L2TP
Updated: 04/26/2017 by Computer Hope
Short for Layer 2 Tunneling Protocol, L2TP is a tunneling, Session Layer protocol, using the UDP (user datagram protocol) port 1701 on a VPN (virtual private network). It does not include any encryption and relies on other methods to provide data security and privacy, such as IPsec.
L2TP is used as a tunneling mechanism to resell ADSL (asymmetric digital subscriber line) connectivity by cable providers and companies providing a connection to their employees from outside the office.