Benefits of GMPLS for multilayer recovery

IP-based backbone networks are gradually moving towards a network model consisting of high-speed routers that are flexibly interconnected by lightpaths set up by an optical transport network consisting of WDM links and optical cross-connects. Recovery mechanisms at both network layers are crucial to reach the high availability requirements of critical services. In such a model, the GMPLS protocol suite can provide a distributed control plane that can be used to deliver rapid and dynamic circuit provisioning of end-to-end optical lightpaths. This article explains that it can be very beneficial to exploit this functionality to enhance the cost effectiveness of multilayer recovery significantly. Several practical case studies illustrate this concept and highlight the opportunities and challenges to be faced.