Particle Swarm Optimization-Enhanced Virtual Multicast Trees Embedding in SDNs

The truly innovative network virtualization technology allows for multi-tenancy, enabling different Virtual Network (VN) requests to share the same physical network. This is achievable because network services are no longer bound to the architecture of the lessor hardware. Virtual Network Embedding (VNE) is a multi-dimensional NP-Hard problem that maps VN entities such as virtual nodes and virtual links onto a shared Substrate Network (SN) while assuring the requested network resources (e.g., bandwidth, computing power, etc.). This research explores how to efficiently map VNs with one-to-many (multicast) interactions, in the form of Virtual Multicast Trees (VMTs), onto an SN in contrast to the VNE problem where one-to-one (unicast) communication is at focus. Thus, we propose a Virtual Multicast Tree Embedding (VMTE) enhanced by Particle Swarm Optimization framework, VMTE-PSO, to put VMTs on a shared SN. The VMTE-PSO aims to minimize the amount of network resource consumption (i.e., bandwidth) in the SN while simultaneously satisfying the computing demand of virtual nodes and minimizing the redundant substrate link usage. Extensive simulations reveal our algorithm outperforms the dynamic node ranking and traditional greedy-based VMTE approaches with respect to bandwidth consumption and redundant multicast transmission on NSFNET and USNET network topologies.