Multi-ring approach for ATM-VP networks survivability

A multiring approach to the problem of a virtual path (VP) restoration in asynchronous transfer mode (ATM) networks is introduced. The flexible restoration architecture provided can survive simultaneous network equipment failures, like fiber cuts or node defects. Multilevel protection of VPs against failures is achieved as a result of planning on a central basis (preventive restoration action) combined with distributed control (reactive restoration action). The strategy provides several coherent schemes ranging from centralized to distributed processing. Each of them is a tradeoff between performance requirements and costs. The major schemes are presented and discussed. To illustrate the approach, an example mesh-type ATM-VP network is analyzed