Network Working Group                                      Adrian Farrel
Internet Draft                                        Old Dog Consulting
Category: Standards Track
Expires: July 2004                                    Arun Satyanarayana
                                                    Movaz Networks, Inc.

                                                            January 2004

      Identification of Component Links of Unnumbered Interfaces

Status of this Memo

   This document is an Internet-Draft and is in full
   conformance with all provisions of Section 10 of RFC2026.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups. Note that other
   groups may also distribute working documents as Internet-Drafts.

   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."

   The list of current Internet-Drafts can be accessed at

   The list of Internet-Draft Shadow Directories can be
   accessed at


   This document provides a means to identify component links that are
   bundled within an unnumbered interface. This feature is required
   during Generalized Multiprotocol Label Switching (GMPLS)
   establishment of Label Switched Paths (LSPs) that utilize such
   component links. Similarly, it is useful in error reporting for
   such LSPs.

0. Summary for Sub-IP Area

(This section to be removed before publication as an RFC).

0.1. Summary

0.2. Related documents

   See the References Sections.

0.3. Where does it fit in the Picture of the Sub-IP Work

   This work is applicable to GMPLS signaling protocols.

Farrel and Satyanarayana                                          Page 1

draft-farrel-ccamp-ifid-unnum-00.txt                        January 2004

0.4. Why is it Targeted at this WG

   GMPLS is worked on by the CCAMP WG.

   This is a core requirement for GMPLS signaling and reporting
   errors on unnumbered links. This makes it immediately in scope.

0.5. Justification

   [RFC3471] and [RFC3473] define how component links of numbered
   bundles may be identified within the IF_ID PHOP and IF_ID
   ERROR_SPEC objects.

   [RFC3477] defines how unnumbered links may be used in RSVP-TE.

   [RFC3471] and [RFC3473] define how unnumbered links may be identified
   within the IF_ID PHOP and IF_ID ERROR_SPEC objects.

   There is no provision for identifying component links of unnumbered
   bundles within the IF_ID PHOP and IF_ID ERROR_SPEC objects. This is
   required for completeness and to allow full functionality of GMPLS.

1. Introduction

   GMPLS offers support for bundled links to presented as a single
   interface [RFC3471, RFC3473]. This has configuration and management

   GMPLS [RFC3471, RFC3473] recognises the value of specifying
   interfaces both during LSP establishment for out-of-band signaling
   (IF_ID PHOP object), and for error reporting (IF_ID ERROR_SPEC
   object). This is achieved using TLVs in these objects to specify the
   interface identifier. Both numbered and unnumbered interfaces are

   Further, GMPLS [RFC3471, RFC3473] recognises the value of specifying
   the component link of a link bundle during LSP establishment (IF_ID
   PHOP object), and for error reporting (IF_ID ERROR_SPEC object). This
   is achieved using TLVs in these objects to specify the interface
   identifier and component link identifier. Numbered bundles of
   component links are supported. However, no provision is made for
   unnumbered bundles of component links.

   This document extends the TLV definitions of [RFC3471] to provide the
   means to identify component links of unnumbered bundles within the
   IF_ID PHOP and IF_ID ERROR_SPEC objects.

2. Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   document are to be interpreted as described in [RFC2119]

Farrel and Satyanarayana                                          Page 2

draft-farrel-ccamp-ifid-unnum-00.txt                        January 2004

3. Existing Interface Identifiers

   [RFC3471] defines IF_ID TLVs to identify links. These TLVs
   are applied in [RFC3473] in the IF_ID PHOP Object during LSP
   establishment, and in the IF_ID ERROR_SPEC Object to identify the
   failed link which is usually the downstream link from the reporting

   The following set of TLVs are defined in [RFC3471].

   Type Length Format     Description
    1      8   IPv4 Addr. IPv4                    (Interface address)
    2     20   IPv6 Addr. IPv6                    (Interface address)
    3     12   Compound   IF_INDEX                (Interface index)
    4     12   Compound   COMPONENT_IF_DOWNSTREAM (Component interface)
    5     12   Compound   COMPONENT_IF_UPSTREAM   (Component interface)

4. New Interface Identifiers

   Two new TLVs are defined for use in the IF_ID PHOP Object and in the
   IF_ID ERROR_SPEC Object. Note that the Type values shown here are
   only suggested values - final values are TBD and to be determined by
   IETF consensus.

   Two TLVs are provided to allow the forward and reverse paths to be
   separately identified.

   Type Length Format     Description
    6     16   See below  UNUM_COMPONENT_IF_DOWN  (Component interface)
    7     16   See below  UNUM_COMPONENT_IF_UP    (Component interface)

4.1 TLV Definitions

   The new TLVs have a common format as shown below.

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      |                            IP Address                         |
      |                           Interface ID                        |
      |                           Component ID                        |

       IP Address: 32 bits

          Any IP address associated with the local node.

       Interface ID: 32 bits

          The identifier of the unnumbered bundled link. By definition,
          this is unique within the scope of the node identified by
          the IP Address field.

Farrel and Satyanarayana                                          Page 3

draft-farrel-ccamp-ifid-unnum-00.txt                        January 2004

       Component ID: 32 bits

          A component in the bundled link identified by the Interface
          ID. During LSP establishment, the special value 0xFFFFFFFF can
          be used to indicate the same label to be valid across all
          component links in the bundle identified by the Interface ID.

4.1 Procedures

   The procedures are unmodified from [RFC3471], [RFC3473] and

5. IANA Considerations


   Note that the IF_ID TLV type values are not currently tracked or
   managed by IANA. This might be a good opportunity to move them under
   IANA control.

6. Security Considerations

   The extensions in this document make no changes to the security
   provisions in [RFC3473].

7. Acknowledgments

   We would like to thank the authors of [CRANKBACK] where these
   proposals originally appeared.

8. Intellectual Property Considerations

   The IETF takes no position regarding the validity or scope of any
   intellectual property or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
   might or might not be available; neither does it represent that it
   has made any effort to identify any such rights.  Information on the
   IETF's procedures with respect to rights in standards-track and
   standards-related documentation can be found in BCP-11.  Copies of
   claims of rights made available for publication and any assurances of
   licenses to be made available, or the result of an attempt made to
   obtain a general license or permission for the use of such
   proprietary rights by implementors or users of this specification can
   be obtained from the IETF Secretariat.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights which may cover technology that may be required to practice
   this standard.  Please address the information to the IETF Executive

Farrel and Satyanarayana                                          Page 4

draft-farrel-ccamp-ifid-unnum-00.txt                        January 2004

9. Normative References

   [RFC2119]      Bradner, S., "Key words for use in RFCs to Indicate
                  Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC3471]      Berger, L., Editor, "Generalized Multi-Protocol
                  Label Switching (GMPLS) Signaling Functional
                  Description", RFC 3471, January 2003.

   [RFC3473]      L. Berger, et al., "Generalized MPLS Signaling -
                  RSVP-TE Extensions", RFC 3473, January 2003.

   [RFC3477]      Kompella, K., Rekhter, Y., "Signalling Unnumbered
                  Links in RSVP-TE", RFC 3477, January 2003.

10. Informational References

   [CRANKBACK]    A. Farrel (editor), "Crankback Signaling Extensions
                  for MPLS Signaling", draft-ietf-ccamp-crankback-01.txt
                  January 2004, work in progress.

11. Authors' Addresses

   Adrian Farrel (editor)
   Old Dog Consulting
   Phone:  +44 (0) 1978 860944

   Arun Satyanarayana
   Movaz Networks, Inc.
   7926 Jones Branch Drive, Suite 615
   McLean, VA 22102
   Phone:  (+1) 703-847-1785

12. Full Copyright Statement

   Copyright (c) The Internet Society (2004). All Rights
   Reserved. This document and translations of it may be
   copied and furnished to others, and derivative works that
   comment on or otherwise explain it or assist in its
   implementation may be prepared, copied, published and
   distributed, in whole or in part, without restriction of
   any kind, provided that the above copyright notice and
   this paragraph are included on all such copies and
   derivative works. However, this document itself may not
   be modified in any way, such as by removing the copyright
   notice or references to the Internet Society or other
   Internet organizations, except as needed for the purpose
   of developing Internet standards in which case the
   procedures for copyrights defined in the Internet
   Standards process must be followed, or as required to
   translate it into languages other than English.

   The limited permissions granted above are perpetual and
   will not be revoked by the Internet Society or its
   successors or assigns.

Farrel and Satyanarayana                                          Page 5

draft-farrel-ccamp-ifid-unnum-00.txt                        January 2004

   This document and the information contained herein is
   provided on an "AS IS" basis and THE INTERNET SOCIETY AND

Farrel and Satyanarayana                                          Page 6