Overview of South-Bound Interfaces for Software-Defined Optical Networks

In SDN-enabled networks, the control plane and data plane interaction relies on open SouthBound Interfaces (SBIs) so that the SDN controller exercises direct control over the data plane elements. In this paper, we review current initiatives of SBI to control optical components which include ad-hoc extensions of OpenFlow and YANG modelling proposals combined with the NETCONF / RESTCONF protocols. Then we overview different tools and frameworks available for quick prototyping and deployment of software services that are compliant with such interfaces. Finally, we discuss the advantages and drawbacks of the reviewed initiatives considered key enablers for standardized end-to-end network programmability.