L2TPv3 is an evolution to the "Layer 2 Tunneling Protocol" defined in
RFC2661. L2TP was originally designed to carry more than one link-type
if needed; however, since its origin resided in the pppext WG, the focus
of L2TP was PPP only. After the formation of the L2TPEXT WG, multiple
proposals were submitted to carry various link-types over L2TP (circa
2000). L2TPv3 was created as a way to consolidate these ideas into a
common protocol. The WG decided to organize the documents
hierarchically, with one base L2TPv3 specification comprised of the vast
majority of the protocol and encapsulation definition to be followed by
specific documents for describing each specific link-type.
This document describes the specifics of how to use the
L2TP control plane for Asynchronous Transfer Mode (ATM) Pseudo-Wires and
guidelines for transporting various ATM services over an IP network.
Working Group Summary
The most challenging task this WG faced with respect to L2TPv3 was
extracting the base document from RFC2661. The "follow-on" documents
were relatively simple after that task was completed.
There has been cross-wg contention with respect to L2TPv3, largely in
that it is sometimes postulated as an IP-based alternative to some of
the VPN functionality being put into MPLS (e.g., with L2TPv3 you can
setup pseudo wires without an MPLS-enabled core network).
Protocol quality has been assured through detail WG and individual
review by Ignacio Goyret and Ron da Silva.
This document was reviewed for the IESG by Margaret Wasserman.