Transport Northbound Interface: The need for Specification and Standards coordination

Next generation optical transport networks have high benchmarks for flexibility, reliability, and operational simplicity. These requirements underline a common, technology-independent orchestration paradigm that can be extended to represent and configure specific optical technology attributes. Although, orchestration is an ongoing aspect of the current optical transport network evolution, the meaning and scope of orchestration is often only implied, and various Specification and Standards communities cannot always agree the requirements and objectives. This paper describes the high-level requirements facing optical transport networks to provide well-defined Transport Northbound Interface (T-NBI) for optical resource programmability, control, and management automation. It explores the overall functionality that must be provided, whether encompassed in a single large-scale orchestration wrapper or partitioned into several sub-functions, of which only one component is designated as a transport orchestrator. It highlights the early efforts for optical transport resource modeling across Specification and Standardisation organisations. The paper will report on recent Internet Engineering Task Force (IETF) Transport NBI Team Design Team efforts to collaborate across Standards Development Organisations (SDOs) to unify transport interface requirements and objectives. Finally, the paper will highlight use cases and applicability examples, and outline research gaps and challenges, opportunities for researchers, and areas for further collaboration between academia and industry.