881 research outputs found

    Capacity Requirements of Traffic Handling Schemes in Multi-Service Networks

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    Cataloged from PDF version of article.This paper deals with the impact of traffic handling mechanisms on capacity for different network architectures. Three traffic handling models are considered: per-flow, class-based and best-effort (BE). These models can be used to meet service guarantees, the major differences being in their complexity of implementations and in the quantity of network resources that must be provided. In this study, the performance is fixed and the required capacity determined for various combinations of traffic handling architectures for edge-core networks. This study provides a comparison of different QoS architectures. One key result of this work is that on the basis of capacity requirements, there is no significant difference between semi-aggregate traffic handling and per-flow traffic handling. However, best-effort handling requires significantly more capacity as compared to the other methods. (C) 2004 Elsevier B.V. All rights reserve

    A system architecture for low bit rate traffic aggregation in control applications

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    This paper describes the results of research work aimed at providing an efficient solution to the aggregation of low bit rate traffic in control applications. It includes the proposal and analysis of an architecture that integrates Terminal Adapters and a Concentrator connected to a remote Control Application through a communication network. The ATM technology was selected to implement the proposed system due to its properties of multiplexing efficiency and control of packet delay. Scheduling Algorithms for the Terminal Adapter and Concentrator have been developed in order to satisfy two main goals: to guarantee committed delays for time sensitive services, and to increase the network transmission efficiency. The results, obtained by simulation, show that the system performance complies with the requirements of the majority of control applications.Institute of Electrical and Electronics Engineers (IEEE)

    Operational and Performance Issues of a CBQ router

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    The use of scheduling mechanisms like Class Based Queueing (CBQ) is expected to play a key role in next generation multiservice IP networks. In this paper we attempt an experimental evaluation of ALTQ/CBQ demonstrating its sensitivity to a wide range of parameters and link layer driver design issues. We pay attention to several CBQ internal parameters that affect performance drastically and particularly to “borrowing”, a key feature for flexible and efficient link sharing. We are also investigating cases where the link sharing rules are violated, explaining and correcting these effects wheneverpossible. Finally we evaluateCBQ performance and make suggestions for effective deployment in real networks.

    Scheduling algorithms to support QoS and service integration in sensor and actuator networks

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    In this paper we analyse and evaluate several Scheduling Algorithms that are candidates to support Quality of Service and Service Integration in Sensor and Actuator Networks. They should satisfy two main goals: to guarantee committed delays for time sensitive services, and to improve the network transmission efficiency. The algorithms are described and some results, obtained by simulation, are presented. The proposed Traffic Class Oriented Algorithm proved to be a good solution to meet the proposed objectives as well as to integrate traffic generated by Fieldbus devices and control applications in real communication networks.IEE

    Project DIANA - Converging and Integrating IP and ATM for real-time applications

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    The evolution of IP and ATM share some common drivers. Both of them are addressing efficient network resource utilisation. In order to evaluate the options and combinations offered by these technologies the DIANA project is looking into the areas where ATM and IP both overlap and complete each other, that is QoS interworking between ATM and IP. This is achieved by investigating RSVP-over-ATM approach. This solution is compared with two IP level approaches: Differentiated Services and Scalable Resource Reservation Protocol (SRP)

    Comparison Data Traffic Scheduling Techniques for Classifying QoS over 5G Mobile Networks

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    Enhancing Quality of Service (QoS) in mobile networks is the key aim for mobile operators. Mobile networks transport several forms of data traffic for real-time applications (i.e., video monitoring). These applications need to get the advantage of QoS adaptation. Numerous scheduling techniques are utilized at the router to assure the QoS of the mobile networks. Upcoming 5G mobile networks will be launched; hence, Human-Type-Communication (HTC) and Machine-to-Machine (M2M) data traffic are expected to increase dramatically over mobile networks, which results in growing the capacity and raising high data rates. These networks are expected to face challenges in cases of Radio Access Network (RAN) overload and congestion due to the massive smart devices data traffic with various QoS requirements. This paper presents a comparison for data traffic scheduling techniques, which are Priority Queuing (PQ), First-In-First-Out (FIFO) and Weighted Fair Queuing (WFQ). We consider to select a suitable data traffic scheduling technique in terms of QoS provisioning and helping 5G network, also we propose models and algorithms for efficiently utilized the smallest unit of a RAN in a relay node by aggregating and slicing the data traffic of several M2M devices

    Theories and Models for Internet Quality of Service

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    We survey recent advances in theories and models for Internet Quality of Service (QoS). We start with the theory of network calculus, which lays the foundation for support of deterministic performance guarantees in networks, and illustrate its applications to integrated services, differentiated services, and streaming media playback delays. We also present mechanisms and architecture for scalable support of guaranteed services in the Internet, based on the concept of a stateless core. Methods for scalable control operations are also briefly discussed. We then turn our attention to statistical performance guarantees, and describe several new probabilistic results that can be used for a statistical dimensioning of differentiated services. Lastly, we review recent proposals and results in supporting performance guarantees in a best effort context. These include models for elastic throughput guarantees based on TCP performance modeling, techniques for some quality of service differentiation without access control, and methods that allow an application to control the performance it receives, in the absence of network support

    Advances in Internet Quality of Service

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    We describe recent advances in theories and architecture that support performance guarantees needed for quality of service networks. We start with deterministic computations and give applications to integrated services, differentiated services, and playback delays. We review the methods used for obtaining a scalable integrated services support, based on the concept of a stateless core. New probabilistic results that can be used for a statistical dimensioning of differentiated services are explained; some are based on classical queuing theory, while others capitalize on the deterministic results. Then we discuss performance guarantees in a best effort context; we review: methods to provide some quality of service in a pure best effort environment; methods to provide some quality of service differentiation without access control, and methods that allow an application to control the performance it receives, in the absence of network support

    Analysis of individual flows performance for delay sensitive applications

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    SLA management approaches typically adopt provisioning strategies based on aggregate traffic in order to support endtoend delay requirements of applications. They do not take into account individual flows needs in terms of delay. However, this delay can be very higher than the one observed by aggregate traffic, causing an important impact in network application performance. This paper presents a study based on simulations that makes an analysis of the endtoend delay observed by individual flows. Several scenarios are used to evaluate this performance and some metrics are proposed to investigate empirical relations that show the endtoend delay behavior when are analyzed individual flows, the aggregate traffic and the network load.5th IFIP International Conference on Network Control & Engineering for QoS, Security and MobilityRed de Universidades con Carreras en InformĂĄtica (RedUNCI

    Network level performance of differentiated services (diffserv) networks

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    The Differentiated Services (DiffServ) architecture is a promising means of providing Quality of Service (QoS) in Internet. In DiffServ networks, three service classes, or Per-hop Behaviors (PHBs), have been defined: Expedited Forwarding (EF), Assured Forwarding (AF) and Best Effort (BE). In this dissertation, the performance of DiffServ networks at the network level, such as end-to-end QoS, network stability, and fairness of bandwidth allocation over the entire network have been extensively investigated. It has been shown in literature that the end-to-end delay of EF traffic can go to infinity even in an over-provisioned network. In this dissertation, a simple scalable aggregate scheduling scheme, called Youngest Serve First (YSF) algorithm is proposed. YSF is not only able to guarantee finite end-to-end delay, but also to keep a low scheduling complexity. With respect to the Best Effort traffic, Random Exponential Marking (REM), an existing AQM scheme is studied under a new continuous time model, and its local stable condition is presented. Next, a novel virtual queue and rate based AQM scheme (VQR) is proposed, and its local stability condition has been presented. Then, a new AQM framework, Edge-based AQM (EAQM) is proposed. EAQM is easier to implement, and it achieves similar or better performance than traditional AQM schemes. With respect to the Assured Forwarding, a network-assist packet marking (NPM) scheme has been proposed. It has been demonstrated that NPM can fairly distribute bandwidth among AF aggregates based on their Committed Information Rates (CIRs) in both single and multiple bottleneck link networks
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