MPLS Extension Header Architecture
draft-andersson-mpls-eh-architecture-00

Document Type Active Internet-Draft (individual)
Last updated 2019-02-13
Stream (None)
Intended RFC status (None)
Formats plain text pdf html bibtex
Stream Stream state (No stream defined)
Consensus Boilerplate Unknown
RFC Editor Note (None)
IESG IESG state I-D Exists
Telechat date
Responsible AD (None)
Send notices to (None)
MPLS Working Group                                          L. Andersson
Internet-Draft                                  Bronze Dragon Consulting
Intended status: Informational                               J. Guichard
Expires: August 17, 2019                                         H. Song
                                                               S. Bryant
                                                     Huawei Technologies
                                                       February 13, 2019

                   MPLS Extension Header Architecture
                draft-andersson-mpls-eh-architecture-00

Abstract

   Extension Headers (EH) carry information on in-network services and
   functions in an MPLS network.  This document describes an
   architecture for EHs and what actions an EH capable Label Switching
   Router (LSR) takes when finding or not finding an EH in the packet.

   Multiprotocol Label Switching (MPLS) is a widely deployed forwarding
   technology.  It uses label stack entries that are pre-pended to
   either the EH or the ACH which in turn is pre-pended to the payload.
   The label stack entries are used to identify the forwarding actions
   by each LSR.  Actions may include pushing, swapping or popping the
   labels, and using the labels to determine the next hop for forwarding
   the packet.  Labels may also be used to establish the context under
   which the packet is forwarded.

   The extension headers are carried after the MPLS Label Stack, and the
   presence of EHs are indicated in the label stack by an Extension
   Header Indicator (EHI).

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on August 17, 2019.

Andersson, et al.        Expires August 17, 2019                [Page 1]
Internet-Draft               EH Architecture               February 2019

Copyright Notice

   Copyright (c) 2019 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Requirement Language  . . . . . . . . . . . . . . . . . .   4
   2.  Specification . . . . . . . . . . . . . . . . . . . . . . . .   4
     2.1.  Extension Header Overview . . . . . . . . . . . . . . . .   4
     2.2.  Extension Header Terminology  . . . . . . . . . . . . . .   4
   3.  Extension Header Basics . . . . . . . . . . . . . . . . . . .   5
     3.1.  General Principles  . . . . . . . . . . . . . . . . . . .   5
     3.2.  LSPs in a EH capable Network  . . . . . . . . . . . . . .   5
     3.3.  EH capable nodes  . . . . . . . . . . . . . . . . . . . .   6
     3.4.  EH path and LSP . . . . . . . . . . . . . . . . . . . . .   6
     3.5.  Announcement of EH Capability . . . . . . . . . . . . . .   7
     3.6.  LSP establishment with LDP Downstream on Demand (DoD) in
           an EH capable network . . . . . . . . . . . . . . . . . .   7
     3.7.  LSP establishment with LDP Downstream Unsolicited (DU) in
           an EH capable network . . . . . . . . . . . . . . . . . .   9
     3.8.  Forwarding Behavior of EH Capable Nodes . . . . . . . . .  10
     3.9.  EH for RSVP-TE tunnels  . . . . . . . . . . . . . . . . .  11
     3.10. Ways to indicate an EH after the Label Stack  . . . . . .  11
   4.  EH in VPNs  . . . . . . . . . . . . . . . . . . . . . . . . .  11
   5.  EH and MPLS-SR  . . . . . . . . . . . . . . . . . . . . . . .  11
   6.  Extension Header Applications . . . . . . . . . . . . . . . .  11
   7.  EH distribution and EH capability announcement  . . . . . . .  12
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  12
   9.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  12
   10. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  12
Show full document text