QoS Guaranteed Routing in Wide Area Networks

In this paper. we investigate the problem of management and control in wide area networks. Especially we focus on QoS guaranteed routing, the important function of network management. QoS guaranteed routing in a large network comes to be intractable because data management and routing computation usually becomes a formidable task. Moreover. in general. an wide area network consists of heterogeneous sub-domains. In this paper. we propose the hierarchical routing scheme that enables QoS routing between heterogeneous domains and reduces routing time even in a large network. The proposing routing scheme is the one using routing service of Network Control Center(NCC) and domain based routing approach so as to resolve the problems caused by resource information management in every node in previous studies. The network consists of several individually controlled domains, which are interconnected by gateway links. Each domain is controlled by its own NCC, and NCCs are organized hierarchically. Each NCC maintains routing information for its own intra-domain routing, and has a portion of the information required for inter-domain routing. To accomplish domain-level inter-domain routing, the information of more than one NCC is merged. Also, we present the way of mapping a complex multi-domain topology graph into a simplified graph and solving inter-domain routing problem seamless as intra-domain routing. The proposed hierarchical routing scheme makes it possible to manage large network, and makes routing problem simple by dividing the problem into small parts so that each pan solved easily.