2,465 research outputs found

    DiffServ resource management in IP-based radio access networks

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    The increasing popularity of the Internet, the flexibility of IP, and the wide deployment of IP technologies, as well as the growth of mobile communications have driven the development of IP-based solutions for wireless networking. The introduction of IP-based transport in Radio Access Networks (RANs) is one of these networking solutions. When compared to traditional IP networks, an IP-based RAN has specific characteristics, due to which, for satisfactory transport functionality, it imposes strict requirements on resource management schemes. In this paper we present the Resource Management in DiffServ (RMD) framework, which extends the DiffServ architecture with new admission control and resource reservation concepts, such that the resource management requirements of an IP-based RAN are met. This framework aims at simplicity, low-cost, and easy implementation, along with good scaling properties. The RMD framework defines two architectural concepts: the Per Hop Reservation (PHR) and the Per Domain Reservation (PDR). As part of the RMD framework a new protocol, the RMD On DemAnd (RODA) Per Hop Reservation (PHR) protocol will be introduced. A key characteristic of the RODA PHR is that it maintains only a single reservation state per PHB in the interior routers of a DiffServ domain, regardless of the number of flows passing through

    REDO RSVP: Efficient Signalling for Multimedia in the Internet

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    Alarming reports of performance and scalability problems associated with per-flow reservations, have led many to lose belief in RSVP and the Integrated Services Architecture that relies on it. Because we are convinced of the need for some form of resource reservation, to support multimedia communications in the Internet, we have set about trying to improve RSVP. By careful study of the protocol, we have identified areas for improvement, and propose REDO RSVP, a reduced overhead version that includes a fast establishment mechanism (FEM). In this paper we describe the rationale for REDO RSVP and present a detailed analysis of its features and operations. We also analyse REDO RSVP by means of simulations, and show that it offers improvements to the performance of RSVP

    Towards a choreography for IRS-III

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    In this paper we describe our ongoing work in developing a choreog-raphy for IRS-III. IRS-III is a framework and platform for developing WSMO based semantic web services. Our choreography framework is based on the KADS system-user co-operation model and distinguishes between the direction of messages within a conversation and which actor has the initiative. The im-plementation of the framework is based on message pattern handlers which are triggered whenever an incoming message satisfies pre-defined constraints. Our framework is explained through an extensive example

    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

    A scheme for time-dependent resource reservation in QoS-enabled IP networks

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    Abstract. A number of distributed applications require communication services with Quality of Service (QoS) guarantees. The QoS provisioning issue in the Internet has been addressed by the IETF with the definition of the Integrated Services (IntServ) and Differentiated Services (Diffserv) frameworks. Resource reservation mechanisms on which these models are based are totally time-unaware. Yet, we believe that, in some cases, associating a time interval to network resource reservations could be useful for both users and network providers. In this paper we present a distributed scheme for time-dependent reservations in QoS-enabled IP networks. We also show how the standard signalling protocol RSVP may support this new reservation style, with only a few minor modifications. Finally, we present a first prototype implementation of the major component of the proposed architecture and we provide some hints on future applicability scenarios of the advance reservation paradigm and its impact on related topics such as policing and charging techniques in QoS-enabled IP networks.
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