Domain-level-based routing algorithm in multidomain WDM optical network

We propose a domain-level-based routing (DLR) algorithm for a multidomain WDM network with confidentiality constraints of interdomain connectivity and wavelength availability. This algorithm classifies all domains in the network into different groups with incremental levels according to the metrics that they are relative to the source and destination domains. The path computation is implemented in the ascending or descending direction of domain levels for domains within the determined domain set. The resultant route is calculated via the growth and pruning of an interdomain routing tree (IDRT). Three modes of growth and five modes of pruning are proposed to support the IDRT evolution. The DLR algorithm can be accomplished in a hierarchical path computation element (PCE) routing architecture, with the domain set determined and the IDRT calculated by the parent PCE and intradomain path computed by child PCEs. Simulation results indicate that the proposed DLR algorithm performs better than previous schemes in terms of blocking probability and resource utilization ratio, with slight signaling overhead and computation complexity increase.