L2TP (Layer 2 Tunneling Protocol)

An industry-standard Internet tunneling protocol. Unlike Point-to-Point Tunneling Protocol (PPTP), L2TP does not require IP connectivity between the client workstation and the server. L2TP requires only that the tunnel medium provide packet-oriented point-to-point connectivity. The protocol can be used over media such as ATM, Frame Relay, and X.25. L2TP provides the same functionality as PPTP. Based on Layer 2 Forwarding (L2F) and PPTP specifications, L2TP allows clients to set up tunnels across intervening networks.