A protocol for organizing virtual private networks (VPNs). It provides traffic tunneling in networks based on IP, X.25, Frame Relay, and ATM technologies. Unlike other VPN specifications, L2TP does not have its own means of data encryption, and is often used in conjunction with the IPSec protocol. L2TP/IPSec is supported by most modern hardware, and is considered to be one of the safest data transfer standards. The disadvantage of L2TP is its low speed of operation compared to OpenVPN.