P2P IPTV Measurement: A Comparison Study

With the success of P2P file sharing, new emerging P2P applications arise on the Internet for streaming content like voice (VoIP) or live video (IPTV). Nowadays, there are lots of works measuring P2P file sharing or P2P telephony systems, but there is still no comprehensive study about P2P IPTV, whereas it should be massively used in the future. During the last FIFA world cup, we measured network traffic generated by P2P IPTV applications like PPlive, PPstream, TVants and Sopcast. In this paper we analyze some of our results during the same games for the applications. We focus on traffic statistics and churn of peers within these P2P networks. Our objectives are threefold: we point out the traffic generated to understand the impact they will have on the network, we try to infer the mechanisms of such applications and highlight differences, and we give some insights about the users' behavior.Comment: 10 page

Characterization of P2P IPTV Traffic: Scaling Analysis

P2P IPTV applications arise on the Internet and will be massively used in the future. It is expected that P2P IPTV will contribute to increase the overall Internet traffic. In this context, it is important to measure the impact of P2P IPTV on the networks and to characterize this traffic. Dur- ing the 2006 FIFA World Cup, we performed an extensive measurement campaign. We measured network traffic generated by broadcasting soc- cer games by the most popular P2P IPTV applications, namely PPLive, PPStream, SOPCast and TVAnts. From the collected data, we charac- terized the P2P IPTV traffic structure at different time scales by using wavelet based transform method. To the best of our knowledge, this is the first work, which presents a complete multiscale analysis of the P2P IPTV traffic. Our results show that the scaling properties of the TCP traffic present periodic behavior whereas the UDP traffic is stationary and lead to long- range depedency characteristics. For all the applications, the download traffic has different characteristics than the upload traffic. The signaling traffic has a significant impact on the download traffic but it has negligible impact on the upload. Both sides of the traffic and its granularity has to be taken into account to design accurate P2P IPTV traffic models.Comment: 27p, submitted to a conferenc

Multilevel MDA-Lite Paris Traceroute

Since its introduction in 2006-2007, Paris Traceroute and its Multipath Detection Algorithm (MDA) have been used to conduct well over a billion IP level multipath route traces from platforms such as M-Lab. Unfortunately, the MDA requires a large number of packets in order to trace an entire topology of load balanced paths between a source and a destination, which makes it undesirable for platforms that otherwise deploy Paris Traceroute, such as RIPE Atlas. In this paper we present a major update to the Paris Traceroute tool. Our contributions are: (1) MDA-Lite, an alternative to the MDA that significantly cuts overhead while maintaining a low failure probability; (2) Fakeroute, a simulator that enables validation of a multipath route tracing tool's adherence to its claimed failure probability bounds; (3) multilevel multipath route tracing, with, for the first time, a Traceroute tool that provides a router-level view of multipath routes; and (4) surveys at both the IP and router levels of multipath routing in the Internet, showing, among other things, that load balancing topologies have increased in size well beyond what has been previously reported as recently as 2016. The data and the software underlying these results are publicly available.Comment: Preprint. To appear in Proc. ACM Internet Measurement Conference 201

Results of S5 CH tests with an ARL (Aerospace Research Laboratory) cascade

As part of a research agreement between Iowa State University of Science and Technology (ISU) and ONERA, a blade cascade designed and already tested in the United States was manufactured and tested in France. The ONERA cascade wind tunnel and mock-up are described. Attention is focused on defining the upstream conditions of the cascade. Experimental results are presented, as well as comparisons with tests conducted by Detroit Diesel Allison (DDA) in the United States

Single shot phase contrast imaging using laser-produced Betatron x-ray beams

Development of x-ray phase contrast imaging applications with a laboratory scale source have been limited by the long exposure time needed to obtain one image. We demonstrate, using the Betatron x-ray radiation produced when electrons are accelerated and wiggled in the laser-wakefield cavity, that a high quality phase contrast image of a complex object (here, a bee), located in air, can be obtained with a single laser shot. The Betatron x-ray source used in this proof of principle experiment has a source diameter of 1.7 microns and produces a synchrotron spectrum with critical energy E_c=12.3 +- 2.5 keV and 10^9 photons per shot in the whole spectrum.Comment: 3 pages, 3 figure

Chercheure hors-statut, mais ethnologue : réfléxion sur une activité professionnelle

Dans cet article sont exposées deux expériences contractuelles, l’une auprès de professionnels de l’action sociale associative en prévention spécialisée et l’autre au sein d’établissements scolaires publics, en partenariat avec des enseignants et des intervenants de professions artistiques. Le propos est d’explorer les nouvelles modalités de l’exercice du métier d’anthropologue aujourd’hui en France : comment, en réponse aux demandes des commanditaires et/ou partenaires, l’ethnologue s’efforce d’ajuster ses méthodes, ses questions et ses principes. Apparaît la nécessité, pour la discipline, d’une plus grande coopération entre anthropologues, qu’ils soient statutaires ou non, spécialistes du proche ou du lointain.This article outlines two experiences of contractual work, one with social action professionals in a preventive education-oriented association and the other in state schools, in partnership with teachers and contributors from artistic professions. The aim is to explore the new ways in which the profession of anthropologist is exercised in contemporary France: how, responding to the demands of funders and / or partners, the ethnologist tries to adjust their methods, questions and principles. The need emerges for a greater degree of cooperation between anthropologists, regardless of their status or whether they are specialists of the near or the far

Sensitivity analysis and optimization of sheet steel thickness for vibroacoustic behavior of enclosures

International audienceIn automotive applications, one of the keys to ensure weight reduction is the optimization of the sheet steel thickness. This paper presents a non-exhaustive list of sensitivity analysis methods (local, global and energy-based) allowing to determine which thicknesses could be reduced. The first results of an adaptive optimization procedure allowing reduction of the thicknesses under design constraints are also illustrated for the modal behaviour of an academic structure representing a simplified cab coupled with an acoustic cavity

FORGE enabling FIRE facilities for the eLearning community

International audienceMany engineering students at third-level institutions across the world will not have the advantage of using real-world experimentation equipment, as the infrastructure and resources required for this activity are too expensive. This paper explains how the FORGE (Forging Online Education through FIRE) FP7 project transforms Future Internet Research and Experimentation (FIRE) testbed facilities into educational resources for the eLearning community. This is achieved by providing a framework for remote experimentation that supports easy access and control to testbed infrastructure for students and educators. Moreover, we identify a list of recommendations to support development of eLearning courses that access these facilities and highlight some of the challenges encountered by FORGE

Vie de spectacles, vies en spectacle : les danseuses de revue

Les vies d’artistes examinées dans cet article sont celles de danseuses de revue, à partir de discours et d’observations recueillis lors d’une enquête réalisée dans plusieurs music-halls parisiens dans les années 1990. En organisant l’analyse suivant une chronologie inversée – depuis la reconversion jusqu’aux premiers pas dans la danse – l’objectif est de mettre en évidence, d’une part, la pluralité et l’articulation des diverses influences qui jalonnent le parcours de ces femmes dans les milieux artistiques et à l’extérieur ; et, d’autre part, la spécificité temporelle de leur activité.The artists’ lives examined in this article are those of revue dancers; in reference to discourses and observations that were made during an enquiry conducted inside several Parisian music-halls in the 1990s. While organising the analysis in the form of an inverted chronology – starting with the dancers’ new career-orientations and ending with the first steps in the world of dance – the objective is to demonstrate, on the one hand the plurality and articulation of the various influences spread along the path these women take – both inside and outside the artistic circles – and on the other hand the temporal specificity of their activity