L2TP stands for layer 2 tunneling protocol working at the link layer (layer 2) of the OSI network model. L2TP is defined by RFC 2661 and is an extension of PPP (point to Point protocol). L2TP is used for VPN tunneling. L2TP does not provide data confidentiality and it does not provide strong authentication. Other protocols such as IPSec can be used for providing confidentiality and integrity.