Gartner defines the network service global market as the delivery of fixed corporate networking services with worldwide coverage. Services that this market evaluates include established global network services and emerging global network service categories, as follows: WAN services, predominantly managed hybrid WANs, cloud connectivity, Session Initiation Protocol (SIP) trunking, managed software-defined WAN (SD-WAN) services, network on-demand services, NFV services and vCPE.