Adaptive multilayer routing in the next generation GMPLS Internet

The Automatically Switched Optical Networks (ASONs) and the Generalized Multi Protocol Label Switching (GMPLS) control plane are envisaged to play an important role in the next generation Internet. They provide optical networks with intelligence and automation and they enable the Multilayer Traffic Engineering (MTE) paradigm which facilitates the IP/optical adaptive integrated routing. This paper proposes an adaptive strategy for integrated routing. The routing decision is based on the network state. The strategy either sets up a new lightpath or grooms traffic on the existing virtual topology depending on the resource utilization level experienced on the IP and optical layers. To reduce the quantity of control information, we also propose and evaluate a heuristic that overcomes scalability problems at the expenses of less optimal performance. The proposed strategies are evaluated by means of simulation and they are compared with two non adaptive routing policies widely investigated in literature.