2,382 research outputs found

    The Dynamics of Internet Traffic: Self-Similarity, Self-Organization, and Complex Phenomena

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    The Internet is the most complex system ever created in human history. Therefore, its dynamics and traffic unsurprisingly take on a rich variety of complex dynamics, self-organization, and other phenomena that have been researched for years. This paper is a review of the complex dynamics of Internet traffic. Departing from normal treatises, we will take a view from both the network engineering and physics perspectives showing the strengths and weaknesses as well as insights of both. In addition, many less covered phenomena such as traffic oscillations, large-scale effects of worm traffic, and comparisons of the Internet and biological models will be covered.Comment: 63 pages, 7 figures, 7 tables, submitted to Advances in Complex System

    PABO: Mitigating Congestion via Packet Bounce in Data Center Networks

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    In today's data center, a diverse mix of throughput-sensitive long flows and delay-sensitive short flows are commonly presented in shallow-buffered switches. Long flows could potentially block the transmission of delay-sensitive short flows, leading to degraded performance. Congestion can also be caused by the synchronization of multiple TCP connections for short flows, as typically seen in the partition/aggregate traffic pattern. While multiple end-to-end transport-layer solutions have been proposed, none of them have tackled the real challenge: reliable transmission in the network. In this paper, we fill this gap by presenting PABO -- a novel link-layer design that can mitigate congestion by temporarily bouncing packets to upstream switches. PABO's design fulfills the following goals: i) providing per-flow based flow control on the link layer, ii) handling transient congestion without the intervention of end devices, and iii) gradually back propagating the congestion signal to the source when the network is not capable to handle the congestion.Experiment results show that PABO can provide prominent advantage of mitigating transient congestions and can achieve significant gain on end-to-end delay

    PRZECIĄŻENIE I ZARZĄDZANIE RUCHEM ŹRÓDEŁ WIADOMOŚCI O RÓŻNYCH PRIORYTETACH USŁUG

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    The scheme of dynamic management of traffic and activity of message sources with different priority of service is considered. The scheme is built on the basis of the neuroprognostic analysis model and the gradient descent method. For prediction and early detection of overload, the apparatus of the general theory of sensitivity with indirect feedback and control of activity of message sources is used. The control algorithm is started at the bottleneck of the network node. It uses a recursive prediction approach where the neural network output is referred to as many steps as defined by a given prediction horizon. Traffic with a higher priority is served without delay using the entire available bandwidth. Low-priority traffic will use the remaining bandwidth not used by higher-priority traffic. An algorithm for estimating the maximum available bandwidth of a communication node for traffic with a low service priority has been developed. This approach makes it possible to improve the efficiency of channel use without affecting the quality of service for high-priority traffic.Rozważono schemat dynamicznego zarządzania ruchem i aktywnością źródeł komunikatów o różnym priorytecie obsługi. Schemat zbudowany jest w oparciu o model analizy neuroprognostycznej oraz metodę gradientu. Do prognozowania i wczesnego wykrywania przeciążenia wykorzystuje się aparaturę ogólnej teorii wrażliwości z pośrednim sprzężeniem zwrotnym i kontrolą aktywności źródeł komunikatów. Algorytm sterowania jest uruchamiany w wąskim gardle węzła sieci. Wykorzystuje metodę predykcji rekurencyjnej, w której dane wyjściowe sieci neuronowej są odnoszone do tylu kroków, ile określono w danym horyzoncie predykcji. Ruch o wyższym priorytecie jest obsługiwany bez opóźnień z wykorzystaniem całej dostępnej przepustowości. Ruch o niskim priorytecie będzie wykorzystywał pozostałą przepustowość niewykorzystaną przez ruch o wyższym priorytecie. Opracowano algorytm szacowania maksymalnej dostępnej przepustowości węzła komunikacyjnego dla ruchu o niskim priorytecie usługi. Takie podejście umożliwia poprawę efektywności wykorzystania kanałów bez wpływu na jakość obsługi ruchu o wysokim priorytecie

    Reducing Internet Latency : A Survey of Techniques and their Merit

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    Bob Briscoe, Anna Brunstrom, Andreas Petlund, David Hayes, David Ros, Ing-Jyh Tsang, Stein Gjessing, Gorry Fairhurst, Carsten Griwodz, Michael WelzlPeer reviewedPreprin

    Diffusive capture processes for information search

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    We show how effectively the diffusive capture processes (DCP) on complex networks can be applied to information search in the networks. Numerical simulations show that our method generates only 2% of traffic compared with the most popular flooding-based query-packet-forwarding (FB) algorithm. We find that the average searching time, , of the our model is more scalable than another well known $n$-random walker model and comparable to the FB algorithm both on real Gnutella network and scale-free networks with $\gamma =2.4$. We also discuss the possible relationship between and , the second moment of the degree distribution of the networks

    Congestion bottleneck avoid routing in wireless sensor networks

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    A new efficient method for detecting congested bottleneck nodes and avoiding them in the route formation in a wireless sensor network is described. Sensor nodes with a higher degree of congestion are excluded while determining the best routing path from a given source to destination in a multi-hop transmission. In a scenario where different communication paths have different maximum congestion levels, selecting that path which has least maximum congestion, is a challenging task. A modified Bellman-Ford algorithm is proposed to solve this problem efficiently. The proposed technique is very much useful for the optimal route selection for vehicles in metropolitan cities that avoids high traffic density junctions. Once the desired destination is specified, the traffic control system can use this algorithm to provide the least congested routes to the intra-city vehicles
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