Survivable IP Topology Design with Re-Usage of BackupWavelength Capacity

In IP-over-WDM networks, wavelength circuits are often protected by dedicated backup circuits. Especially with future deployment of 100G transmission systems, there will be huge under-utilization of backup resources. Network utilization can be boosted by loaning the idle backup circuits to preemptible IP/packet services. In the event of a failure, IP traffic can be preempted and wavelength backup can be restored. To reroute the pre-empted IP traffic, the IP topology must remain connected. In this paper, we propose a novel approach for the design of survivable IP topology with re-use of backup wavelength capacity. We observe that borrowing idle backup capacity to preemptible IP traffic enables much higher resource utilization, allowing for relevant decrease of network cost, and that we can still ensure combined survivability of the IP and wavelength services by incurring in a very small additional cost.