RFC 3437 (rfc3437) - Page 1 of 10
Layer-Two Tunneling Protocol Extensions for PPP Link Control Protocol Negotiation
Alternative Format: Original Text Document
Network Working Group W. Palter
Request for Comments: 3437 zev.net
Category: Standards Track W. Townsley
Cisco Systems
December 2002
Layer-Two Tunneling Protocol Extensions for
PPP Link Control Protocol Negotiation
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2002). All Rights Reserved.
Abstract
This document defines extensions to the Layer Two Tunneling Protocol
(L2TP) for enhanced support of link-specific Point to Point Protocol
(PPP) options. PPP endpoints typically have direct access to the
common physical media connecting them and thus have detailed
knowledge about the media that is in use. When the L2TP is used, the
two PPP peers are no longer directly connected over the same physical
media. Instead, L2TP inserts a virtual connection over some or all
of the PPP connection by tunneling PPP frames over a packet switched
network such as IP. Under some conditions, an L2TP endpoint may need
to negotiate PPP Link Control Protocol (LCP) options at a location
which may not have access to all of the media information necessary
for proper participation in the LCP negotiation. This document
provides a mechanism for communicating desired LCP options between
L2TP endpoints in advance of PPP LCP negotiation at the far end of an
L2TP tunnel, as well as a mechanism for communicating the negotiated
LCP options back to where the native PPP link resides.
Palter & Townsley Standards Track