Browse Prior Art Database

Layer Two Tunneling Protocol "L2TP" (RFC2661)

IP.com Disclosure Number: IPCOM000003251D
Original Publication Date: 1999-Aug-01
Included in the Prior Art Database: 2000-Sep-13

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

W. Townsley: AUTHOR [+6]

Abstract

This document describes the Layer Two Tunneling Protocol (L2TP). STD 51, RFC 1661 specifies multi-protocol access via PPP [RFC1661]. L2TP facilitates the tunneling of PPP packets across an intervening network in a way that is as transparent as possible to both end-users and applications.

This text was extracted from a ASCII document.
This is the abbreviated version, containing approximately 2% of the total text.

Network Working Group W. Townsley

Request for Comments: 2661 A. Valencia

Category: Standards Track cisco Systems

A. Rubens

Ascend Communications

G. Pall

G. Zorn

Microsoft Corporation

B. Palter

Redback Networks

August 1999

Layer Two Tunneling Protocol "L2TP"

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 (1999). All Rights Reserved.

Abstract

This document describes the Layer Two Tunneling Protocol (L2TP). STD

51, RFC 1661 specifies multi-protocol access via PPP [RFC1661]. L2TP

facilitates the tunneling of PPP packets across an intervening

network in a way that is as transparent as possible to both end-users

and applications.

Table of Contents

1.0 Introduction.......................................... 3

1.1 Specification of Requirements......................... 4

1.2 Terminology........................................... 4

2.0 Topology.............................................. 8

3.0 Protocol Overview..................................... 9

3.1 L2TP Header Format.................................... 9

3.2 Control Message Types................................. 11

4.0 Control Message Attribute Value Pairs................. 12

4.1 AVP Format............................................ 13

4.2 Mandatory AVPs........................................ 14

4.3 Hiding of AVP Attribute Values........................ 14

4.4 AVP Summary........................................... 17

4.4.1 AVPs Applicable To All Control Messages.......... 17

4.4.2 Result and Error Codes........................... 18

4.4.3 Control Connection Management AVPs............... 20

4.4.4 Call Management AVPs..........................