# Grid'5000 user report for Patrick Loiseau

## User information

Patrick Loiseau (users, user, lyon user)
More user information in the user management interface.

## Experiments

• Metrology on Grid5000 (Networking) [in progress]
Description: We want to analyse network traffic on the grid in terms of statistical properties like Long Range Dependance, self-similarity, etc. We especially want to understand the impact of statistic characteristics of the traffic on the QoS. The experiments consist in creating traffic with some imposed characteristics (flow size distribution, etc.) and looking at the resulting arrival and bandwidth processes and the QoS.
Results: not yet
• Investigating self-similarity and heavy tailed distributions on a large scale experimental facility (Networking) [achieved]
Description: After seminal work by Taqqu et al. relating self-similarity to heavy tail distributions, a number of research articles verified that aggregated Internet traffic time series show self-similarity and that Internet attributes, like WEB file sizes and flow lengths, were heavy tailed. However, the validation of the theoretical prediction relating self-similarity and heavy tails remains unsatisfactorily addressed, being investigated either using numerical or network simulations, or from uncontrolled web traffic data. Notably, this prediction has never been conclusively verified on real networks using controlled and stationary scenarii, prescribing specific heavy-tail distributions, and estimating confidence intervals. In the present work, we use the potential and facilities offered by the large-scale, deeply reconfigurable and fully controllable experimental Grid5000 instrument, to investigate the prediction observability on real networks. To this end we organize a large number of controlled traffic circulation sessions on a nation-wide real network involving two hundred independent hosts. We use a FPGA-based measurement system, to collect the corresponding traffic at packet level. We then estimate both the self-similarity exponent of the aggregated time series and the heavy-tail index of flow size distributions, independently. Comparison of these two estimated parameters, enables us to discuss the practical applicability conditions of the theoretical prediction.
Results:
• TCP traffic self-similarity under loss (Networking) [in progress]
Description: Over the last decade, many research efforts have been devoted to the study of aggregated traffic time series collected at the core of networks. The pioneering works by Paxson and Leland showed that the Poisson hypothesis, which is relevantly used in phone networks, was not suitable to describe computer networks. Instead, self-similarity was proved a much more appropriate paradigm. Then, the theoretical work from Taqqu and collaborators identified the heavy-tailed nature of the file size distribution as a possible origin for the observed self-similarity. In addition, it gave the exact relation between the self-similarity index and the tail index that should be observed when the sources behavior is modeled with the ON/OFF model. Despite a controversial debate on the question, it has then been more recently stated that the TCP congestion control mechanism cannot be responsible for the self-similarity observed in the large time scales. On the opposite side, we show in this work that when the file size is heavy-tailed, the TCP congestion control mechanism under sufficiently high loss can annihilate the self-similarity that would be observed without any loss. For this work, we use large scale controled experiments performed on Grid5000. Independant TCP sources send files in an ON/OFF scenario with a heavy-tailed ON periods; and a constant loss rate is created via UDP cross traffic.
Results:

## Publications

• Contributions to the analysis of scaling behavior and quality of service in networks: experimental and theoretical aspects [2009] (national) EntryType: phdthesis Resotos: web Author: Loiseau, Patrick Month: December School: \'Ecole Normale Sup\'erieure de Lyon X-editorial-board: no X-proceedings: no X-international-audience: no
• \emphMetroflux: a high performance system for very fine-grain flow analysis [2009] (national) EntryType: inproceedings Resotos: web Author: Loiseau, Patrick and Gonçalves, Paulo and Guillier, Romaric and Imbert, Matthieu and Goga, Oana and Kodama, Yuetsu and Vicat-Blanc Primet, Pascale Booktitle: Grid'5000 Spring School Address: Nancy, France Month: April X-editorial-board: yes X-proceedings: no X-international-audience: no
• V\'erification du lien entre auto-similarit\'e et distributions \a queues lourdes sur un dispositif grande \'echelle [2008] (national) EntryType: inproceedings Resotos: web Author: Loiseau, Patrick and Gonçalves, Paulo and Dewaele, Guillaume and Borgnat, Pierre and Abry, Patrice and Vicat-Blanc Primet, Pascale Booktitle: 9 i{\e}me Atelier en Evaluation de Performances Address: Aussois, France Month: June X-editorial-board: yes X-proceedings: yes X-international-audience: no Abstract: In this short paper (in french), we present the results of a series a experiments designed to validate the link between self-similarity and heavy tails in a real network environment. The experiments are performed on Grid5000, a large scale experimental facility.
• Investigating self-similarity and heavy-tailed distributions on a large scale experimental facility [2010] (international) EntryType: article Resotos: web Author: Loiseau, Patrick and Gonçalves, Paulo and Dewaele, Guillaume and Borgnat, Pierre and Abry, Patrice and Vicat-Blanc Primet, Pascale Journal: IEEE/ACM Transactions on Networking Month: Note: to appear X-editorial-board: yes X-proceedings: no X-international-audience: yes Abstract: After the seminal work by Taqqu et al. relating self-similarity to heavy-tailed distributions, a number of research articles verified that aggregated Internet traffic time series show self-similarity and that Internet attributes, like Web file sizes and flow lengths, were heavy-tailed. However, the validation of the theoretical prediction relating self-similarity and heavy tails remains unsatisfactorily addressed, being investigated either using numerical or network simulations, or from uncontrolled Web traffic data. Notably, this prediction has never been conclusively verified on real networks using controlled and stationary scenarii, prescribing specific heavy-tailed distributions, and estimating confidence intervals. With this goal in mind, we use the potential and facilities offered by the large-scale, deeply reconfigurable and fully controllable experimental Grid5000 instrument, to investigate the prediction observability on real networks. To this end we organize a large number of controlled traffic circulation sessions on a nation-wide real network involving two hundred independent hosts. We use a FPGA-based measurement system, to collect the corresponding traffic at packet level. We then estimate both the self-similarity exponent of the aggregated time series and the heavy-tail index of flow size distributions, independently. On the one hand, our results complement and validate with a striking accuracy some conclusions drawn from a series of pioneer studies. On the other hand, they bring in new insights on the controversial role of certain components of real networks.
• Modeling TCP Throughput: an Elaborated Large-Deviations-Based Model and its Empirical Validation [2010] (international) EntryType: inproceedings Author: Loiseau, Patrick and Gonçalves, Paulo and Barral, Julien and Vicat-Blanc Primet, Pascale Month: Booktitle: Performance Address: Namur, Belgium
• Automated Traffic measurements and analysis in Grid5000 [2009] (international) EntryType: misc Resotos: web Author: Loiseau, Patrick and Guillier, Romaric and Goga, Oana and Imbert, Matthieu and Gonçalves, Paulo and Vicat-Blanc Primet, Pascale Note: ACM Sigmetrics/Performance demonstration contest (\textbf{Best Student Demonstration Award}) Month: June X-editorial-board: yes X-proceedings: no X-international-audience: yes
• Maximum Likelihood Estimation of the Flow Size Distribution Tail Index from Sampled Packet Data [2009] (international) EntryType: inproceedings Resotos: web Author: Loiseau, Patrick and Gonçalves, Paulo and Girard, Stéphane and Forbes, Florence and Vicat-Blanc Primet, Pascale Booktitle: ACM Sigmetrics/Performance Address: Seattle, WA, USA Month: X-editorial-board: yes X-proceedings: yes X-international-audience: yes Abstract: In the context of network traffic analysis, we address the problem of estimating the tail index of flow (or more generally of any group) size distribution from the observation of a sampled population of packets (individuals). We give an exhaustive bibliography of the existing methods and show the relations between them. The main contribution of this work is then to propose a new method to estimate the tail index from sampled data, based on the resolution of the maximum likelihood problem. To assess the performance of our method, we present a full performance evaluation based on numerical simulations, and also on a real traffic trace corresponding to internet traffic recently acquired.
• Metroflux: A high performance system for analyzing flow at very fine-grain [2009] (international) EntryType: inproceedings Resotos: web Author: Loiseau, Patrick and Gonçalves, Paulo and Guillier, Romaric and Imbert, Matthieu and Kodama, Yuetsu and Vicat-Blanc Primet, Pascale Booktitle: TridentCom Month: Address: Washington DC, USA X-editorial-board: yes X-proceedings: yes X-international-audience: yes Abstract: Researches in network traffic analysis embrace a large diversity of goals and are based on a variety of methodologies and tools. To have a better insight on the real nature and on the evolution of network traffic we argue that fine-grain analysis of real traffic traces have to complement simulations studies as well as coarse grain measurement performed by classical flow measurement systems. In particular, packet level measurements and analysis are needed. However, such methodologies are resource consuming and require very high performance devices to be operational in real high speed networks. In this paper we present the \emph{Metroflux} system which aims at providing researchers and network operators with a very flexible and accurate packet-level traffic analysis toolkit configured for 1~Gbps and 10~Gbps speed links. This system is based on the GtrcNet FPGA-based device technology and on specific statistical analysis tools. We show the potential and the facilities offered by the \emph{Metroflux} system coupled with the \emph{Grid5000} large scale experimental platform and the Network eXperiment Engine (\emph{NXE}) we have developed. We illustrate the application of the \emph{Metroflux} system with the practical validation of the theoretical prediction relating self-similarity and heavy tails given by Taqqu theorem. We also illustrate several usages of this toolset, such as the investigation of conditions under which several traffic theories apply, as well as studies on traffic, protocols and systems interactions.
• How TCP can kill Self-Similarity [2008] (international) EntryType: inproceedings Author: Loiseau, Patrick and Gonçalves, Paulo and Vicat-Blanc Primet, Pascale Note: Euro-NF workshop: Traffic Engineering and Dependability in the Network of the Future, VTT, Finland Month: September
• Investigating self-similarity and heavy-tailed distributions on a large scale experimental facility [2008] (international) EntryType: techreport Author: Patrick Loiseau and Paulo Gon{\c c}alves and Guillaume Dewaele and Pierre Borgnat and Patrice Abry and and Pascale Vicat-Blanc Primet Institution: INRIA Number: 6472 Month: March
• Metroflux: A fully operational high speed metrology platform [2008] (international) EntryType: inproceedings Resotos: web Author: Loiseau, Patrick and Gonçalves, Paulo and Kodama, Yuetsu and Vicat-Blanc Primet, Pascale Booktitle: Euro-NF workshop: New trends in modeling, quantitative methods and measurements, in cooperation with NET-COOP Address: Thomson Paris Research Labs, France Month: X-editorial-board: yes X-proceedings: no X-international-audience: yes Abstract: Modern experimental researches on networks are facing some difficulties due to the emergence of very high speed links (10~Gbps). It raises the challenging issue of monitoring these very high speed links at a fine grain. In this paper, we present MetroFlux: a fully operational metrology platform which enables to capture the traffic at packet level on a very high speed link. This platform is based on GNET10, a FPGA based hardware network emulator. The architecture of this capture device is exposed, and we extend all the offered possibilities. The utilization of MetroFlux is then presented in two situations. Firstly it was used to monitor a core link of a fully controlled experiment grid platform, Grid5000, which enables to choose a lot of parameters (aggregation level, congestion, source flow size distribution, etc.). Secondly, the capture device was used to monitor a production link. In both cases, we give examples of results that can be achived thanks to the use of MetroFlux.

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last update: 2010-07-30 10:44:02