Hierarchical and Recursive NFV Service Platform for End-to-End Network Service Orchestration Across Multiple NFVI Domains

The ETSI network function virtualisation (NFV) management and orchestration (MANO) architectural framework defines an NFV service platform composed of an NFV orchestrator and virtualised network function (VNFs) managers that are responsible to provide NFV network services. Network services can be defined as the joint instantiation of VNFs and the provisioning of required network connections between the different VNFs to jointly realise a more complex function (e.g. service function chaining). In general, it is assumed that a single service platform is governing the whole NFV infrastructure (NFVI) domain from the edge to the core of the network, composed of multiple edge computing and core DCs interconnected by heterogeneous optical access, metro and core transport networks. However, network operators will fragment their transport networks and DCs into multiple NFVI domains for scalability, administrative, or security issues. Each NFVI domain can be provided by different vendors relying on their own NFV service platforms or leveraging open source solutions such as SONATA, OSM, or ONAP. In this paper, we propose a hierarchical and recursive network service orchestration architecture to compose end-to-end network services by aggregating network services provided by per-domain NFV service platforms together with VNFs.