L2TP is a tunneling protocol used to create virtual networks. Its main advantage is the ability to create virtual networks not only over IP networks, but also in Frame Relay, X.25 and ATM networks. Despite being similar to the OSI link layer protocol, L2TP is a session layer protocol using UDP port 1701.
The development of the protocol can be traced back to 1997, and in 1999, the RFC2661 standard appeared, describing it. It is believed that L2TP combined the best of both L2F and PPTP.
Scheme of work
To establish a connection, the remote system through the PSTN telephone network initiates a PPP Continue reading