Performance Research on IEEE 802.11 ac Laboratory Links

The increasing importance of wireless communications, involving electronic devices, has been widely recognized. Performance is a fundamental issue, resulting in more reliable and efficient communications. Security is also crucially important. Laboratory measurements are presented about several performance aspects of Wi-Fi IEEE 802.11ac WPA2 point-to-point links. Our study contributes to performance evaluation of this technology under WPA2 encryption, using available equipments (Cisco 2702i access points and Edimax AC 1200 adapters). New results are given from TCP and UDP experiments concerning TCP throughput versus TCP packet length, jitter and percentage datagram loss versus UDP datagram size. Comparisons are made to results obtained for corresponding IEEE 802.11n links. Conclusions are drawn about the comparative performance of the links.University of Beira Interiorinfo:eu-repo/semantics/acceptedVersio

Performance Evaluation of 5 GHz IEEE 802.11n WPA2 Laboratory Links

The increasing importance of wireless communications, involving electronic devices, has been widely recognized. Performance is a crucial issue, leading to more reliable and efficient communications. Security is also critically important. Laboratory measurements were performed about several performance aspects of Wi-Fi IEEE 802.11n WPA2 5 GHz links. Our study contributes to performance evaluation of this technology, using available equipments (HP V-M200 access points and Linksys WPC600N adapters). New detailed results are presented and discussed, namely at OSI level 4, from TCP and UDP experiments. TCP throughput is measured versus TCP packet length. Jitter and percentage datagram loss are measured versus UDP datagram size. Results are compared for both point-to-point and point-to-multipoint links. Comparisons are also made to corresponding results obtained for Open links. Conclusions are drawn about performance of the links.info:eu-repo/semantics/publishedVersio

Performance Evaluation of IEEE 802.11a 54 Mbps WEP Laboratory Links

The increasing importance of wireless communications, involving electronic devices, has been widely recognized. Performance is a fundamental issue, resulting in more reliable and efficient communications. Security is also crucially important. Laboratory measurements are presented about several performance aspects of Wi-Fi IEEE 802.11a 54 Mbps WEP point-to-point and point-to-multipoint links. Our study contributes to performance evaluation of this technology under WEP encryption, using available equipments (HP V-M200 access points and Linksys WPC600N adapters). New results are given from TCP and UDP experiments concerning TCP throughput versus TCP packet length, jitter and percentage datagram loss versus UDP datagram size. Comparisons are made to corresponding results for Open links. Conclusions are drawn about the comparative performance of the links.info:eu-repo/semantics/publishedVersio

Performance Evaluation of IEEE 802.11a 54 Mbps WPA Laboratory Links

The increasing importance of wireless communications, involving electronic devices, has been widely recognized. Performance is a fundamental issue, resulting in more reliable and efficient communications. Security is also crucially important. Laboratory measurements are presented about several performance aspects of Wi-Fi IEEE 802.11a 54 Mbps WPA point-to-point and point-to-multipoint links. Our study contributes to performance evaluation of this technology under WPA encryption, using available equipments (HP V-M200 access points and Linksys WPC600N adapters). New results are given from TCP and UDP experiments concerning TCP throughput versus TCP packet length, jitter and percentage datagram loss versus UDP datagram size. Comparisons are made to corresponding results for Open links. Conclusions are drawn about the comparative performance of the links.University of Beira Interiorinfo:eu-repo/semantics/publishedVersio

Performance Research on IEEE 802.11a 54 Mbps WPA2 Laboratory Links

The increasing importance of wireless communications, involving electronic devices, has been widely recognized. Performance is a fundamental issue, resulting in more reliable and efficient communications. Security is also crucially important. Laboratory measurements are presented about several performance aspects of Wi-Fi IEEE 802.11a 54 Mbps WPA2 point-to-point and point-to-multipoint links. Our study contributes to performance evaluation of this technology under WPA2 encryption, using available equipments (HP V-M200 access points and Linksys WPC600N adapters). New results are given from TCP and UDP experiments concerning TCP throughput versus TCP packet length, jitter and percentage datagram loss versus UDP datagram size. Comparisons are made to corresponding results for Open links. Conclusions are drawn about the comparative performance of the links.University of Beira Interiorinfo:eu-repo/semantics/publishedVersio

Large-scale DNS and DNSSEC data sets for network security research

The Domain Name System protocol is often abused to perform denial-of-service attacks. These attacks, called DNS amplification, rely on two properties of the DNS. Firstly, DNS is vulnerable to source address spoofing because it relies on the asynchronous connectionless UDP protocol. Secondly, DNS queries are usually small whereas DNS responses may be much larger than the query. In recent years, the DNS has been extended to include security features based on public key cryptography. This extension, called DNSSEC, adds integrity and authenticity to the DNS and solves a serious vulnerability in the original protocol. A downside of DNSSEC is that it may further increase the potential DNS has for amplification attacks. This disadvantage is often cited by opponents of DNSSEC as a major reason not to deploy the protocol. Until recently, however, ground truth about how serious an issue this can be was never established. This technical report describes the data sets obtained during a study we carried out to establish this ground truth. We make these data sets available as open data under a permissive Creative Commons license. We believe these data sets have a lot of value beyond our research. They, for example, allow characterisations of EDNS0 implementations, provide information on IPv6 deployment (presence or absence of AAAA records) for a large number of domains in separate TLDs, etc

Performance Studies Of IEEE 802.11 AC Laboratory Links

Wireless communications, involving electronic devices, have been increasingly important in society. Performance is a fundamental issue, resulting in more reliable and efficient communications. Security is also essential. Laboratory measurements are presented about several performance aspects of Wi-Fi IEEE 802.11ac WPA2 point-to-point links. Our study contributes to performance evaluation of this technology under WPA2 encryption, using new available equipments (Cisco 2702i access points and Edimax USB 3.0 AC 1200 adapters adapters). New results are given from TCP and UDP experiments concerning TCP throughput versus TCP packet size, jitter and percentage datagram loss versus UDP datagram size. Comparisons are made to results obtained for other IEEE 802.11 technologies. Conclusions are drawn about the comparative performance of the links.University of Beira Interior and FCT (Fundação para a Ciência e a Tecnologia)info:eu-repo/semantics/publishedVersio

GPU-based Real-time Triggering in the NA62 Experiment

Over the last few years the GPGPU (General-Purpose computing on Graphics Processing Units) paradigm represented a remarkable development in the world of computing. Computing for High-Energy Physics is no exception: several works have demonstrated the effectiveness of the integration of GPU-based systems in high level trigger of different experiments. On the other hand the use of GPUs in the low level trigger systems, characterized by stringent real-time constraints, such as tight time budget and high throughput, poses several challenges. In this paper we focus on the low level trigger in the CERN NA62 experiment, investigating the use of real-time computing on GPUs in this synchronous system. Our approach aimed at harvesting the GPU computing power to build in real-time refined physics-related trigger primitives for the RICH detector, as the the knowledge of Cerenkov rings parameters allows to build stringent conditions for data selection at trigger level. Latencies of all components of the trigger chain have been analyzed, pointing out that networking is the most critical one. To keep the latency of data transfer task under control, we devised NaNet, an FPGA-based PCIe Network Interface Card (NIC) with GPUDirect capabilities. For the processing task, we developed specific multiple ring trigger algorithms to leverage the parallel architecture of GPUs and increase the processing throughput to keep up with the high event rate. Results obtained during the first months of 2016 NA62 run are presented and discussed