The Layer Two Tunneling Protocol (L2TP) was developed in the 1990s as a successor to Point-to-Point Tunneling Protocol (PPTP) by a consortium that included Microsoft and Cisco. The protocol takes features from PPTP and Cisco’s L2F (Layer 2 Forwarding) protocol to resolve some of the PPTP limitations. L2TP is native to both Windows and macOS operating systems. Details of original L2TP implementation are available from the Internet Engineering Task Force (IETF) open standards organization. A later version of this protocol, L2TPv3, has been developed to enhance the encapsulation process and security improvements.