Experimental Validation of the ACTN architecture for flexi-grid optical networks using Active Stateful Hierarchical PCEs Ramon Casellas, Ricard Vilalta, Ricardo Martínez, Raül Muñoz, Haomian Zheng +, Young Lee * Centre Tecnològic de Telecomunicacions de Catalunya (CTTC/CERCA), Castelldefels, Spain + Huawei Technologies Co., Ltd. Shenzhen, P.R.China * Huawei Technologies, Plano, TX, USA e-mail: ramon.casellas@cttc.es ABSTRACT 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. 1. INTRODUCTION AND MOTIVATION As transport networks evolve, the need to provide network abstraction and virtualization in a multi-domain setting has emerged as a key requirement for operators. Network virtualization refers to allowing customers and applications (tenants) to utilize and independently control allocated virtual network resources as if resources were real, thus supporting multitenancy. The network is “sliced”, with tenants being given a different partial and abstracted topology view of the physical underlying network. 2. ABSTRACTION AND CONTROL OF TRAFFIC ENGINEERED NETWOKS ARCHITECTURE The ACTN [1][2] Software Defined Network (SDN) architecture (Fig. 1), initially intended for optical transport and extended to other TE technologies, specifies the functional entities and methods for the coordination of resources across multiple domains, to provide end-to-end services. It comprises of Physical Network Controllers (PNCs), responsible for specific technology and administrative domains, connected to a Multi-Domain Service Coordinator (MDSC). The MDSC facilitates underlay transport resources to be abstracted and virtual network instances to be allocated, while a corresponding Customer Network Controller (CNC) manages virtual network instances. ACTN facilitates heterogeneous domain transport networking and control/management, while enabling a logically centralized multidomain orchestration, using a hierarchical architecture to scale. ROADM GMPLS Controller CCI ROADM CCI PCC PCC OSPF-TE RSVP-TE MDSC MD TED MD LSPDB Provisioning Underlying physical network infrastructure – Data & Control Plane (Domain 1) Topology Management PCEP Network Hypervisor Abstraction and Virtualization Tenant Control of Allocated slices CNC (Tenant 1) Management & Orchestration Tenant / SLice Allocation REST API Virtualization and abstraction Tenant / Slice Manager Applications Applications Client/ Tenant Applications CNC / SC (Tenant 2) Applications Applications Client/ Tenant Applications Topology Monitoring REST API Stackable CNC-2.1 CNC-2.2 PCEP Active Stateful Capabilities for provisioning and Link State for Topology abstraction and management TED LSPDB Provisioning Topology Management Virtualization and abstraction PNC MDSC TED LSPDB Provisioning Topology Management Virtualization and abstraction PNC Underlying physical network infrastructure – Data & Control Plane (Domain 2) GMPLS Controller ROADM GMPLS Controller CCI ROADM CCI PCC PCC OSPF-TE RSVP-TE GMPLS Controller Figure 1. Implemented ACTN with AS-PCE as CNC, MDSC and PNC over a GMPLS flexi-grid network.