Dynamic Overlay Multicasting for Deadline-Driven Requests Provisioning in Elastic Optical Networks

Due to recent developments in cloud computing and constantly increasing demand for high bitrate content, both overlay networks and multicasting providing new data-sensitive applications and services have been gaining more and more attention in the last years. In this paper, we assume that the overlay network is deployed to provide multicasting of so-called Deadline-Driven Requests (DDRs), that require to transmit given amount of data (e.g. tens of Gigabytes) before data-transfer deadline is up. As long as this requirement is fulfilled, we can flexibly select bandwidth in order to transmit given demand. We consider a multilayer optimization problem that combines two approaches - optimization of an overlay (application) dynamic multicasting sessions and next provisioning of created overlay multicasting trees as a sets of unicast demands in the underlying Elastic Optical Network (EON). We perform numerical experiments to compare different routing algorithms (cost metrics) for both overlay and optical layers. The obtained results show that proper selection of a routing algorithm has a significant impact on the network performance in terms of the blocking probability. Moreover, we show that our approach to overlay multicasting brings significant resources savings in comparison to using unicast transmission in the optical layer.