What is Cloud Network Function? Cloud Network Function is defined as a virtual network function (VNF), but with the added functionality of a VNF Manager and/or orchestration (MANO) that enable automated, elastic demand and service chaining functionality. Network functions virtualization (NFV) sometimes goes by VNF in the industry. Often used interchangeably, both focus primarily on optimization of the network services, contrary to software-defined networking (SDN), which separates the control and forwarding plane for a centralized view of the network. Virtual network function is designed to consolidate and deliver the networking components necessary to support a fully virtualized environment.