Experimental Validation of the ACTN architecture for flexi-grid optical networks using Active Stateful Hierarchical PCEs

The Abstraction and Control of Traffic Engineered Networks (ACTN) defines the requirements, use cases, and an SDN-based architecture, relying on the concepts of network and service abstraction, detaching the network and service control from the underlying data plane. The architecture encompasses Physical Network Controllers (PNCs), responsible for specific technology and administrative domains, orchestrated by Multi-Domain Service Coordinator (MDSC) which, in turn, enables underlay transport resources to be abstracted and virtual network instances to be allocated to customers and applications, under the control of a Customer Network Controller (CNC). In this paper, we present the application of the ACTN architecture to the control of a multi-domain flexi-grid optical network, by proposing, adopting and extending i) the Hierarchical active stateful Path Computation Element (PCE) architectures and protocols ii) the PCEP protocol to support efficient and incremental link state topological reporting, known as PCEP-LS (PCEP link state), iii) the per link partitioning of the optical spectrum based on variable-sized allocated frequency slots enabling network sharing and virtualization, and iv) the use of a model-based interface to dynamically request the instantiation of virtual networks for specific clients / tenants. We report the design and the implementation of the testbed in order to validate the approach.