A heuristic approach for border node selection and traffic routing in multi-domain optical networks

In this article we present a heuristic for selecting a set of domain border nodes and an improved routing scheme to route intra- and inter-domain traffic with low blocking probability in multi-domain multi-rate optical networks. The selection of border nodes is based on topological parameters and on intra-domain traffic. The routing scheme is impairment- and bandwidth-aware and searches for the optimum lightpath through the domains that meets the connection requests based on an improved system of weights assigned to links. The traffic routing is based on the Backward-Recursive Path Computation Element (PCE)-based Computation (BRPC) procedure of the Internet Engineering Task Force (IETF), which means that domains inform only a set of shortest paths that are strictly essential to route the traffic. The network model fits the Automatically Switched Optical Network (ASON) architecture of the International Telecommunication Union (ITU-T) and the operational management of the network is based on the procedures of the IETF Generalized Multi-Protocol Label Switching (GMPLS) control plane. Numerical results from computational simulations show the versatility and usefulness of the proposed scheme, which improves the blocking probability of inter-domain traffic by up to 41.5% compared to a scheme reported in the literature.