A Model-Driven Process Enactment Approach for Network Service Design

The development of the Network Functions Virtualisation (NFV) paradigm has made way for the rapid deployment and management of network services. The European Telecommunications Standards Institute (ETSI) has been actively defining the NFV framework, which includes functional blocks and artifacts at different levels of abstraction. As part of the artifacts, various deployment templates have been defined to drive the deployment and the management of network services (NS) and Virtual Networks Functions (VNFs). The design of an NS is a complex activity that aims at selecting appropriate VNFs, creating the VNF forwarding graph (VNFFG), and all the necessary templates for the NS deployment and management, on the basis of the tenant's requirements and existing VNFs. Automating the NS design activity as well as the NS management process itself is highly desirable and beneficial for NFV systems. Continuous deployment for NFV with model-driven orchestration means has been recently advocated. In this paper, we propose a model-driven process for the design of network services which covers the automatic generation of the NS deployment template and the associated templates. The core of the process involves the decomposition of the NS requirements with the help of an ontology, and the selection of proper network functions based on a catalogue of existing VNFs. Moreover, we provide support for automated process execution with a model-driven process enactment approach. The process is modelled as a UML activity diagram. All the artifacts are models of defined metamodels. Enactment of the NS design process is carried out by mapping the process model to a model transformation chain, and executing the chain.