Resumen
The role of Software Defined Networking (SDN) and Network Function Virtualization (NFV) have been instrumental in realizing the transition and vision ?from black boxes to a white box towards facilitating 5G network architectures?. Though significant research results and several deployments have occurred and realized over the last few years focusing on the NFV and SDN technologies, several issues?both of theoretical and practical importance?remain still open. Accordingly, the papers of this special issue are significant contributions samples within the general ecosystem highlighted above, ranging from SDN and NFV architectures and implementations, to SDN-NFV integration and orchestration approaches, while considering issues associated with optimization, network management and security aspects. In particular, a total of nine excellent articles (one review and eight original research articles) have been accepted, following a rigorous review process, and addressing many of the aforementioned challenges and beyond.