Network Service Overview
A network service is a final product offered to end users with a full description of its functionality and specified performance.
Administrative users deploy network services between two locations in a virtual network, so that traffic traveling in a specific direction on that link is subject to action from that service. The term network service is defined in the ETSI Network Functions Virtualization (NFV) standard.
A network service consists of a service chain of one or more linked network functions, which are provided by specific virtualized network functions (VNFs), with a defined direction for traffic flow and defined ingress and egress points. The term service chain refers to the structure of a network service, and although not defined in the ETSI NFV standard, this term is regularly used in NFV and software-defined networking (SDN).