Apparatus for guarding data communication systems against unauthorised access, namely, network routers, gateway routers in the nature of computer control hardware, VPN (virtual private network) hardware; apparatus for linking computers into networks, namely, computer network adapters, network routers, gateway routers in the nature of computer control hardware, VPN (virtual private network) hardware, LAN (local area network) hardware, computer hardware in the nature of wireless access point (WAP) devices, computer hardware in the nature of thin client access point devices, network routers in the nature of branch routers and broadband routers apparatus for use in access control, namely, network routers, gateway routers in the nature of computer control hardware, VPN (virtual private network) hardware; communication devices for linking computer networks, namely, computer network adapters, network routers, gateway routers in the nature of computer control hardware, VPN (virtual private network) hardware, LAN (local area network) hardware, computer hardware in the nature of wireless access point (WAP) devices, computer hardware in the nature of thin client access point devices, network routers in the nature of branch routers and broadband routers; communication routing systems, namely, network routers, telephone call routers, gateway routers in the nature of computer control hardware, VPN (virtual private network) hardware, LAN (local area network) hardware, computer hardware in the nature of wireless access point (WAP) devices, computer hardware in the nature of thin client access point devices, network routers in the nature of branch routers and broadband routers; communications systems, namely, communications computers, communications servers, LAN (local area network) hardware, computer hardware in the nature of wireless access point (WAP) devices, computer hardware in the nature of thin client access point devices, network routers in the nature of branch routers and broadband routers; communications networks, namely, computer network server, computer network hubs; computer hardware; computer network apparatus, namely, computer network servers, computer networking hardware; computer network installations, namely, network routers, telephone call routers, gateway routers in the nature of computer control hardware, VPN (virtual private network) hardware, computer network switches, network servers, WAN (wide area network) hardware, LAN (local area network) hardware, wireless routers, wireless adapters used to link computers to a telecommunications network; computer network apparatus, namely, computer network servers, computer networking hardware; computer network installations, namely, network routers, telephone call routers, gateway routers in the nature of computer control hardware, VPN (virtual private network) hardware, computer network switches, network servers, WAN (wide area network) hardware, LAN (local area network) hardware, wireless routers, wireless adapters used to link computers to a telecommunications network; computer networks, namely, computer network servers, computer networking hardware; computer software and programs for administration of computer networks, operating and maintaining computer networking infrastructure and security, operating and maintaining wireless networking infrastructure and security, operating and maintaining telecommunications networking infrastructure and security, VPN (virtual private network) operating software, WAN (wide area network) operating software, computer utility software; computer utility programs; computer software for implementing and enforcing user policy limits related to network bandwidth, network transmission volume, concurrent access limits, and related metrics and for generating statistics and reports related to such usage for business and technical purposes; interfaces and peripheral devices for computer systems; network management apparatus, namely, computers for network management, computer network servers, computer hardware in the nature of wireless access point (WAP) devices, computer hardware in the nature of thin client access point devices, network routers in the nature of branch routers and broadband routers; network management control apparatus, namely, computer network adapters, network routers, gateway routers in the nature of computer control hardware, VPN (virtual private network) hardware, computer hardware in the nature of wireless access point (WAP) devices, computer hardware in the nature of thin client access point devices, network routers in the nature of branch routers and broadband routers; telecommunications apparatus and devices, namely, communications computers, communications servers, gateway routers in the nature of computer control hardware, VPN (virtual private network) hardware, computer network switches, network servers, WAN (wide area network) hardware, LAN (local area network) hardware, wireless routers, wireless adapters used to link computers to a telecommunications network, computer hardware in the nature of wireless access point (WAP) devices, computer hardware in the nature of thin client access point devices, network routers in the nature of branch routers and broadband routers