Optical cost metrics in multi-layer traffic engineering for IP-over-optical networks

Automatic switched optical networks (ASONs) or intelligent optical networks (IONs) facilitate setting up or tearing down end-to-end lightpaths dynamically. For an IP-over-optical network scenario, multi-layer traffic engineering (MTE) allows this optical flexibility to be used to reconfigure the logical IP topology in order to cope with changing traffic demands. Utilising an overlay model limits the information exchange between both layers. However, we show that by incorporating even simple optical cost metrics in the MTE process, we can attain significant cost savings in the optical layer, compared to the case where no information (beyond reachability) is communicated - and this with minimal impact on IP layer performance.