RFC 3031 (rfc3031) - Page 1 of 61
Multiprotocol Label Switching Architecture
Alternative Format: Original Text Document
Network Working Group E. Rosen
Request for Comments: 3031 Cisco Systems, Inc.
Category: Standards Track A. Viswanathan
Force10 Networks, Inc.
R. Callon
Juniper Networks, Inc.
January 2001
Multiprotocol Label Switching Architecture
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 (2001). All Rights Reserved.
Abstract
This document specifies the architecture for Multiprotocol Label
Switching (MPLS).
Table of Contents
1 Specification ...................................... 3
2 Introduction to MPLS ............................... 3
2.1 Overview ........................................... 4
2.2 Terminology ........................................ 6
2.3 Acronyms and Abbreviations ......................... 9
2.4 Acknowledgments .................................... 9
3 MPLS Basics ........................................ 9
3.1 Labels ............................................. 9
3.2 Upstream and Downstream LSRs ....................... 10
3.3 Labeled Packet ..................................... 11
3.4 Label Assignment and Distribution .................. 11
3.5 Attributes of a Label Binding ...................... 11
3.6 Label Distribution Protocols ....................... 11
3.7 Unsolicited Downstream vs. Downstream-on-Demand .... 12
3.8 Label Retention Mode ............................... 12
3.9 The Label Stack .................................... 13
3.10 The Next Hop Label Forwarding Entry (NHLFE) ........ 13
3.11 Incoming Label Map (ILM) ........................... 14
Rosen, et al. Standards Track
