1,366 research outputs found

    Ethernet - a survey on its fields of application

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    During the last decades, Ethernet progressively became the most widely used local area networking (LAN) technology. Apart from LAN installations, Ethernet became also attractive for many other fields of application, ranging from industry to avionics, telecommunication, and multimedia. The expanded application of this technology is mainly due to its significant assets like reduced cost, backward-compatibility, flexibility, and expandability. However, this new trend raises some problems concerning the services of the protocol and the requirements for each application. Therefore, specific adaptations prove essential to integrate this communication technology in each field of application. Our primary objective is to show how Ethernet has been enhanced to comply with the specific requirements of several application fields, particularly in transport, embedded and multimedia contexts. The paper first describes the common Ethernet LAN technology and highlights its main features. It reviews the most important specific Ethernet versions with respect to each application field’s requirements. Finally, we compare these different fields of application and we particularly focus on the fundamental concepts and the quality of service capabilities of each proposal

    Optical fibre local area networks

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    Impact of topology on layer 2 switched QoS sensitive services

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    High-bandwidth QoS sensitive services such as large scale video surveillance generally depend on provisioned capacity delivered by circuit-switched technology such as SONET/SDH. Yet development in layer 2 protocol sets and manageability extensions to Ethernet standards propose layer 2 packet switching technology as a viable, cheaper alternative to SONET/SDH. Layer 2 switched networks traditionally offer more complex topologies; in this paper we explain general QoS issues with layer 2 switching and show the impact of topology choice on service performance

    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

    Resource virtualisation of network routers

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    There is now considerable interest in applications that transport time-sensitive data across the best-effort Internet. We present a novel network router architecture, which has the potential to improve the Quality of Service guarantees provided to such flows. This router architecture makes use of virtual machine techniques, to assign an individual virtual routelet to each network flow requiring QoS guarantees. We describe a prototype of this virtual routelet architecture, and evaluate its effectiveness. Experimental results of the performance and flow partitioning of this prototype, compared with a standard software router, suggest promise in the virtual routelet architecture

    Regulatory Approaches to NGNs: An International Comparison

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    The emergence of Next Generation Networks (NGNs) raises profound challenges for regulators everywhere. Different regulatory authorities have approached these problems in strikingly different ways, depending in part on the overall regulatory milieu in which they operate, and in part on the nature of the NGN migration envisioned by major market players. Also, the NGN core network raises significantly different issues from those of the NGN access network. The migration to NGN raises many of the same issues that were already on the table as a result of the broader migration to IP-based services,notably in regard to the de-coupling of the service from the underlying network. To these concerns are added profound questions related to the nature of market power. Will NGNs enable new forms of competition? Will competitive bottlenecks remain, especially in the last mile? Will NGN enable new forms of bottlenecks to emerge, especially in the upper layers of the network, perhaps as a result of new IMS capabilities? Regulators in the UK, Netherlands, Germany, Japan and the United States have been forced to deal with these issues due to relatively rapid migration to NGNs proposed by their respective incumbent telecoms operators. Many of the same issues are also visible in the recommendations that the European Commission finalised on 13 November 2007 as part of the ongoing review of the European regulatory framework for electronic communications. In this paper, we compare and contrast the many regulatory proceedings that have been produced by these regulatory authorities.Regulation; Next Generation Networks; access network; core network; all-IP; competition; market power; international comparison.

    Regulatory Approaches to NGNs: An International Comparison

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    The emergence of Next Generation Networks (NGNs) raises profound challenges for regulators everywhere. Different regulatory authorities have approached these problems in strikingly different ways, depending in part on the overall regulatory milieu in which they operate, and in part on the nature of the NGN migration envisioned by major market players. Also, the NGN core network raises significantly different issues from those of the NGN access network. The migration to NGN raises many of the same issues that were already on the table as a result of the broader migration to IP-based services, notably in regard to the de-coupling of the service from the underlying network. To these concerns are added profound questions related to the nature of market power. Will NGNs enable new forms of competition? Will competitive bottlenecks remain, especially in the last mile? Will NGN enable new forms of bottlenecks to emerge, especially in the upper layers of the network, perhaps as a result of new IMS capabilities? Regulators in the UK, Netherlands, Germany, Japan and the United States have been forced to deal with these issues due to relatively rapid migration to NGNs proposed by their respective incumbent telecoms operators. Many of the same issues are also visible in the recommendations that the European Commission finalised on 13 November 2007 as part of the ongoing review of the European regulatory framework for electronic communications. In this paper, we compare and contrast the many regulatory proceedings that have been produced by these regulatory authorities.Regulation; Next Generation Networks; access network; core network; all-IP; competition; market power; international comparison

    Performance evaluation of AAL2 over IP in the UMTS access network Iub interface

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    Bibliography: leaves 84-86.In this study, we proposed to retain AAL2 and lay it over IP (AAL2IIP). The IP-based lub interface is therefore designed to tunnel AAL2 channels from the Node B to the RNC. Currently IP routes packets based on best-effort which does not guarantee QoS, To provide QoS, MPLS integrated with DiffServ is proposed to support different QoS levels to different classes of service and fast forward the IP packets within the lub interface. To evaluate the performance of AAL2!IP in the Iub interface, a test-bed was created

    Multicast traffic aggregation in MPLS-based VPN networks

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    This article gives an overview of the current practical approaches under study for a scalable implementation of multicast in layer 2 and 3 VPNs over an IP-MPLS multiservice network. These proposals are based on a well-known technique: the aggregation of traffic into shared trees to manage the forwarding state vs. bandwidth saving trade-off. This sort of traffic engineering mechanism requires methods to estimate the resources needed to set up a multicast shared tree for a set of VPNs. The methodology proposed in this article consists of studying the effect of aggregation obtained by random shared tree allocation on a reference model of a representative network scenario.Publicad
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