A scaleable VP restoration system for reliable Internet configuration

Abstract

Since routers in IP network are connected with ATM Virtual Path (VP) Permanent Virtual Connection (PVC) and each V P contains bundles of VCs, a V P layer network can serve as a server layer and each IP'layer network can be a client layer. Therefore the effective Internet service provisioning completely depends on the reliability of V P server layer network from the perspective of the optimality and the network survivability. This paper proposes the distributed ATM V P PVC restoration framework with the dynamic rerouting schemes in hierarchical transport network. The rerouting algorithm aims to provide rapid ATM V P PVC restoration in the caSe of fault or performance degradation in terms of maximization of network resource utilization and satisfaction of the end user's Q o S requirement. It guarantees the IP network survivability in spite of ATM network faults or performance degradations. In addition, this paper evaluates the rerouting performance for a real network, the High Speed Information Network (HSIN). I. INTRODUCTIONAn important concept in ATM networks is the introduction of virtual path. A virtual path is a logical connection for nodes such as ATM switch, ATM V P Cross-Connect, and router. Each V P contains bundles of virtual channels that are routed together as a unit. There are a number of advantages of using the VP concept [2], [ 5 ] . For example, it can reduce call set-up delay, simplify the node and network structure, and segregate different types of traffic with different quality of service (QoS) requirement. It can also reduce processing lime for routing and bandwidth control burden in a node [Y]. On the other hand, network scalability and survivability are major issues the telecommunications industry eager to deploy large-scale ATM network. The scalability is designed with the aim of providing the capabilities of easy network expansion, coping with the dynamically changing network environment and the maximization of network manageability. The survivability is aimed at providing reliable and QoS guaranteed telecommunications services in spite of the network abnormalities and performance degradation.Hierarchical network deployment is one of the popular approaches for providing the network scalability, such as PNNI [9] and OSPF [lo]. It is based on network topology abstraction and decomposition of large-scale networks from the perspective of the management domain. ITU-T G.805 also defines the generic transport network architecture in terms of layering and partitioning [4]. The layering concept can be used to describe the relationship between I P and ATM V P in terms of the client/server layer relationship.Since each router is connected with ATM VP PVC, a V P 0-7803-7108-9/01/$10.00 (C)2001 IEEE 2006 0-7803 -7 108 -9/O