Connectivity as a Service: Towards optical-based network virtualization

With the emerging of network virtualization, it is envisioned that optical networking should move towards a virtualized substrate to support the next-generation Internet. The virtualization of optical networking enables Connectivity as a Service (CaaS) to the upper layers by supplying virtualized any-to-any bandwidth-abundant connections. In this paper, we present a holistic view of the motivations, architecture, and challenges in network virtualization supported by a virtualized optical substrate. We investigate the integration of these two trends, and discuss the added dimension of complexity to the fundamental virtual network embedding (VNE) problem in network virtualization, by which the logical (or service) network and the physical (or substrate) network are bridged. In addition, we present a prototype optimization model for the VNE problem over wavelength-division multiplexing (WDM) networks, and highlight the open problems that deserve future study.