IP Virtual Private Network (IP VPN, IP Virtual Private Networks) -  Uses Internet Protocol for transmission in a VPN.

Virtual Private Network, or VPN, is a private communications network usually used within a company, or by several different entities, to communicate over a public network. VPN message traffic is carried on public networking infrastructure (such as the Internet) using standard (often insecure) protocols, or over a service provider's network providing that the VPN service is guarded by a well defined Service Level Agreement (SLA) between the VPN customer and the VPN service provider. http://en.wikipedia.org/wiki/Virtual_private_networks