A scalable architecture for end-to-end QoS provisioning

Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
Computer Communications 01/2004; DOI: 10.1016/j.comcom.2004.04.002
Source: DBLP

ABSTRACT The Differentiated Services (DiffServ) architecture has been proposed by the Internet Engineering Task Force as a scalable solution for providing end-to-end Quality of Service (QoS) guarantees over the Internet. While the scalability of the data plane emerges from the definition of only a small number of different service classes, the issue of a scalable control plane is still an open research problem. The initial proposal was to use a centralized agent, called Bandwidth Broker, to manage the resources within each DiffServ domain and make local admission control decisions. In this article, we propose an alternative decentralized approach, which increases significantly the scalability of both the data and control planes. We discuss in detail all the different aspects of the architecture, and indicate how to provide end-to-end QoS support for both unicast and multicast flows. Furthermore, we introduce a simple traffic engineering mechanism, which enables the more efficient utilization of the network resources.

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    IJCNS. 01/2009; 2:422-432.
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    ABSTRACT: Two important issues in assured services within differentiated services architecture are bandwidth guarantee and fair sharing of unsubscribed bandwidth among TCP flows with and without bandwidth reservations. Although the subscribed bandwidth can be guaranteed by increasing network capacity or deploying strict admission control mechanisms, the costs of such solutions are very high. The issue of fair sharing of excess bandwidth is also not well solved. To address those issues, a modified TCP, named two-windows TCP, has been proposed. The performance of the protocol is evaluated by simulations. But its effectiveness is not validated theoretically under general network conditions, which is important for understanding the benefits and costs of using the protocol. In this paper, an analytical model is developed for the purpose. The model characterizes throughput of individual two-windows TCP flow as a function of contract rate, round trip time, loss rates of In and Out packets. Extensive simulations validate the analytical model. It's shown two-windows TCP is effective not only on solving the issues of bandwidth guarantee and fair sharing of unsubscribed bandwidth, but also on increasing the utilization of bottleneck link bandwidth. Moreover, its performance is robust to network conditions, which is important for wide deployment over Internet.
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    ABSTRACT: A distributed and adaptive framework (DAF) was proposed for provisioning quality of service (QoS) in IPv6 network. In DAF, per-flow admission control and resource reservation, in conjunction with a new IPv6 flow label mechanism, can be performed instantaneously in a fully distributed and independent fashion at the edge of network without hop-by-hop signaling. The flow label helps in resource reservation and packets forwarding for aggregated traffic on an edge-to-edge path basis. In addition, a bounded directional probing technique for DAF was designed to reconfigure resource reservation adaptively between every pair of edge router for aggregated traffic according to the fluctuation of its traffic load. The simulation results show that DAF provides QoS guarantees to individual flows with minimal overhead, as well as keeping the scalability characteristic like DiffServ.
    Journal of Shanghai Jiaotong University (Science) 01/2008; 13(1):97-101.


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