Metro-Haul: SDN Control and Orchestration of Disaggregated Optical Networks with Model-Driven Development

SDN solutions for optical transport networks are often associated to single-vendor optical domains, managed as single entities, in a deployment model that is commonly referred to as fully aggregated. Such controllers do export and expose interfaces for the limited control of abstracted resources and operations via north-bound interface (NBI) to operations/business support systems (OSS/BSS), but such APIs are often vendor specific and internal control aspects related to provisioning, monitoring and resource management remain proprietary and not disclosed.Disaggregation of optical networks refers to a deployment model of optical systems, by composing and assembling open, available components, devices and sub-systems. This disaggregation is driven by multiple factor (the mismatch between the needs of operators and the ability to deliver adapted solutions by vendors or the increase in hardware commoditization) and disaggregated networks are an excellent use case for open and standard interfaces, showing the benefits of a unified, model-driven development.In this paper, we address the SDN control of a disaggregated optical networks and its role in a wider Control Management and Orchestration (COM) architecture to offer ETSI NFV Network Services in a metropolitan infrastructure, characterized by multiple geographical locations and NFVI. We highlight the main use cases and the implemented extensions to the ONOS Platform for the aforementioned purpose. We detail the design of the controller (core systems and applications); the approach taken for model driven-development, including the YANG modelling language for the different optical devices and the NETCONF protocol to remotely configure the devices and, finally, the experimental validation of the approach and implementation with selected scenarios.