<title>Multilevel QoS-policy-based routing management architecture appropriate for heterogeneous network environments</title>

Abstract

As telecom providers introduce new and more sophisticated services the necessity of a global, unified view of the network infrastructure becomes demanding. Today, heterogeneous backbone networks are interconnected in order to provide global connectivity. Due to technological impairments the cost of network operation, the maintenance complexity and the overuse of resources are extremely high under the goal of supporting the diverting customer requirements. We propose a scheme for ATM QoS support in such heterogeneous, multi-domain, multi-technology network environment. The objective is to optimise users' and networks' profits by giving them the opportunity to satisfy their requirements. Our approach introduces a manager able to take routing decisions supporting quality of service guarantees for the customers, while making efficient use of network resources. II'4TRODUCTIONIn today's telecommunications world the networks used for data, telephone, video-conferencing and other services are still based on different technologies. These networks run in part or whole over the same infrastructure and use discrete management systems that do not currently collaborate. This implies extremely high costs and complexity in use and management that resulted in increasing efforts to integrate all telecommunications services into one network, optimising resource allocation. The biggest challenge of this integration is the support of the different quality of service requirements of legacy services. Furthermore new compound services that start to appear, i.e., multiparty collaborative working sessions, have to be provided with the required total QoS in attractive prices, in order to create demand and subsequently increase optimised network usage. The heterogeneity of the telecommunication equipment together with the plethora of the organisations involved in service provision adds to the complexity ofthe problem.In order for a network to guarantee customers' QoS requirements, it should be able to reserve resources and excise network control functionality at different time-scales. In connection-oriented networks, the transfer of information between two endusers is accomplished by network functions that select and allocate network resources along an acceptable path. Routing is a call-level network control mechanism through which a path is derived for establishing communication between a source and a destination in a network. In this paper we propose a QoS-Policy based routing management architecture appropriate for heterogeneous, multi-domain, multi-technology networks.Several architectures have been proposed in the literature [3b0] for QoS guarantees of multimedia applications over ATM networks. ATM technology that plays a central role in the integration challenge, highly relies on the statistical multiplexing discipline. The conditions under which statistical multiplexing can work efficiently in an ATM network are an active area of research and experimentation in both academia and industry [5, 6] Several research organisations and sta...