Results 1  10
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201
Fair endtoend windowbased congestion control
 IEEE/ACM TRANS. ON NETWORKING
, 2000
"... In this paper, we demonstrate the existence of fair endtoend windowbased congestion control protocols for packetswitched networks with first comefirst served routers. Our definition of fairness generalizes proportional fairness and includes arbitrarily close approximations of maxmin fairness. T ..."
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Cited by 467 (3 self)
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In this paper, we demonstrate the existence of fair endtoend windowbased congestion control protocols for packetswitched networks with first comefirst served routers. Our definition of fairness generalizes proportional fairness and includes arbitrarily close approximations of maxmin fairness. The protocols use only information that is available to end hosts and are designed to converge reasonably fast. Our study is based on a multiclass fluid model of the network. The convergence of the protocols is proved using a Lyapunov function. The technical challenge is in the practical implementation of the protocols.
FAST TCP: Motivation, Architecture, Algorithms, Performance
, 2004
"... We describe FAST TCP, a new TCP congestion control algorithm for highspeed longlatency networks, from design to implementation. We highlight the approach taken by FAST TCP to address the four difficulties, at both packet and flow levels, which the current TCP implementation has at large windows. W ..."
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Cited by 273 (18 self)
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We describe FAST TCP, a new TCP congestion control algorithm for highspeed longlatency networks, from design to implementation. We highlight the approach taken by FAST TCP to address the four difficulties, at both packet and flow levels, which the current TCP implementation has at large windows. We describe the architecture and characterize the equilibrium and stability properties of FAST TCP. We present experimental results comparing our first Linux prototype with TCP Reno, HSTCP, and STCP in terms of throughput, fairness, stability, and responsiveness. FAST TCP aims to rapidly stabilize highspeed longlatency networks into steady, efficient and fair operating points, in dynamic sharing environments, and the preliminary results are promising.
A Duality Model of TCP and Queue Management Algorithms
 IEEE/ACM Trans. on Networking
, 2002
"... We propose a duality model of congestion control and apply it to understand the equilibrium properties of TCP and active queue management schemes. Congestion control is the interaction of source rates with certain congestion measures at network links. The basic idea is to regard source rates as p ..."
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Cited by 239 (34 self)
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We propose a duality model of congestion control and apply it to understand the equilibrium properties of TCP and active queue management schemes. Congestion control is the interaction of source rates with certain congestion measures at network links. The basic idea is to regard source rates as primal variables and congestion measures as dual variables, and congestion control as a distributed primaldual algorithm carried out over the Internet to maximize aggregate utility subject to capacity constraints. The primal iteration is carried out by TCP algorithms such as Reno or Vegas, and the dual iteration is carried out by queue management such as DropTail, RED or REM. We present these algorithms and their generalizations, derive their utility functions, and study their interaction.
Analysis and Design of an Adaptive Virtual Queue (AVQ) Algorithm for Active Queue Management
 In Proceedings of ACM SIGCOMM
, 2001
"... Virtual Queuebased marking schemes have been recently proposed for AQM (Active Queue Management) in Internet routers. We consider a particular scheme, which we call the Adaptive Virtual Queue (AVQ), and study its following properties: stability in the presence of feedback delays, its ability to mai ..."
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Cited by 206 (19 self)
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Virtual Queuebased marking schemes have been recently proposed for AQM (Active Queue Management) in Internet routers. We consider a particular scheme, which we call the Adaptive Virtual Queue (AVQ), and study its following properties: stability in the presence of feedback delays, its ability to maintain small queue lengths and its robustness in the presence of extremely short flows (the socalled web mice). Using a mathematical tool motivated by the earlier work of Hollot et al, we present a simple rule to design the parameters of the AVQ algorithm. We then compare its performance through simulation with several wellknown AQM schemes such as RED, REM, PI controller and a nonadaptive virtual queue algorithm. With a view towards implementation, we show that AVQ can be implemented as a simple token bucket using only a few lines of code. 1
Statistical bandwidth sharing: a study of congestion at flow level
, 2001
"... In this paper we study the statistics of the realized throughput of elastic document transfers, accounting for the way network bandwidth is shared dynamically between the randomly varying number of concurrent flows. We first discuss the way TCP realizes statistical bandwidth sharing, illustrating es ..."
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Cited by 174 (17 self)
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In this paper we study the statistics of the realized throughput of elastic document transfers, accounting for the way network bandwidth is shared dynamically between the randomly varying number of concurrent flows. We first discuss the way TCP realizes statistical bandwidth sharing, illustrating essential properties by means of packet level simulations. Mathematical flow level models based on the theory of stochastic networks are then proposed to explain the observed behavior. A notable result is that first order performance (e.g., mean throughput) is insensitive with respect both to the flow size distribution and the flow arrival process, as long as “sessions ” arrive according to a Poisson process. Perceived performance is shown to depend most significantly on whether demand at flow level is less than or greater than available capacity. The models provide a key to understanding the effectiveness of techniques for congestion management and service differentiation. 1.
Bandwidth Sharing and Admission Control for Elastic Traffic
 Telecommunication Systems
, 1998
"... We consider the performance of a network like the Internet handling socalled elastic traffic where the rate of flows adjusts to fill available bandwidth. Realized throughput depends both on the way bandwidth is shared and on the random nature of traffic. We assume traffic consists of point to point ..."
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Cited by 160 (15 self)
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We consider the performance of a network like the Internet handling socalled elastic traffic where the rate of flows adjusts to fill available bandwidth. Realized throughput depends both on the way bandwidth is shared and on the random nature of traffic. We assume traffic consists of point to point transfers of individual documents of finite size arriving according to a Poisson process. Notable results are that weighted sharing has limited impact on perceived quality of service and that discrimination in favour of short documents leads to considerably better performance than fair sharing. In a linear network, maxmin fairness is preferable to proportional fairness under random traffic while the converse is true under the assumption of a static configuration of persistent flows. Admission control is advocated as a necessary means to maintain goodput in case of traffic overload. 1 Introduction Traffic in a multiservice network is essentially composed of individual transactions or flows...
Impact of Fairness on Internet Performance
 IN PROCEEDINGS OF ACM SIGMETRICS
, 2000
"... We discuss the relevance of fairness as a design objective for congestion control mechanisms in the Internet. Specifically, we consider a backbone network shared by a dynamic number of shortlived flows, and study the impact of bandwidth sharing on network performance. In particular, we prove that f ..."
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Cited by 156 (11 self)
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We discuss the relevance of fairness as a design objective for congestion control mechanisms in the Internet. Specifically, we consider a backbone network shared by a dynamic number of shortlived flows, and study the impact of bandwidth sharing on network performance. In particular, we prove that for a broad class of fair bandwidth allocations, the total number of ows in progress remains finite if the load of every link is less than one. We also show that provided the bandwidth allocation is "sufficiently" fair, performance is optimal in the sense that the throughput of the ows is mainly determined by their access rate. Neither property is guaranteed with unfair bandwidth allocations, when priority is given to one class of ow with respect to another. This suggests current proposals for a differentiated services Internet may lead to suboptimal utilization of network resources.
Scheduling Distributed Applications: The SimGrid Simulation Framework
 In Proceedings of the Third IEEE International Symposium on Cluster Computing and the Grid (CCGrid’03
, 2003
"... Abstract — Since the advent of distributed computer systems an active field of research has been the investigation of scheduling strategies for parallel applications. The common approach is to employ scheduling heuristics that approximate an optimal schedule. Unfortunately, it is often impossible to ..."
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Cited by 112 (29 self)
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Abstract — Since the advent of distributed computer systems an active field of research has been the investigation of scheduling strategies for parallel applications. The common approach is to employ scheduling heuristics that approximate an optimal schedule. Unfortunately, it is often impossible to obtain analytical results to compare the efficacy of these heuristics. One possibility is to conducts large numbers of backtoback experiments on real platforms. While this is possible on tightlycoupled platforms, it is infeasible on modern distributed platforms (i.e. Grids) as it is laborintensive and does not enable repeatable results. The solution is to resort to simulations. Simulations not only enables repeatable results but also make it possible to explore wide ranges of platform and application scenarios. In this paper we present the SimGrid framework which enables the simulation of distributed applications in distributed computing environments for the specific purpose of developing and evaluating scheduling algorithms. This paper focuses on SimGrid v2, which greatly improves on the first version of the software with more realistic networkmodels and topologies. SimGrid v2 also enables the simulation of distributed scheduling agents, which has become critical for current scheduling research in largescale platforms. After describing and validating these features, we present a case study by which we demonstrate the usefulness of SimGrid for conducting scheduling research. I.
Enabling Largescale Wireless Broadband: The Case for TAPs
, 2003
"... The vision is tantalizing: a highperformance, scalable, and widely deployed wireless Internet that facilitates services ranging from radically new and unforeseen applications to true wireless "broadband" to residences and public spaces at rates of 10s of Mb/sec. However, while highspeed wireless a ..."
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Cited by 98 (12 self)
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The vision is tantalizing: a highperformance, scalable, and widely deployed wireless Internet that facilitates services ranging from radically new and unforeseen applications to true wireless "broadband" to residences and public spaces at rates of 10s of Mb/sec. However, while highspeed wireless access is easy to achieve in an enterprise network via lowcost IEEE 802.11 (WiFi) access points, wireless technology in public spaces is in its infancy. "Hot spots" provide highspeed wireless access, but do so in very few isolated "islands" at immense costs. Likewise, while fixed wireless (e.g. LMDS) and 3G can provide ubiquitous coverage and 3G can support mobility, throughputs can often be two orders of magnitude slower than WiFi.
Stability of Distributed Congestion Control With Heterogeneous Feedback Delays
 IEEE Transactions on Automatic Control
, 2000
"... In this note we investigate how congestion control can achieve efficient usage of network resources in the presence of heterogeneous communication delays between network users and resources. To this end, we consider a fluid flow model of network behaviour. We study the stability of the system's beha ..."
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Cited by 91 (0 self)
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In this note we investigate how congestion control can achieve efficient usage of network resources in the presence of heterogeneous communication delays between network users and resources. To this end, we consider a fluid flow model of network behaviour. We study the stability of the system's behaviour under small perturbations around the target equilibrium point (local stability). We establish several criteria for stability of certain linear delaydifferential equations, via a technique which essentially reduces the question to studying stability of ordinary differential equations. These results are then used to derive sufficient conditions for local stability of the network congestion control problem. The same issue has been studied in [13], where the authors propose a conjecture according to which local stability can be ensured in a distributed way. The correctness of the conjecture is established in [13] only in degenerate cases where feedback delays coincide. Our results show that a relaxed form of the conjecture holds true for arbitrary feedback delays. 1