47 research outputs found

    XUNET experimental high-speed network testbed CRADA 1136, DOE TTI No. 92-MULT-020-B2

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    MDRS: a low complexity scheduler with deterministic performance guarantee for VBR video delivery.

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    by Lai Hin Lun.Thesis (M.Phil.)--Chinese University of Hong Kong, 2001.Includes bibliographical references (leaves 54-57).Abstracts in English and Chinese.Abstract --- p.iAcknowledgement --- p.ivTable of Contents --- p.vList of Figures --- p.viiChapter Chapter 1 --- Introduction --- p.1Chapter Chapter 2 --- Related Works --- p.8Chapter 2.1 --- Source Modeling --- p.9Chapter 2.2 --- CBR Scheduler for VBR Delivery --- p.11Chapter 2.3 --- Brute Force Scheduler: --- p.15Chapter 2.4 --- Temporal Smoothing Scheduler: --- p.16Chapter Chapter 3 --- Decreasing Rate Scheduling --- p.22Chapter 3.1 --- MDRS with Minimum Buffer Requirement --- p.25Chapter 3.2 --- 2-Rate MDRS --- p.31Chapter Chapter 4 --- Performance Evaluation --- p.33Chapter 4.1 --- Buffer Requirement --- p.35Chapter 4.2 --- Startup Delay --- p.38Chapter 4.3 --- Disk Utilization --- p.39Chapter 4.4 --- Complexity --- p.43Chapter Chapter 5 --- Conclusion --- p.49Appendix --- p.51Bibliography --- p.5

    Application of learning algorithms to traffic management in integrated services networks.

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    SIGLEAvailable from British Library Document Supply Centre-DSC:DXN027131 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

    A Study of Quality of Service Communication for High-Speed Packet-Switching Computer Sub-Networks

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    In this thesis, we analyze various factors that affect quality of service (QoS) communication in high-speed, packet-switching sub-networks. We hypothesize that sub-network-wide bandwidth reservation and guaranteed CPU processing power at endpoint systems for handling data traffic are indispensable to achieving hard end-to-end quality of service. Different bandwidth reservation strategies, traffic characterization schemes, and scheduling algorithms affect the network resources and CPU usage as well as the extent that QoS can be achieved. In order to analyze those factors, we design and implement a communication layer. Our experimental analysis supports our research hypothesis. The Resource ReSerVation Protocol (RSVP) is designed to realize resource reservation. Our analysis of RSVP shows that using RSVP solely is insufficient to provide hard end-to-end quality of service in a high-speed sub-network. Analysis of the IEEE 802.lp protocol also supports the research hypothesis

    Design of traffic shaper / scheduler for packet switches and DiffServ networks : algorithms and architectures

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    The convergence of communications, information, commerce and computing are creating a significant demand and opportunity for multimedia and multi-class communication services. In such environments, controlling the network behavior and guaranteeing the user\u27s quality of service is required. A flexible hierarchical sorting architecture which can function either as a traffic shaper or a scheduler according to the requirement of the traffic load is presented to meet the requirement. The core structure can be implemented as a hierarchical traffic shaper which can support a large number of connections with a wide variety of rates and burstiness without the loss of the granularity in cells\u27 conforming departure time. The hierarchical traffic shaper can implement the exact sorting scheme with a substantial reduced memory size by using two stages of timing queues, and with substantial reduction in complexity, without introducing any sorting inaccuracy. By setting a suitable threshold to the length of the departure queue and using a lookahead algorithm, the core structure can be converted to a hierarchical rateadaptive scheduler. Based on the traffic load, it can work as an exact sorting traffic shaper or a Generic Cell Rate Algorithm (GCRA) scheduler. Such a rate-adaptive scheduler can reduce the Cell Transfer Delay and the Maximum Memory Occupancy greatly while keeping the fairness in the bandwidth assignment which is the inherent characteristic of GCRA. By introducing a best-effort queue to accommodate besteffort traffic, the hierarchical sorting architecture can be changed to a near workconserving scheduler. It assigns remaining bandwidth to the best-effort traffic so that it improves the utilization, of the outlink while it guarantees the quality of service requirements of those services which require quality of service guarantees. The inherent flexibility of the hierarchical sorting architecture combined with intelligent algorithms determines its multiple functions. Its implementation not only can manage buffer and bandwidth resources effectively, but also does not require no more than off-the-shelf hardware technology. The correlation of the extra shaping delay and the rate of the connections is revealed, and an improved fair traffic shaping algorithm, Departure Event Driven plus Completing Service Time Resorting algorithm, is presented. The proposed algorithm introduces a resorting process into Departure Event Driven Traffic Shaping Algorithm to resolve the contention of multiple cells which are all eligible for transmission in the traffic shaper. By using the resorting process based on each connection\u27s rate, better fairness and flexibility in the bandwidth assignment for connections with wide range of rates can be given. A Dual Level Leaky Bucket Traffic Shaper(DLLBTS) architecture is proposed to be implemented at the edge nodes of Differentiated Services Networks in order to facilitate the quality of service management process. The proposed architecture can guarantee not only the class-based Service Level Agreement, but also the fair resource sharing among flows belonging to the same class. A simplified DLLBTS architecture is also given, which can achieve the goals of DLLBTS while maintain a very low implementation complexity so that it can be implemented with the current VLSI technology. In summary, the shaping and scheduling algorithms in the high speed packet switches and DiffServ networks are studied, and the intelligent implementation schemes are proposed for them

    Servidor de vídeo SVFSERVER

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    Orientador: Roberto A. HexselDissertação (mestrado)- Universidade Federal do Paraná. Setor de Ciencias Exatas. Programa de Pós-Graduação em InformáticaInclui bibliografi

    Satellite Networks: Architectures, Applications, and Technologies

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    Since global satellite networks are moving to the forefront in enhancing the national and global information infrastructures due to communication satellites' unique networking characteristics, a workshop was organized to assess the progress made to date and chart the future. This workshop provided the forum to assess the current state-of-the-art, identify key issues, and highlight the emerging trends in the next-generation architectures, data protocol development, communication interoperability, and applications. Presentations on overview, state-of-the-art in research, development, deployment and applications and future trends on satellite networks are assembled

    Fast techniques for the optimal smoothing of stored video

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