The role of SDN and NFV for flexible optical networks: Current status, challenges and opportunities

Today´s optical transport domains are typically built using fixed grid technology. They are statically configured and operationally intensive to manage, lacking the capability for dynamic services and elastic bandwidth. Recent research has established the benefits of flexible grid technologies for optical switching allowing dynamic and elastic management of the available bandwidth resources. Combined with Software Defined Networks (SDN) control principles and Network Functions Virtualization (NFV) infrastructure, we have the potential to fundamentally change the way we build, deploy and control network applications built on top of flexible optical networks. This paper outlines the current Internet Engineering Task Force (IETF) developments for standardizing flexible grid optical technologies, and discusses how software-defined and function virtualisation principles have and will continue to provide the key capabilities to further enable flexible optical switching technologies to control and deliver NFV-based services and applications. It addition it describes the benefits for the virtual Content Distribution Network (vCDN) use case when combined with an IETF´s SDN framework Application-Based Network Operations (ABNO). Finally, we highlight the research opportunities for furthering the application of SDN and NFV for control and orchestration of flexible optical networks using the IETF ABNO-based framework.