Search results for "Active queue management"

showing 9 items of 9 documents

AQM Stability in Multiple Bottleneck Networks

2004

In this paper, we highlight that multiple bottlenecks can affect the performance of active queue management controllers, which are usually configured on a single bottleneck basis, as if each controller were the only element regulating the TCP traffic along its path. To see this, we consider a network scenario where RED is configured at each router, according to previously developed control theoretic techniques. These configuration rules assure stability in a single bottleneck scenario. Yet, we show that instability may arise when two link become congested. We justify this result through a multiple bottleneck model and give guidelines for new cooperative AQM controllers.

RouterQueueing theorybusiness.industryComputer scienceDistributed computingPropagation delayActive queue managementBottleneckActive Queue Management bottlenecksIntelligent NetworkSettore ING-INF/04 - AutomaticaControl theoryPath (graph theory)Settore MAT/09 - Ricerca OperativabusinessComputer network
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An API for Advanced Traffic Control in Diffserv Routers

2003

Distributed per-flow admission control is a promising solution for Differentiated Services networks. Its deployment in DiffSery domains requires the ability to suitably configure, in each network router, low-level packet forwarding mechanisms, such as packet dropping algorithms driven by traffic measurements. In this paper we first show that performance effectiveness is achieved by means of non traditional configuration of the forwarding mechanisms. Hence, we propose a modular Application Program Interface that allows to flexibly and adaptively configure the forwarding/dropping behavior associated to a router’s output queue, well beyond the traditional RED/RIO active queue management scheme…

RouterEngineeringDifferentiated servicesbusiness.industryNetwork packetPacket forwardingRandom early detectionAdmission controlActive queue managementbusinessQueueComputer network
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Tuning of QoS Aware Load Balancing Algorithm (QoS–LB) for Highly Loaded Server Clusters

2001

This paper introduces a novel algorithm for content based switching. A content based scheduling algorithm (QoS Aware Load Balancing Algorithm, QoS-LB) which can be used at the front-end of the server cluster is presented. The front-end switch uses the content information of the requests and the load on the back servers to choose the server to handle each request. At the same time, different Quality of Service (QoS) classes of the customers can be considered as one parameter in the load balancing algorithm. This novel feature becomes more important when service providers begin to offer the same services for customers with different priorities.

Network Load Balancing ServicesComputer scienceQuality of serviceComputer clusterServerRound-robin DNSMobile QoSLoad balancing (computing)Service providerActive queue managementAlgorithmScheduling (computing)
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AQM generalized nyquist stability in multiple bottleneck networks

2005

Abstract The influence of multiple bottlenecks on the stability of Active Queue Management (AQM) controllers, usually configured on a single bottleneck basis is discussed. We consider a network scenario where RED is configured at each router according to previously developed control theoretic techniques. These configuration rules assure stability in a single bottleneck scenario. We show that instability may arise when two links become congested. We justify this result through a multiple bottleneck model using the Generalized Nyquist stability criterion.

RouterBasis (linear algebra)Communication networks; Control theory; Stability analysis;Control theoryNyquist stability criterionStability (learning theory)Active queue managementTelecommunications networkBottleneckMathematics
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A genetic algorithm for the design of a fuzzy controller for active queue management

2003

Active queue management (AQM) policies are those\ud policies of router queue management that allow for the detection of network congestion, the notification of such occurrences to the\ud hosts on the network borders, and the adoption of a suitable control\ud policy. This paper proposes the adoption of a fuzzy proportional\ud integral (FPI) controller as an active queue manager for Internet\ud routers. The analytical design of the proposed FPI controller is\ud carried out in analogy with a proportional integral (PI) controller,\ud which recently has been proposed for AQM. A genetic algorithm is\ud proposed for tuning of the FPI controller parameters with respect\ud to optimal disturbance rej…

Settore ING-INF/05 - Sistemi Di Elaborazione Delle InformazioniRouterQueue management systemComputer sciencePID controllerFuzzy control systemRandom early detectionTCP Congestion ControlActive queue managementNetwork CongestionFuzzy logicComputer Science ApplicationsHuman-Computer InteractionNetwork congestionControl and Systems EngineeringControl theoryElectrical and Electronic EngineeringTail dropActive Queue ManagementSoftwareFuzzy Controllers.Information SystemsIEEE Transactions on Systems, Man and Cybernetics, Part C (Applications and Reviews)
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About the stability of active queue management mechanisms

2004

In this paper, we discuss the influence of multiple bottlenecks on the stability of active queue management (AQM) controllers, usually configured on a single bottleneck basis. To see this, we consider a network scenario where RED is configured at each router according to previously developed control theoretic techniques. These configuration rules assure stability in a single bottleneck scenario. Yet, we show that instability may arise when two links become congested. We justify this result through a multiple bottleneck model.

RouterEngineeringQueueing theorybusiness.industryControl (management)Stability (learning theory)Active queue managementbusinessBottleneckComputer networkProceedings of the 2004 American Control Conference
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Active queue management stability in multiple bottleneck networks

2004

In this paper, we show that the active queue management (AQM) controllers, usually configured on a single bottleneck basis, may not prevent instability in the presence of multiple bottlenecks. We justify this result through a multiple bottleneck model.

Queueing theoryAQM algorithmQueue management systemComputer sciencebusiness.industryDistributed computingStability (learning theory)Active queue managementBottleneckNetwork traffic controlManagementNetwork congestionCongestion control (communication)businessComputer network managementComputer network
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An analytical model of a new packet marking algorithm for TCP flows

2005

In Differentiated Services networks, packets may receive a different treatment according to their Differentiateo Services Code Point (DSCP) label. As a consequence, packet marking schemes can also be devised to differentiate packets belonging to a same TCP flow, with the goal of improving the performance experienced. This paper presents an analytical model for an adaptive packet marking scheme proposed in our previous work. The model combines three specific sub-models aimed at describing (i) the TCP sources aggregate, (ii) the marker, and (iii) the network status. Preliminary simulation results show quite accurate predictions for throughput and average queue occupancy. Besides, the research…

TCP accelerationComputer Networks and CommunicationsComputer scienceTransmission Control ProtocolTCP tuningThroughputRandom early detectionRound-trip delay timeH-TCPActive queue managementTCP sequence prediction attackComputer securitycomputer.software_genrelaw.inventionTCP Westwood plusTCP Friendly Rate ControlPacket switchinglawInternet ProtocolZeta-TCPQueueNetwork packetbusiness.industryComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKSToken bucketTelecommunications networkTCP global synchronizationDifferentiated servicesNetwork servicebusinesscomputerComputer network
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Parallel Genetic Algorithms for the Tuning of a Fuzzy AQM Controller

2003

This paper presents the results of the application of a parallel Genetic Algorithm (GA) in order to design a Fuzzy Proportional Integral (FPI) controller for active queue management on Internet routers. The Active Queue Management (AQM) policies are those policies of router queue management that allow the detection of network congestion, the notification of such occurrences to the hosts on the network borders, and the adoption of a suitable control policy. Two different parallel implementations of the genetic algorithm are adopted to determine an optimal configuration of the FPI controller parameters. Finally, the results of several experiments carried out on a forty nodes cluster of workst…

RouterSettore ING-INF/05 - Sistemi Di Elaborazione Delle InformazioniQueue management systemComputer sciencebusiness.industryDistributed computingFuzzy control systemActive queue managementFuzzy logicNetwork congestionTCP Actuve Queue Management Genetic algorithms Fuzzy logic AQM TCP congestion controlControl theoryGenetic algorithmbusinessComputer network
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