The present document objective is to identify the most common and relevant software architectural patterns present when virtualising network functions and therefore to identify and specify functional requirements necessary to enable such patterns. The information consolidated is reflecting the experience from vendors and operators going through virtualisation of a number of network functions, with a focus on the use case list provided by the NFV Use Cases GS document     ETSI GS NFV 001 (V1.1.1): "Network Functions Virtualisation (NFV); Use Cases”.
 
The present document describes the Network Function Virtualisation abstract software architecture comprising of the following topics:

• Defining the functions, and interfaces of software architecture relative to the NFV overall architecture.
• Supporting Management and Orchestration Functional requirements.
• Supporting Infrastructure requirements.
• Describing best practices for NFV Design.
• Functional Decomposition types and use cases.

The present document does not provide any detailed specification. However, the present document makes reference to specifications developed by other bodies, gap, and to potential specifications.