For buyers contracting authority
Choose 72720000 when the contract connects separate sites rather than wiring a single one. A nationwide link between ministries, a managed network joining a council's offices, or connectivity into a data centre all belong here. The boundary with Local area network services (72710000) is geographic, not technical: in-building cabling and switching is LAN, site-to-site reach is WAN.
Two neighbouring codes cause the real confusion. If what the authority buys is the raw transmission capacity, the leased lines or data circuits themselves, Telephone and data transmission services (64210000) often fits better, because that scope is carrier connectivity rather than a managed IT network. If the deal is mostly about running and supporting an existing network, look at Data network management and support services (72315000).
Where a single contract bundles circuits, equipment and management together, set the primary CPV code by the dominant deliverable. When the managed network is the point and the transmission lines are a means to it, 72720000 holds even with circuits in the package.