References of "Leduc, Guy"      in Complete repository Arts & humanities   Archaeology   Art & art history   Classical & oriental studies   History   Languages & linguistics   Literature   Performing arts   Philosophy & ethics   Religion & theology   Multidisciplinary, general & others Business & economic sciences   Accounting & auditing   Production, distribution & supply chain management   Finance   General management & organizational theory   Human resources management   Management information systems   Marketing   Strategy & innovation   Quantitative methods in economics & management   General economics & history of economic thought   International economics   Macroeconomics & monetary economics   Microeconomics   Economic systems & public economics   Social economics   Special economic topics (health, labor, transportation…)   Multidisciplinary, general & others Engineering, computing & technology   Aerospace & aeronautics engineering   Architecture   Chemical engineering   Civil engineering   Computer science   Electrical & electronics engineering   Energy   Geological, petroleum & mining engineering   Materials science & engineering   Mechanical engineering   Multidisciplinary, general & others Human health sciences   Alternative medicine   Anesthesia & intensive care   Cardiovascular & respiratory systems   Dentistry & oral medicine   Dermatology   Endocrinology, metabolism & nutrition   Forensic medicine   Gastroenterology & hepatology   General & internal medicine   Geriatrics   Hematology   Immunology & infectious disease   Laboratory medicine & medical technology   Neurology   Oncology   Ophthalmology   Orthopedics, rehabilitation & sports medicine   Otolaryngology   Pediatrics   Pharmacy, pharmacology & toxicology   Psychiatry   Public health, health care sciences & services   Radiology, nuclear medicine & imaging   Reproductive medicine (gynecology, andrology, obstetrics)   Rheumatology   Surgery   Urology & nephrology   Multidisciplinary, general & others Law, criminology & political science   Civil law   Criminal law & procedure   Criminology   Economic & commercial law   European & international law   Judicial law   Metalaw, Roman law, history of law & comparative law   Political science, public administration & international relations   Public law   Social law   Tax law   Multidisciplinary, general & others Life sciences   Agriculture & agronomy   Anatomy (cytology, histology, embryology...) & physiology   Animal production & animal husbandry   Aquatic sciences & oceanology   Biochemistry, biophysics & molecular biology   Biotechnology   Entomology & pest control   Environmental sciences & ecology   Food science   Genetics & genetic processes   Microbiology   Phytobiology (plant sciences, forestry, mycology...)   Veterinary medicine & animal health   Zoology   Multidisciplinary, general & others Physical, chemical, mathematical & earth Sciences   Chemistry   Earth sciences & physical geography   Mathematics   Physics   Space science, astronomy & astrophysics   Multidisciplinary, general & others Social & behavioral sciences, psychology   Animal psychology, ethology & psychobiology   Anthropology   Communication & mass media   Education & instruction   Human geography & demography   Library & information sciences   Neurosciences & behavior   Regional & inter-regional studies   Social work & social policy   Sociology & social sciences   Social, industrial & organizational psychology   Theoretical & cognitive psychology   Treatment & clinical psychology   Multidisciplinary, general & others     Showing results 21 to 40 of 155     1 2 3 4 5 6 7     A Practical Bytecode Interpreter for Programmable Routers on Network ProcessorMartin, Sylvain ; Leduc, Guy in Computer Networks (2009), 53(15), 2740-2751WASP is a programmable router platform that allows end-hosts to store ephemeral state in routers along the path of IP flows and to execute packet-attached bytecode that processes this data. We exploit ... [more ▼]WASP is a programmable router platform that allows end-hosts to store ephemeral state in routers along the path of IP flows and to execute packet-attached bytecode that processes this data. We exploit lessons from past active network research and our knowledge of network processors to design a minimal interpreter that favours language restrictions over run-time checks. WASP provides safety with limited performance penalty through predictable execution time and bounded usage of memory and network resources. WASP is expressive enough to enable several applications including statistics collection and service discovery. It can also detect common trunk of two Internet paths and exchange local measurements about these paths. We propose a robust implementation on the IXP2400 network processor, and evaluate its performance through short benchmark programs against native functions hard-coded in the router. We achieve latencies below 7$\,\mu{s}$, i.e. less than the reference IPv4 forwarding latency, and throughputs approaching 800\,kpps per core, which competes with, and sometimes even outperforms, native programs. We further exploit our results to give hints on further improving resource usage and guidelines on management of ephemeral stores in high-speed networks. [less ▲]Detailed reference viewed: 53 (16 ULg) Triangle Inequality Violation Avoidance in Internet Coordinate SystemsLiao, Yongjun ; Leduc, Guy Poster (2009, August 24)Detailed reference viewed: 90 (15 ULg) Detecting Triangle Inequality Violations in Internet Coordinate SystemsKaafar, Mohamed Ali; Cantin, François ; Gueye, Cheikh Ahmadou Bamba et alin Future Networks 2009 (2009, June 18)Internet Coordinate Systems (ICS) have been proposed as a method for estimating delays between hosts without direct measurement. However, they can only be accurate when the triangle inequality holds for ... [more ▼]Internet Coordinate Systems (ICS) have been proposed as a method for estimating delays between hosts without direct measurement. However, they can only be accurate when the triangle inequality holds for Internet delays. Actually Triangle Inequality Violations (TIVs) are frequent and are likely to remain a property of the Internet due to routing policies or path inflation. In this paper we propose methods to detect TIVs with high confidence by observing various metrics such as the relative estimation error on the coordinates. Indeed, the detection of TIVs can be used for mitigating their impact on the ICS itself, by excluding some disturbing nodes from clusters running their own ICS, or more generally by improving their neighbor selection mechanism. [less ▲]Detailed reference viewed: 69 (28 ULg) Detecting Triangle Inequality Violations in Internet Coordinate Systems by Supervised LearningLiao, Yongjun ; Kaafar, Mohamed Ali; Gueye, Bamba et alin Lecture Notes in Computer Science (2009, May 12), 5550Internet Coordinates Systems (ICS) are used to predict Internet distances with limited measurements. However the precision of an ICS is degraded by the presence of Triangle Inequality Violations (TIVs ... [more ▼]Internet Coordinates Systems (ICS) are used to predict Internet distances with limited measurements. However the precision of an ICS is degraded by the presence of Triangle Inequality Violations (TIVs). Simple methods have been proposed to detect TIVs, based e.g. on the empirical observation that a TIV is more likely when the distance is underestimated by the coordinates. In this paper, we apply supervised machine learning techniques to try and derive more powerful criteria to detect TIVs. We first show that (ensembles of) Decision Trees (DTs) learnt on our datasets are very good models for this problem. Moreover, our approach brings out a discriminative variable (called OREE), which combines the classical estimation error with the variance of the estimated distance. This variable alone is as good as an ensemble of DTs, and provides a much simpler criterion. If every node of the ICS sorts its neighbours according to OREE, we show that cutting these lists after a given number of neighbours, or when OREE crosses a given threshold value, achieves very good performance to detect TIVs. [less ▲]Detailed reference viewed: 122 (30 ULg) BGP-aware IGP Link Weight Optimization in Presence of Route ReflectorsBalon, Simon ; Leduc, Guy in IEEE INFOCOM 2009 (2009, April)The first generation of IGP Link Weight Optimizers (LWOs) was based on presumably invariant intra-domain traffic matrices only, ignoring the fact that updating link weights had a side effect on these ... [more ▼]The first generation of IGP Link Weight Optimizers (LWOs) was based on presumably invariant intra-domain traffic matrices only, ignoring the fact that updating link weights had a side effect on these traffic matrices due to hot-potato routing, thus result- ing in suboptimal link weight settings, and sometimes to very bad performance. The second generation of IGP LWOs, referred to as BGP-aware LWOs, has been able to optimize link weights while taking hot-potato effects into account. However, these tools relied on the complete visibility assumption fulfilled by e.g. a full-mesh iBGP configu- ration. This paper proposes a third generation LWO, still BGP-aware, but also able to work with iBGP con- figurations based on route reflectors, which usually hide some reachability information from routers. This partial visibility may cause various problems, including path deflections (i.e., the actual egress router is not the expected one), which may in turn create forwarding loops. Our LWO embeds a BGP routing solver which can always predict the actual egress router, even when route reflectors are used. It can also forbid solutions leading to path deflection. Its efficiency is evaluated on a real dataset, and compared to other LWOs. [less ▲]Detailed reference viewed: 120 (21 ULg) Routing Based on Delivery Distributions in Predictable Disruption Tolerant NetworksFrançois, Jean-Marc; Leduc, Guy in Ad hoc Networks (2009), 7(1), 219-229This article studies disruption tolerant networks (DTNs) where each node knows the probabilistic distribution of contacts with other nodes. It proposes a framework that allows one to formalize the ... [more ▼]This article studies disruption tolerant networks (DTNs) where each node knows the probabilistic distribution of contacts with other nodes. It proposes a framework that allows one to formalize the behaviour of such a network. It generalizes extreme cases that have been studied before where (a) either nodes only know their contact frequency with each other or (b) they have a perfect knowledge of who meets who and when. This paper then gives an example of how this framework can be used; it shows how one can find a packet forwarding algorithm optimized to meet the ‘delay/bandwidth consumption’ tradeoff: packets are duplicated so as to (statistically) guarantee a given delay or delivery probability, but not too much so as to reduce the bandwidth, energy, and memory consumption. [less ▲]Detailed reference viewed: 34 (6 ULg) Interpreted Active Packets for Ephemeral State Processing RoutersMartin, Sylvain ; Leduc, Guy in Lecture Notes in Computer Science (2009), 4388We propose WASP (lightweight and World-friendly Active packets for ephemeral State Processing), a new active platform based on Ephemeral State designed to allow bytecode interpretation on programmable ... [more ▼]We propose WASP (lightweight and World-friendly Active packets for ephemeral State Processing), a new active platform based on Ephemeral State designed to allow bytecode interpretation on programmable datapath elements. We designed WASP to be a good compromise between flexibility (e.g. offering solutions in quality-adaptive multimedia flows, service discovery or mobility support) and safety (i.e. protection of router and network resource). [less ▲]Detailed reference viewed: 24 (7 ULg) A Self-Organized clustering scheme for overlay networksCantin, François ; Gueye, Cheikh Ahmadou Bamba ; Kaafar, Mohamed Ali et alin Lecture Notes in Computer Science (2008, December), 5343Hierarchical approaches, where nodes are clustered based on their network distances, have been shown to allow for robust and scalable topology-aware overlays. Moreover, recent research works have shown ... [more ▼]Hierarchical approaches, where nodes are clustered based on their network distances, have been shown to allow for robust and scalable topology-aware overlays. Moreover, recent research works have shown that cluster-based deployments of Internet Coordinates Systems (ICS), where nodes estimate both intra-cluster and inter-cluster distances, do mitigate the impact of Triangle Inequality Violations (TIVs) on the distance predictions, and hence offer more accurate internet latency estimations. To allow the construction of such useful clusters we propose a self-organized distributed clustering scheme. For better scalability and efficiency, our algorithm uses the coordinates of a subset of nodes, known by running an ICS system, as first approximations of node positions. We designed and evaluated two variants of this algorithm. The first one, based on some cooperation among nodes, aims at reducing the expected time to construct clusters. The second variant, where nodes are selfish, aims at reducing the induced communication overhead. [less ▲]Detailed reference viewed: 54 (20 ULg) Overlay Routing using Coordinate SystemsCantin, François ; Gueye, Cheikh Ahmadou Bamba ; Kaafar, Mohamed Ali et alPoster (2008, December)We address the problem of finding indirect overlay paths that reduce the latency between pairs of nodes in an overlay. To this end we propose to rely on an Internet Coordinate System (ICS), namely Vivaldi ... [more ▼]We address the problem of finding indirect overlay paths that reduce the latency between pairs of nodes in an overlay. To this end we propose to rely on an Internet Coordinate System (ICS), namely Vivaldi, to estimate RTTs and help find these interesting detours. We define two initial criteria to illustrate our approach and assess their true/false positive rates. [less ▲]Detailed reference viewed: 102 (48 ULg) Combined Intra- and Inter-domain Traffic Engineering using Hot-Potato Aware Link Weights OptimizationBalon, Simon ; Leduc, Guy in ACM SIGMETRICS Performance Evaluation Review (2008), 36(1), 441-442A well-known approach to intradomain traffic engineering consists in finding the set of link weights that minimizes a network-wide objective function for a given intradomain traffic matrix. This approach ... [more ▼]A well-known approach to intradomain traffic engineering consists in finding the set of link weights that minimizes a network-wide objective function for a given intradomain traffic matrix. This approach is inadequate because it ignores a potential impact on interdomain routing due to hot-potato routing policies. This may result in changes in the intradomain traffic matrix that have not been anticipated by the link weights optimizer, possibly leading to degraded network performance.