YANG/NETCONF ROADM: Evolving Open DWDM Toward SDN Applications

Evolution in the field of optical networking in National Research and Education Networks led to utilization of Alien Wavelengths (AWs) and disaggregated Open Line Systems. Dynamic provisioning of AWs, in general spectrum services, is achieved via Reconfigurable Optical Add Drop Multiplexers (ROADMs) operating with flexible spectrum allocation. Northbound interface of these is usually implemented via the NETCONF protocol and through an appropriate Yet Another Next Generation (YANG) model. This paper presents a self-contained flexible spectral grid YANG model for low-level control and monitoring of a ROADM. The presented YANG model offers access to all functional components of a modern flexgrid ROADM and enables SDN applications to access and manipulate the media layer with no required external validation. The model is verified by an SDN application which implements optical path protection of AWs. A physical demonstration with model railroad intuitively shows the accomplished functionality.