A hierarchical routing approach for optical transport networks

Although the automatically switched optical networks (ASON) specifications strongly recommend a hierarchical network architecture for these networks, this is still an open issue. The hierarchical network concept involves several mechanisms mainly related with signaling and routing, such as the aggregation scheme, the dissemination process, the updating policy and the routing algorithms. The existing mechanisms for flat networks must be substantially modified to be applied to a hierarchical network architecture. In this paper, authors propose a complete hierarchical routing approach mainly focusing on routing concerns, aiming to optimize the global network performance while guaranteeing scalability.