years the deployment of 100 Gbit/s network links has started. Consequently, there has been an increase scrutiny of how networking functionality is deployed, furthermore, a wide range of approaches are currently being explored to increase the efficiency of networks and tailor its functionality to the actual needs of the application at hand. FPGAs arise as the perfect alternative to deal with this problem. For this reason, in this thesis we develop Limago an FPGA-based open-source implementation of a TCP/IP stack operating at 100 Gbit/s for Xilinx’s FPGAs. Limago not only provides an unprecedented throughput, but also, provides a tiny latency when compared to the software implementations, at least fifteen times. Limago is a key contribution in some of the hottest topic at the moment, for instance, network-attached FPGA and in-network data processing

    A Novel Satellite Architecture for the Next Generation of Earth Observation Satellites Supporting Rapid Alerts

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    The EO-ALERT European Commission H2020 project proposes the definition, development, and verification and validation through ground hardware testing, of a next-generation Earth Observation (EO) data processing chain. The proposed data processing chain is based on a novel flight segment architecture that moves EO data processing elements traditionally executed in the ground segment to on-board the satellite, with the aim of delivering EO products to the end user with very low latency. EO-ALERT achieves, globally, latencies below five minutes for EO products delivery, and below one minute in realistic scenarios. The proposed EO-ALERT architecture is enabled by on-board processing, recent improvements in processing hardware using Commercial Off-The-Shelf (COTS) components, and persistent space-to-ground communications links. EO-ALERT combines innovations in the on-board elements of the data chain and the communications, namely: on-board reconfigurable data handling, on-board image generation and processing for the generation of alerts (EO products) using Machine Learning (ML) and Artificial Intelligence (AI), on-board AI-based data compression and encryption, high-speed on-board avionics, and reconfigurable high data rate communication links to ground, including a separate chain for alerts with minimum latency and global coverage. This paper presents the proposed architecture, its hardware realization for the ground testing in a representative environment and its performance. The architecture’s performance is evaluated considering two different user scenarios where very low latency (almost-real-time) EO product delivery is required: ship detection and extreme weather monitoring/nowcasting. The hardware testing results show that, when implemented using COTS components and available communication links, the proposed architecture can deliver alerts to the end user with a latency below five minutes, for both SAR and Optical missions, demonstrating the viability of the EO-ALERT architecture. In particular, in several test scenarios, for both the TerraSAR-X SAR and DEIMOS-2 Optical Very High Resolution (VHR) missions, hardware testing of the proposed architecture has shown it can deliver EO products and alerts to the end user globally, with latency lower than one-point-five minutes

    The Level-0 Muon Trigger for the LHCb Experiment

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    A very compact architecture has been developed for the first level Muon Trigger of the LHCb experiment that processes 40 millions of proton-proton collisions per second. For each collision, it receives 3.2 kBytes of data and it finds straight tracks within a 1.2 microseconds latency. The trigger implementation is massively parallel, pipelined and fully synchronous with the LHC clock. It relies on 248 high density Field Programable Gate arrays and on the massive use of multigigabit serial link transceivers embedded inside FPGAs.Comment: 33 pages, 16 figures, submitted to NIM

    Deep Space Network information system architecture study

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    The purpose of this article is to describe an architecture for the Deep Space Network (DSN) information system in the years 2000-2010 and to provide guidelines for its evolution during the 1990s. The study scope is defined to be from the front-end areas at the antennas to the end users (spacecraft teams, principal investigators, archival storage systems, and non-NASA partners). The architectural vision provides guidance for major DSN implementation efforts during the next decade. A strong motivation for the study is an expected dramatic improvement in information-systems technologies, such as the following: computer processing, automation technology (including knowledge-based systems), networking and data transport, software and hardware engineering, and human-interface technology. The proposed Ground Information System has the following major features: unified architecture from the front-end area to the end user; open-systems standards to achieve interoperability; DSN production of level 0 data; delivery of level 0 data from the Deep Space Communications Complex, if desired; dedicated telemetry processors for each receiver; security against unauthorized access and errors; and highly automated monitor and control

    A Survey on Communication Networks for Electric System Automation

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    Published in Computer Networks 50 (2006) 877–897, an Elsevier journal. The definitive version of this publication is available from Science Direct. Digital Object Identifier:10.1016/j.comnet.2006.01.005In today’s competitive electric utility marketplace, reliable and real-time information become the key factor for reliable delivery of power to the end-users, profitability of the electric utility and customer satisfaction. The operational and commercial demands of electric utilities require a high-performance data communication network that supports both existing functionalities and future operational requirements. In this respect, since such a communication network constitutes the core of the electric system automation applications, the design of a cost-effective and reliable network architecture is crucial. In this paper, the opportunities and challenges of a hybrid network architecture are discussed for electric system automation. More specifically, Internet based Virtual Private Networks, power line communications, satellite communications and wireless communications (wireless sensor networks, WiMAX and wireless mesh networks) are described in detail. The motivation of this paper is to provide a better understanding of the hybrid network architecture that can provide heterogeneous electric system automation application requirements. In this regard, our aim is to present a structured framework for electric utilities who plan to utilize new communication technologies for automation and hence, to make the decision making process more effective and direct.This work was supported by NEETRAC under Project #04-157

    The Ultralight project: the network as an integrated and managed resource for data-intensive science

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    Looks at the UltraLight project which treats the network interconnecting globally distributed data sets as a dynamic, configurable, and closely monitored resource to construct a next-generation system that can meet the high-energy physics community's data-processing, distribution, access, and analysis needs
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