The Experts below are selected from a list of 41226 Experts worldwide ranked by ideXlab platform
Gianni Antichi - One of the best experts on this subject based on the ideXlab platform.
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OFLOPS-Turbo: Testing the next-Generation OpenFlow switch
2015Co-Authors: Charalampos Rotsos, Gianni Antichi, Marc Bruyère, Philippe Owezarski, Andrew W. MooreAbstract:The heterogeneity barrier breakthrough achieved by the OpenFlow protocol is currently paced by the variability in performance semantics among network devices, which reduces the ability of applications to take complete advantage of programmable control. As a result, control applications remain conservative on performance requirements in order to be generalizable and trade performance for explicit state consistency in order to support varying performance behaviours. In this paper we argue that network control must be optimized towards network device capabilities and network managers and application developers must perform informed design decision using accurate switch performance profiles. This becomes highly critical for modern OpenFlow-enabled 10 GbE optical switches which significantly elevate switch performance requirements. We present OFLOPS-Turbo, the integration of the OFLOPS switch evaluation platform, with the OSNT platform, a hardware-accelerated Traffic Generation and capture system supporting lossless 10 GbE functionality. Using OFLOPS-Turbo, we conduct an evaluation of flow table manipulation capabilities in a representative collection of 10 GbE production OpenFlow switch devices and interpret the evolution of OpenFlow support by comparison with historical data.
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Enabling Performance Evaluation Beyond 10 Gbps
Proc. ACM SIGCOMM (Poster demo session), 2015Co-Authors: Gianni Antichi, Andrew W. MooreAbstract:Despite network monitoring and testing being critical for computer networks, current solutions are both extremely ex- pensive and inexible. This demo presents OSNT (www.osnt.org), a community- driven, high-performance, open-source Traffic generator and capture system built on top of the NetFPGA-10G board which enables flexible network testing. The platform sup- ports full line-rate Traffic Generation regardless of packet size across the four card ports, packet capture filtering and packet thinning in hardware and sub-μsec time precision in Traffic Generation and capture, corrected using an external GPS device. Furthermore, it provides a software APIs to test the dataplane performance of multi-10G switches, providing a starting point for a number of different test cases. OSNT flexibility is further demonstrated through the OFLOPS-turbo platform: An integration of OSNT with the OFLOPS OpenFlow switch performance evaluation plat- form, enabling control and data plane evaluation of 10G switches. This demo showcases the applicability of the OSNT platform to evaluate the performance of legacy and OpenFlow- enabled networking devices, and demonstrates it using commercial switches. © 2015 ACM.
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osnt open source network tester
IEEE Network, 2014Co-Authors: Gianni Antichi, Marc Bruyère, Muhammad Shahbaz, Yilong Geng, Noa Zilberman, Adam Covington, Nick Mckeown, Nick Feamster, Bob Felderman, Michaela BlottAbstract:Despite network monitoring and testing being critical for computer networks, current solutions are both extremely expensive and inflexible. Into this lacuna we launch the Open Source Network Tester, a fully open source Traffic generator and capture system. Our prototype implementation on the NetFPGA-10G supports 4 × 10 Gb/s Traffic Generation across all packet sizes, and Traffic capture is supported up to 2 × 10Gb/s with naive host software. Our system implementation provides methods for scaling and coordinating multiple generator/capture systems, and supports 6.25 ns timestamp resolution with clock drift and phase coordination maintained by GPS input. Additionally, our approach has demonstrated lower-cost than comparable commercial systems while achieving comparable levels of precision and accuracy; all within an open-source framework extensible with new features to support new applications, while permitting validation and review of the implementation.
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BRUNO: A high performance Traffic generator for network processor
2008 International Symposium on Performance Evaluation of Computer and Telecommunication Systems, 2008Co-Authors: Gianni Antichi, Andrea Di Pietro, Domenico Ficara, Stefano Giordano, Gregorio Procissi, Fabio VitucciAbstract:The current software tools for Traffic Generation suffer from poor performance in terms of frames per second and timing/rate accuracy, because of the intrinsic limitations of the PC architecture. This paper proposes a different approach, based on a cooperative PC/NP architecture: an advanced software tool runs on a host PC and instructs the processing engines of an Intel IXP2400 network processor, which take care of the actual Traffic Generation. This way, we keep the high flexibility of PC solutions while outperforming them in terms of packet rate. In addition, a time correction mechanism is introduced, in order to improve the system precision in Traffic models reproduction. The adoption of such a mechanism is justified through statistical analysis of the overall system: the experiments carried out prove the effectiveness of this approach in reducing the mean interdeparture time error. Moreover, they show the capability of BRUNO in generating 1.5 Mpps with high accuracy.
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Design of a High Performance Traffic Generator on Network Processor
2008 11th EUROMICRO Conference on Digital System Design Architectures Methods and Tools, 2008Co-Authors: Gianni Antichi, Andrea Di Pietro, Domenico Ficara, Stefano Giordano, Gregorio Procissi, Fabio VitucciAbstract:Evaluating the performance of high-speed networks is a critical task due to the lack of reliable tools to generate Traffic workloads at high rates. The current open-source software tools are not suitable to deal with high-speed networks as they present poor performance in terms of generated frames per second and scarce timing/rate accuracy in Traffic Generation. These issues are due to the intrinsic limitations of the PC architecture, for which these tools are designed. This paper proposes a different approach based on the Intel Network Processor IXP2400. The design aims to maintain the high flexibility of PC solutions while outperforming them in terms of throughput and packet rate. This is obtained by combining a general-purpose PC with the processing units of a network processor.
Valentina Bracaglia - One of the best experts on this subject based on the ideXlab platform.
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air transport and high speed rail competition environmental implications and mitigation strategies
Transportation Research Part A-policy and Practice, 2016Co-Authors: Tiziana Dalfonso, Changmin Jiang, Valentina BracagliaAbstract:We build a duopoly model to shed light on the environmental impact of HSR-air transport competition, capturing the effects of induced demand, schedule frequency and HSR speed. The net environmental effect can be negative since there is a the trade-off between the substitution effect – how many passengers using the HSR are shifted from air transport – and the Traffic Generation effect – how much new demand is generated by the HSR. We conduct a simulation study based on the London-Paris market where HSR has served 70% of the market. The introduction of HSR is detrimental to LAP, while it is beneficial to GHG emissions. HSR entry increases neither LAP nor GHG emissions when the ratio between HSR and air transport emissions is relatively low. Moreover, competition is more likely to be detrimental to the environment when the weight of the social welfare in HSR objective function is high. Since the magnitude of the environmental friendliness of HSR compared to air transport hinges on the mix of energy sources used to generate the electricity (which is heavily constrained by the country in which HSR operates), regulators should assess the implications of HSR entry taking into account the energy policy and mitigation strategies available to transport modes.
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would competition between air transport and high speed rail benefit environment and social welfare
Transportation Research Part B-methodological, 2015Co-Authors: Tiziana Dalfonso, Changmin Jiang, Valentina BracagliaAbstract:We develop a duopoly model to analyze the impact of air transport and high-speed rail (HSR) competition on the environment and social welfare. We show that the introduction of HSR may have a net negative effect on the environment, since it may result in additional demand, i.e., there is a trade-off between the substitution effect and the Traffic Generation effect. Furthermore, if environmental externalities are taken into account when assessing social welfare, the surplus measure may be higher when only air transport serves the market than when the two modes compete. When the airline and the HSR operator decide frequencies, the airline reduces the aircraft size in order to keep load factors high while offering lower frequency and carrying fewer passengers. In these circumstances, the introduction of HSR may be beneficial to the environment on a per seat basis only if the market size is large enough. When the HSR operator decides speed, it has incentive to keep it at the maximum level in order to reduce travel time. When the increase in the emissions of HSR due to the increase in the speed of the train is sufficiently high, the overall level of emissions grows after the introduction of HSR. Therefore, there can be a trade-off between the attractiveness of the service due to reduced travel time and the effects on the environment.
Tiziana Dalfonso - One of the best experts on this subject based on the ideXlab platform.
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air transport and high speed rail competition environmental implications and mitigation strategies
Transportation Research Part A-policy and Practice, 2016Co-Authors: Tiziana Dalfonso, Changmin Jiang, Valentina BracagliaAbstract:We build a duopoly model to shed light on the environmental impact of HSR-air transport competition, capturing the effects of induced demand, schedule frequency and HSR speed. The net environmental effect can be negative since there is a the trade-off between the substitution effect – how many passengers using the HSR are shifted from air transport – and the Traffic Generation effect – how much new demand is generated by the HSR. We conduct a simulation study based on the London-Paris market where HSR has served 70% of the market. The introduction of HSR is detrimental to LAP, while it is beneficial to GHG emissions. HSR entry increases neither LAP nor GHG emissions when the ratio between HSR and air transport emissions is relatively low. Moreover, competition is more likely to be detrimental to the environment when the weight of the social welfare in HSR objective function is high. Since the magnitude of the environmental friendliness of HSR compared to air transport hinges on the mix of energy sources used to generate the electricity (which is heavily constrained by the country in which HSR operates), regulators should assess the implications of HSR entry taking into account the energy policy and mitigation strategies available to transport modes.
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would competition between air transport and high speed rail benefit environment and social welfare
Transportation Research Part B-methodological, 2015Co-Authors: Tiziana Dalfonso, Changmin Jiang, Valentina BracagliaAbstract:We develop a duopoly model to analyze the impact of air transport and high-speed rail (HSR) competition on the environment and social welfare. We show that the introduction of HSR may have a net negative effect on the environment, since it may result in additional demand, i.e., there is a trade-off between the substitution effect and the Traffic Generation effect. Furthermore, if environmental externalities are taken into account when assessing social welfare, the surplus measure may be higher when only air transport serves the market than when the two modes compete. When the airline and the HSR operator decide frequencies, the airline reduces the aircraft size in order to keep load factors high while offering lower frequency and carrying fewer passengers. In these circumstances, the introduction of HSR may be beneficial to the environment on a per seat basis only if the market size is large enough. When the HSR operator decides speed, it has incentive to keep it at the maximum level in order to reduce travel time. When the increase in the emissions of HSR due to the increase in the speed of the train is sufficiently high, the overall level of emissions grows after the introduction of HSR. Therefore, there can be a trade-off between the attractiveness of the service due to reduced travel time and the effects on the environment.
Antonio Pescape - One of the best experts on this subject based on the ideXlab platform.
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Do you trust your software-based Traffic generator?
IEEE Communications Magazine, 2010Co-Authors: Alessio Botta, Alberto Dainotti, Antonio PescapeAbstract:Networking research often relies on synthetic Traffic Generation in its experimental activities; from Generation of realistic workload to active measurements. Often researchers adopt software-based generators because of their flexibility. However, despite the increasing number of features (e.g., replication of complex Traffic models), they are still suffering problems that can undermine the correctness of experiments: what is generated is sometimes far from what is requested by the operator. In this article, by analyzing four of the most used packet-level Traffic generators in literature, we show how they fail to follow the requested profiles. Moreover, we identify and discuss key concepts affecting their accuracy as well as mechanisms commonly adopted to improve it. This contribution goes toward improving the knowledge researchers and practitioners should have of the tools used in experimental works, and at the same time illustrates some directions for the use and design of software-based Traffic generators.
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analysis and experimentation of an open distributed platform for synthetic Traffic Generation
International Workshop on Variable Structure Systems, 2004Co-Authors: Donato Emma, Antonio Pescape, Giorgio VentreAbstract:This work presents an open distributed platform for Traffic Generation that we called distributed Internet Traffic generator (D-ITG), capable of producing Traffic (network transport and application layer) and of accurately replicating appropriate stochastic processes for both IDT (inter departure time) and PS (packet size) random variables. We implemented two different versions of our distributed generator. In the first one, a log server is in charge of recording the information transmitted by senders and receivers and these communications are based either on TCP or UDP. In the other one, senders and receivers make use of the MPI library. A complete performance analysis among centralized version and the two versions of D-ITG is presented. To our knowledge, no similar works are available.
Moore Andrew - One of the best experts on this subject based on the ideXlab platform.
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Enabling Performance Evaluation Beyond 10 Gbp
ACM SIGCOMM Computer Communication Review, 2015Co-Authors: Antichi Gianni, Rostos Charalampos, Moore AndrewAbstract:Despite network monitoring and testing being critical for computer networks, current solutions are both extremely expensive and inflexible. This demo presents OSNT (www.osnt.org), a community-driven, high-performance, open-source Traffic generator and capture system built on top of the NetFPGA-10G board which enables flexible network testing. The platform supports full line-rate Traffic Generation regardless of packet size across the four card ports, packet capture filtering and packet thinning in hardware and sub-msec time precision in Traffic Generation and capture, corrected using an external GPS device. Furthermore, it provides a software APIs to test the dataplane performance of multi-10G switches, providing a starting point for a number of different test cases. OSNT flexibility is further demonstrated through the OFLOPS-turbo platform: an integration of OSNT with the OFLOPS OpenFlow switch performance evaluation platform, enabling control and data plane evaluation of 10G switches. This demo showcases the applicability of the OSNT platform to evaluate the performance of legacy and OpenFlow-enabled networking devices, and demonstrates it using commercial switches.We thank the NetFPGA team and community. This project is jointly supported by the EPSRC INTERNET Project EP/H040536/1, the EPSRC TOUCAN project EP/L020009/1 and by the European Union’s Horizon 2020 research and innovation programme under the ENDEAVOUR project (grant agreement 644960).This is the author accepted manuscript. The final version is available from ACM via http://dx.doi.org/10.1145/2785956.279003
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OFLOPS-Turbo: Testing the next-Generation OpenFlow switch
IEEE International Conference on Communications, 2015Co-Authors: Rotsos C, Antichi Gianni, Bruyere M, Owezarski P, Moore AndrewAbstract:The heterogeneity barrier breakthrough achieved by the OpenFlow protocol is currently paced by the variability in performance semantics among network devices, which reduces the ability of applications to take complete advantage of programmable control. As a result, control applications remain conservative on performance requirements in order to be generalizable and trade performance for explicit state consistency in order to support varying performance behaviours. In this paper we argue that network control must be optimized towards network device capabilities and network managers and application developers must perform informed design decision using accurate switch performance profiles. This becomes highly critical for modern OpenFlow-enabled 10 GbE optical switches which significantly elevate switch performance requirements. We present OFLOPS-Turbo, the integration of the OFLOPS switch evaluation platform, with the OSNT platform, a hardware-accelerated Traffic Generation and capture system supporting lossless 10 GbE functionality. Using OFLOPS-Turbo, we conduct an evaluation of flow table manipulation capabilities in a representative collection of 10 GbE production OpenFlow switch devices and interpret the evolution of OpenFlow support by comparison with historical data.This work was jointly supported by the EPSRC INTERNET Project EP/H040536/1 and the Defense Advanced Research Projects Agency (DARPA) and the Air Force Research Laboratory (AFRL), under contract FA8750-11- C-0249. The views, opinions, and/or findings contained in this article/presentation are those of the author/ presenter and should not be interpreted as representing the official views or policies, either expressed or implied, of the Defense Advanced Research Projects Agency or the Department of Defense.This is the final version of the article. It first appeared from IEEE via http://dx.doi.org/10.1109/ICC.2015.724921
