Virtual network function scheduling: Concept and challenges

Software-Defined Networking and Network Functions Virtualization have initiated a new landscape within the telecom market landscape. Initial proof-of-concept prototypes for NFV-enabled solutions are being developed at the same time SDN models are identified as the futures solutions within the telecom realm. In this article, we provide a brief overview of the application and state-of-the-art of SDN and NFV technologies over optical networks. At the same time, we provide the first formalisation model for the VNF complex scheduling problem, using the complex job formalisation. The article aims at being used as starting point in order to optimally solve the scheduling problem of virtual network functions that compose network services to be provisioned within the SDN paradigm. Finally, we also provide an example of the virtualization of the routing function over an SDN-enabled domain.