RFC 9730: Interworking of GMPLS Control and Centralized Controller Systems

Generalized Multiprotocol Label Switching (GMPLS) control allows each network element (NE) to perform local resource discovery, routing, and signaling in a distributed manner. The advancement of software-defined transport networking technology enables a group of NEs to be managed through centralized controller hierarchies. This helps to tackle challenges arising from multiple domains, vendors, and technologies. An example of such a centralized architecture is the Abstraction and Control of Traffic-Engineered Networks (ACTN) controller hierarchy, as described in RFC 8453. Both the distributed and centralized control planes have their respective advantages and should complement each other in the system, rather than compete. This document outlines how the GMPLS distributed control plane can work together with a centralized controller system in a transport network.