Transparent virtual network embedding in elastic optical networks

Abstract

Network visualization in Elastic Optical Networks (EONs) utilizes the flexible spectral resources to map Virtual Networks (VN) requests onto the physical substrate network. The process of mapping the VN requests onto the physical substrate network is called Virtual Network Embedding (VNE) problem. The use of EONs in network virtualization brings in an additional requirement of satisfying the spectrum-continuity and sub-carrier consecutiveness constraints. In transparent VNE (t-VNE), all the virtual links from a VN request must be mapped to the substrate links with the same set of sub-carriers. This makes t-VNE even more challenging. In this paper, we propose a novel t-VNE algorithm called Alignment and Consecutiveness-aware Transparent Virtual Network Embedding (ACT-VNE), which takes into account the spectrum alignment and consecutiveness between adjacent fiber links when mapping virtual nodes onto the physical substrate nodes. We also introduce an extended scheme, namely, Importance, Alignment and Consecutiveness-aware Transparent Virtual Network Embedding (iACTs-VNE) that assigns virtual nodes to substrate nodes within close proximity to establish connections with less bandwidth utilization. Simulation results show that ACT-VNE and iACT-VNE yield a lower blocking probability than existing schemes. When comparing iACT-VNE with ACT-VNE, the former requires less average substrate path length and yields lower link utilization ratio but offers better blocking performance than the latter.