An IP VPN consists of a set of protocols that provides businesses with secure connections between locations – whether over the public Internet or across carriers’ private IP networks – that are shared by other users. IP VPNs use comprehensive security measures to ensure the privacy and safe passage of business data, including encryption, encapsulation, authentication, and authorization. IP security protocol (IPSec), point-to-point tunneling protocol (PPTP), and Layer 2 tunneling protocol (L2TP) define various forms of encryption and authentication.