590 research outputs found

    QUALITY OF SERVICE ARCHITECTURES APPLICABILITY IN AN INTRANET NETWORK

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    The quality of service (QoS) concept, which appeared initially as a necessity to improve Internet users perception, deals actually with new valences along with information society maturation. At the organisation’s level, the Intranet network shall assure in a similar manner as the Internet all kinds of services, which are useful to the organisation’s users. Starting from the traditional QoS architectural models, network administrators shall plan and design a QoS architecture, which will map on the organisation’s requirements, having at disposal not only own network elements but also communication services provided by other operators. The aim of this paper is to present, starting from the general QoS models, a comparative study of main advantages and drawbacks in implementing a specific Intranet QoS architecture taking into consideration all kind of aspects (material, financial, human resources), which impact on a good Intranet QoS management.QoS, IntServ, DiffServ, IntServ over DiffServ, VPN-MPLS, Intranet network

    Dynamic bandwidth allocation in multi-class IP networks using utility functions.

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    PhDAbstact not availableFujitsu Telecommunications Europe Lt

    Quality of Service over Specific Link Layers: state of the art report

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    The Integrated Services concept is proposed as an enhancement to the current Internet architecture, to provide a better Quality of Service (QoS) than that provided by the traditional Best-Effort service. The features of the Integrated Services are explained in this report. To support Integrated Services, certain requirements are posed on the underlying link layer. These requirements are studied by the Integrated Services over Specific Link Layers (ISSLL) IETF working group. The status of this ongoing research is reported in this document. To be more specific, the solutions to provide Integrated Services over ATM, IEEE 802 LAN technologies and low-bitrate links are evaluated in detail. The ISSLL working group has not yet studied the requirements, that are posed on the underlying link layer, when this link layer is wireless. Therefore, this state of the art report is extended with an identification of the requirements that are posed on the underlying wireless link, to provide differentiated Quality of Service

    Evaluating the Perfomance of the Modified Dynamic Hose Model for Virtual Private Networks

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    This paper is designed to model a Modified Dynamic Hose Algorithm for data traffic management. The Virtual Private Network (VPN) under study was characterized and the data for transmission was modeled. Then Algorithm for Modified Dynamic Hose Model to handle varying traffic rates was developed and simulated using MATLAB. The results obtained from network characterization shows that variation in window size and packet size affects the throughput in a VPN as an increase in window size from 50kb to 100kb improved the throughput generated from 15 for the Conventional Hose Model to 28.3 for the Modified Dynamic Hose Model resulting in 13.3 throughputs, which translate to 47% improvement. Also variation in window size and packet size affects the throughput in a VPN as an increase in window size from 10kb to 50kb resulted to a maximum throughput of 3.01 for the Conventional Model as against 15 for the Modified Dynamic Hose Model resulting to additional 11.99 or improvement of 79.93%. The Modified Dynamic Hose Model algorithm, unlike the Conventional Hose Model, determines whether to drop a particular packet or to queue it thereby improving the bandwidth utilization, minimize latency (delays) and Virtual Private Network Throughput

    IP-based virtual private networks and proportional quality of service differentiation

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    IP-based virtual private networks (VPNs) have the potential of delivering cost-effective, secure, and private network-like services. Having surveyed current enabling techniques, an overall picture of IP VPN implementations is presented. In order to provision the equivalent quality of service (QoS) of legacy connection-oriented layer 2 VPNs (e.g., Frame Relay and ATM), IP VPNs have to overcome the intrinsically best effort characteristics of the Internet. Subsequently, a hierarchical QoS guarantee framework for IP VPNs is proposed, stitching together development progresses from recent research and engineering work. To differentiate IP VPN QoS, the proportional QoS differentiation model, whose QoS specification granularity compromises that of IntServ and Diffserv, emerges as a potential solution. The investigation of its claimed capability of providing the predictable and controllable QoS differentiation is then conducted. With respect to the loss rate differentiation, the packet shortage phenomenon shown in two classical proportional loss rate (PLR) dropping schemes is studied. On the pursuit of a feasible solution, the potential of compromising the system resource, that is, the buffer, is ruled out; instead, an enhanced debt-aware mechanism is suggested to relieve the negative effects of packet shortage. Simulation results show that debt-aware partially curbs the biased loss rate ratios, and improves the queueing delay performance as well. With respect to the delay differentiation, the dynamic behavior of the average delay difference between successive classes is first analyzed, aiming to gain insights of system dynamics. Then, two classical delay differentiation mechanisms, that is,proportional average delay (PAD) and waiting time priority (WTP), are simulated and discussed. Based on observations on their differentiation performances over both short and long time periods, a combined delay differentiation (CDD) scheme is introduced. Simulations are utilized to validate this method. Both loss and delay differentiations are based on a series of differentiation parameters. Though previous work on the selection of delay differentiation parameters has been presented, that of loss differentiation parameters mostly relied on network operators\u27 experience. A quantitative guideline, based on the principles of queueing and optimization, is then proposed to compute loss differentiation parameters. Aside from analysis, the new approach is substantiated by numerical results

    Topological Design of Multiple Virtual Private Networks UTILIZING SINK-TREE PATHS

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    With the deployment of MultiProtocol Label Switching (MPLS) over a core backbone networks, it is possible for a service provider to built Virtual Private Networks (VPNs) supporting various classes of services with QoS guarantees. Efficiently mapping the logical layout of multiple VPNs over a service provider network is a challenging traffic engineering problem. The use of sink-tree (multipoint-to-point) routing paths in a MPLS network makes the VPN design problem different from traditional design approaches where a full-mesh of point-to-point paths is often the choice. The clear benefits of using sink-tree paths are the reduction in the number of label switch paths and bandwidth savings due to larger granularities of bandwidth aggregation within the network. In this thesis, the design of multiple VPNs over a MPLS-like infrastructure network, using sink-tree routing, is formulated as a mixed integer programming problem to simultaneously find a set of VPN logical topologies and their dimensions to carry multi-service, multi-hour traffic from various customers. Such a problem formulation yields a NP-hard complexity. A heuristic path selection algorithm is proposed here to scale the VPN design problem by choosing a small-but-good candidate set of feasible sink-tree paths over which the optimal routes and capacity assignments are determined. The proposed heuristic has clearly shown to speed up the optimization process and the solution can be obtained within a reasonable time for a realistic-size network. Nevertheless, when a large number of VPNs are being layout simultaneously, a standard optimization approach has a limited scalability. Here, the heuristics termed the Minimum-Capacity Sink-Tree Assignment (MCSTA) algorithm proposed to approximate the optimal bandwidth and sink-tree route assignment for multiple VPNs within a polynomial computational time. Numerical results demonstrate the MCSTA algorithm yields a good solution within a small error and sometimes yields the exact solution. Lastly, the proposed VPN design models and solution algorithms are extended for multipoint traffic demand including multipoint-to-point and broadcasting connections

    A Survey on the Contributions of Software-Defined Networking to Traffic Engineering

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    Since the appearance of OpenFlow back in 2008, software-defined networking (SDN) has gained momentum. Although there are some discrepancies between the standards developing organizations working with SDN about what SDN is and how it is defined, they all outline traffic engineering (TE) as a key application. One of the most common objectives of TE is the congestion minimization, where techniques such as traffic splitting among multiple paths or advanced reservation systems are used. In such a scenario, this manuscript surveys the role of a comprehensive list of SDN protocols in TE solutions, in order to assess how these protocols can benefit TE. The SDN protocols have been categorized using the SDN architecture proposed by the open networking foundation, which differentiates among data-controller plane interfaces, application-controller plane interfaces, and management interfaces, in order to state how the interface type in which they operate influences TE. In addition, the impact of the SDN protocols on TE has been evaluated by comparing them with the path computation element (PCE)-based architecture. The PCE-based architecture has been selected to measure the impact of SDN on TE because it is the most novel TE architecture until the date, and because it already defines a set of metrics to measure the performance of TE solutions. We conclude that using the three types of interfaces simultaneously will result in more powerful and enhanced TE solutions, since they benefit TE in complementary ways.European Commission through the Horizon 2020 Research and Innovation Programme (GN4) under Grant 691567 Spanish Ministry of Economy and Competitiveness under the Secure Deployment of Services Over SDN and NFV-based Networks Project S&NSEC under Grant TEC2013-47960-C4-3-

    ARCFIRE : experimentation with the recursive InterNetwork Architecture

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    European funded research into the Recursive Inter-Network Architecture (RINA) started with IRATI, which developed an initial prototype implementation for OS/Linux. IRATI was quickly succeeded by the PRISTINE project, which developed different policies, each tailored to specific use cases. Both projects were development-driven, where most experimentation was limited to unit testing and smaller scale integration testing. In order to assess the viability of RINA as an alternative to current network technologies, larger scale experimental deployments are needed. The opportunity arose for a project that shifted focus from development towards experimentation, leveraging Europe's investment in Future Internet Research and Experimentation (FIRE+) infrastructures. The ARCFIRE project took this next step, developing a user-friendly framework for automating RINA experiments. This paper reports and discusses the implications of the experimental results achieved by the ARCFIRE project, using open source RINA implementations deployed on FIRE+ Testbeds. Experiments analyze the properties of RINA relevant to fast network recovery, network renumbering, Quality of Service, distributed mobility management, and network management. Results highlight RINA properties that can greatly simplify the deployment and management of real-world networks; hence, the next steps should be focused on addressing very specific use cases with complete network RINA-based networking solutions that can be transferred to the market

    Improving quality of service in the internet

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    The Internet transport technology was designed to be robust, resilient to link or node outages, and with no single point of failure. The resulting connectionless system supports what is called a "best effort datagram delivery service", the perfo rmance of which is often greatly unpredictable. To improve the predictability of IP-based networks, several Quality of Service technologies have been designed over the past decade. The first one, RSVP, based on reservation of resources, is operational but has several major deficiencies, such as scalability difficulties. However, associated to other more recent technologies -RSVP aggregation, Diffserv and MPLS- the combination may result into an appropriate solution for improving Quality of Service guarant ees in a scalable way. This article presents the state of the art on the field in an accurate, yet pedagogical style
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