The Virtual Topology Reconfiguration Controller for WDM Networks

Reconfiguration of WDM networks allows network operators to reconfigure the topologies in response to changing traffic demands to improve the QoS. To reconfigure the current virtual topology, the time to reconfigure is decided, and then a target topology is created. Next, real transition between topologies is occurred. We propose a VTR controller for WDM networks. First, our controller decides when current virtual topology is reconfigured. Some traffic may travel with single hop lightpaths and others may not. What the amount of traffic which is serviced through multi-hop increases shows that current virtual topology is not adequate for traffic demands. We use this information to reconfigure. And, the controller creates a target topology. As discontinuous wavelengths increases in networks, it can increase the difficulty of establishing single hop lightpaths for future traffic. Hence, the controller establishes the lightpaths which would remain discontinuous as few as possible after assigning.