💾 Archived View for radia.bortzmeyer.org › rfc-mirror › rfc5329.txt captured on 2024-07-09 at 03:50:13.

View Raw

More Information

⬅️ Previous capture (2023-06-14)

-=-=-=-=-=-=-







Network Working Group                                        K. Ishiguro
Request for Comments: 5329                                     V. Manral
Category: Standards Track                               IP Infusion, Inc
                                                                A. Davey
                                                 Data Connection Limited
                                                          A. Lindem, Ed.
                                                        Redback Networks
                                                          September 2008


            Traffic Engineering Extensions to OSPF Version 3

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 IETF Trust (2008).

Abstract

   This document describes extensions to OSPFv3 to support intra-area
   Traffic Engineering (TE).  This document extends OSPFv2 TE to handle
   IPv6 networks.  A new TLV and several new sub-TLVs are defined to
   support IPv6 networks.





















Ishiguro, et al.            Standards Track                     [Page 1]

RFC 5329               OSPFv3-Traffic Engineering         September 2008


Table of Contents

   1. Introduction ....................................................2
      1.1. Requirements Notation ......................................2
   2. Intra-Area-TE-LSA ...............................................3
      2.1. Intra-Area-TE-LSA Payload ..................................4
   3. Router IPv6 Address TLV .........................................4
   4. Link TLV ........................................................5
      4.1. Link ID Sub-TLV ............................................6
      4.2. Neighbor ID Sub-TLV ........................................6
      4.3. Local Interface IPv6 Address Sub-TLV .......................6
      4.4. Remote Interface IPv6 Address Sub-TLV ......................7
   5. Security Considerations .........................................8
   6. Management Considerations .......................................8
   7. IANA Considerations .............................................9
   8. References ......................................................9
      8.1. Normative References .......................................9
      8.2. Informative References ....................................10
   Acknowledgments ...................................................10

1.  Introduction

   OSPFv3 has a very flexible mechanism for adding new LS types.
   Unknown LS types are flooded properly based on the flooding scope
   bits in the LS type [OSPFV3].  This document defines the Intra-Area-
   TE-LSA to OSPFv3.

   For Traffic Engineering, this document uses "Traffic Engineering
   Extensions to OSPF" [TE] as a base for TLV definitions.  New TLVs and
   sub-TLVs are added to [TE] to extend TE capabilities to IPv6
   networks.  Some existing TLVs and sub-TLVs require clarification for
   OSPFv3 applicability.

   GMPLS [GMPLS] and the Diff-Serv MPLS extensions [TE-DIFF] are based
   on [TE].  These functions can also be extended to OSPFv3 by utilizing
   the TLVs and sub-TLVs described in this document.

1.1.  Requirements Notation

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119
   [RFC-KEYWORDS].








Ishiguro, et al.            Standards Track                     [Page 2]

RFC 5329               OSPFv3-Traffic Engineering         September 2008


2.  Intra-Area-TE-LSA

   A new LS type is defined for the Intra-Area-TE-LSA.  This is
   different from OSPFv2 Traffic Engineering [TE] where opaque LSAs are
   used to advertise TE information [OPAQUE].  The LSA function code is
   10, the U-bit is set, and the scope is set to 01 for area-scoping.
   When the U-bit is set to 1, an OSPFv3 router must flood the LSA at
   its defined flooding scope even if it does not recognize the LS type
   [OSPFV3].

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |            LS age             |1|0|1|          10             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                    Link State ID                              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                    Advertising Router                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                    LS sequence number                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |        LS checksum            |            Length             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      +-                            TLVs                             -+
      |                             ...                               |

                           OSPFv3 Intra-Area-TE-LSA

   The Link State ID of an Intra-Area-TE-LSA is an arbitrary value used
   to maintain multiple Traffic Engineering LSAs.  The Link State ID has
   no topological significance.

   The format of the TLVs within the body of an Intra-Area-TE-LSA is the
   same as the format used by the Traffic Engineering extensions to OSPF
   [TE].  The LSA payload consists of one or more nested
   Type/Length/Value (TLV) triplets.  The format of each TLV is:

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |              Type             |             Length            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                            Value...                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                                  TLV Format




Ishiguro, et al.            Standards Track                     [Page 3]

RFC 5329               OSPFv3-Traffic Engineering         September 2008


   The Length field defines the length of the value portion in octets
   (thus, a TLV with no value portion would have a length of 0).  The
   TLV is padded to 4-octet alignment; padding is not included in the
   Length field (so a 3-octet value would have a length of 3, but the
   total size of the TLV would be 8 octets).  Nested TLVs are also 32-
   bit aligned.  For example, a 1-byte value would have the Length field
   set to 1, and 3 octets of padding would be added to the end of the
   value portion of the TLV.  Unrecognized types are ignored.

2.1.  Intra-Area-TE-LSA Payload

   An Intra-Area-TE-LSA contains one top-level TLV.  There are two
   applicable top-level TLVs:

      2 - Link TLV

      3 - Router IPv6 Address TLV

3.  Router IPv6 Address TLV

   The Router IPv6 Address TLV advertises a reachable IPv6 address.
   This is a stable IPv6 address that SHOULD be reachable if there is
   connectivity to the OSPFv3 router.

   The Router IPv6 Address TLV has type 3, length 16, and a value
   containing a 16-octet local IPv6 address.  A link-local address MUST
   NOT be specified for this TLV.  It MUST appear in exactly one Traffic
   Engineering LSA originated by an OSPFv3 router supporting the TE
   extensions.  The Router IPv6 Address TLV is a top-level TLV as
   defined in "Traffic Engineering Extensions to OSPF" [TE], and only
   one top-level TLV may be contained in an LSA.




















Ishiguro, et al.            Standards Track                     [Page 4]

RFC 5329               OSPFv3-Traffic Engineering         September 2008


       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |              3                |            16                 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      +-+-+-+-                                                 -+-+-+-+
      |                                                               |
      +-+-+-+-             Router IPv6 Address                 -+-+-+-+
      |                                                               |
      +-+-+-+-                                                 -+-+-+-+
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      Type    A 16-bit field set to 3.
      Length  A 16-bit field that indicates the length of the value
              portion in octets.  For this TLV, it is always 16.
      Value   A stable and routable IPv6 address.

                           Router IPv6 Address TLV

4.  Link TLV

   The Link TLV describes a single link and consists of a set of sub-
   TLVs [TE].  All of the sub-TLVs in [TE] other than the Link ID sub-
   TLV are applicable to OSPFv3.  The Link ID sub-TLV can't be used in
   OSPFv3 since it is defined to use the OSPFv2 identification for the
   Designated Router (DR) on multi-access networks.  In OSPFv2,
   neighbors on point-to-point networks and virtual links are identified
   by their Router IDs while neighbors on broadcast, Non-Broadcast
   Multi-Access (NBMA), and Point-to-Multipoint links are identified by
   their IPv4 interface addresses (refer to section 8.2 in [OSPFV2]).
   The IPv4 interface address is not known to OSPFv3.  In contrast to
   OSPFv2, OSPFv3 always identifies neighboring routers by their Router
   IDs (refer to section 2.11 in [OSPFV3]).

   Three new sub-TLVs for the Link TLV are defined:

      18 - Neighbor ID (8 octets)

      19 - Local Interface IPv6 Address (16N octets, where N is the
           number of IPv6 addresses)

      20 - Remote Interface IPv6 Address (16N octets, where N is the
           number of IPv6 addresses)






Ishiguro, et al.            Standards Track                     [Page 5]

RFC 5329               OSPFv3-Traffic Engineering         September 2008


   The Neighbor ID sub-TLV is mandatory for OSPFv3 Traffic Engineering
   support.  It MUST appear exactly once in a Link TLV.  All other sub-
   TLVs defined in this document SHOULD NOT occur more than once in a
   Link TLV.  If a sub-TLV is specified more than once, instances
   subsequent to the first are ignored.

4.1.  Link ID Sub-TLV

   The Link ID sub-TLV is used in OSPFv2 to identify the other end of
   the link.  In OSPFv3, the Neighbor ID sub-TLV MUST be used for link
   identification.  In OSPFv3, the Link ID sub-TLV SHOULD NOT be sent
   and MUST be ignored upon receipt.

4.2.  Neighbor ID Sub-TLV

   In OSPFv2, the Link ID is used to identify the other end of a link.
   In OSPFv3, the combination of Neighbor Interface ID and Neighbor
   Router ID is used for neighbor link identification.  Both are
   advertised in the Neighbor ID sub-TLV.

   Neighbor Interface ID and Neighbor Router ID values are the same as
   described in RFC 5340 [OSPFV3], A.4.3 Router-LSAs.

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |              18               |             8                 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |             Neighbor Interface ID                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |             Neighbor Router ID                                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      Type    A 16-bit field set to 18.
      Length  A 16-bit field that indicates the length of the value
              portion in octets.  For this sub-TLV, it is always 8.
      Value   The neighbor's Interface ID and Router ID.

                             Neighbor ID Sub-TLV

4.3.  Local Interface IPv6 Address Sub-TLV

   The Local Interface IPv6 Address sub-TLV specifies the IPv6
   address(es) of the interface corresponding to this link.  If there
   are multiple local addresses assigned to the link, then they MAY all
   be listed in this sub-TLV.  Link-local addresses MUST NOT be included
   in this sub-TLV.




Ishiguro, et al.            Standards Track                     [Page 6]

RFC 5329               OSPFv3-Traffic Engineering         September 2008


       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |              19               |              Length           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      +-+-+-+-                                                 -+-+-+-+
      |                                                               |
      +-+-+-+-          Local Interface IPv6 Address           -+-+-+-+
      |                                                               |
      +-+-+-+-                                                 -+-+-+-+
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                         o                                     |
      |                         o                                     |
      |                         o                                     |
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      +-+-+-+-                                                 -+-+-+-+
      |                                                               |
      +-+-+-+-          Local Interface IPv6 Address           -+-+-+-+
      |                                                               |
      +-+-+-+-                                                 -+-+-+-+
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      Type    A 16-bit field set to 19.
      Length  A 16-bit field that indicates the length of the value
              portion in octets.  For this sub-TLV, it MUST always be a
              multiple of 16 octets dependent on the number of IPv6
              global addresses advertised.
      Value   A list of one or more local IPv6 interface addresses each
              consuming 16 octets.

                         Local Interface IPv6 Address Sub-TLV

4.4.  Remote Interface IPv6 Address Sub-TLV

   The Remote Interface IPv6 Address sub-TLV advertises the IPv6
   address(es) associated with the neighbor's interface.  This sub-TLV
   and the Local Interface IPv6 Address sub-TLV are used to discern
   amongst parallel links between OSPFv3 routers.  If the link type is
   multi-access, the Remote Interface IPv6 Address MAY be set to ::.
   Alternately, an implementation MAY choose not to send this sub-TLV.
   Link-local addresses MUST NOT be advertised in this sub-TLV.
   Neighbor addresses advertised in link-LSAs with a prefix length of
   128 and the LA-bit set MAY be advertised.



Ishiguro, et al.            Standards Track                     [Page 7]

RFC 5329               OSPFv3-Traffic Engineering         September 2008


       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |              20               |              Length           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      +-+-+-+-                                                 -+-+-+-+
      |                                                               |
      +-+-+-+-             Remote Interface IPv6 Address       -+-+-+-+
      |                                                               |
      +-+-+-+-                                                 -+-+-+-+
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                         o                                     |
      |                         o                                     |
      |                         o                                     |
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      +-+-+-+-                                                 -+-+-+-+
      |                                                               |
      +-+-+-+-             Remote Interface IPv6 Address       -+-+-+-+
      |                                                               |
      +-+-+-+-                                                 -+-+-+-+
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      Type    A 16-bit field set to 20.
      Length  A 16-bit field that indicates the length of the value
              portion in octets.  For this sub-TLV, it MUST be a
              multiple of 16 octets dependent on the number of IPv6
              global addresses advertised.
      Value   A variable-length Remote Interface IPv6 Address list.

                    Remote Interface IPv6 Address Sub-TLV

5.  Security Considerations

   The function described in this document does not create any new
   security issues for the OSPFv3 protocol.  Security considerations for
   the base OSPFv3 protocol [OSPFV3] and OSPFv2 Traffic Engineering [TE]
   are applicable to OSPFv3 Traffic Engineering.

6.  Management Considerations

   The typical management interface for routers running the new
   extensions to OSPF for intra-area Traffic Engineering is Simple
   Network Management Protocol (SNMP) based.  The extra management



Ishiguro, et al.            Standards Track                     [Page 8]

RFC 5329               OSPFv3-Traffic Engineering         September 2008


   objects for configuration operations and statistics are defined in
   [OSPFV3-MIB], and an implementation of the extensions defined in this
   document SHOULD provide for the appropriate hooks or instrumentation
   that allow for the MIB objects to be implemented.

   The following MIB variables have been added to the OSPFv3 MIB in
   support of TE:

   ospfv3AreaTEEnabled
      This TruthValue MIB variable in the ospfv3AreaEntry table entry
      indicates whether or not OSPFv3 TE advertisement for OSPFv3
      interfaces is enabled for the corresponding area.  The default
      value is FALSE.

   ospfv3IfTEDisabled
      This TruthValue MIB variable in the ospfv3IfEntry table entry
      indicates whether or not OSPFv3 TE advertisement for OSPFv3 for
      the corresponding interface is disabled.  This MIB variable is
      only applicable if ospfv3AreaTEEnabled is TRUE for the interface's
      area.  The default value is FALSE.

7.  IANA Considerations

   The following IANA assignments have been made from existing
   registries:

   1. The OSPFv3 LSA type function code 10 has been assigned to the
      OSPFv3 Intra-Area-TE-LSA.

   2. The Router IPv6 Address TLV type 3 has been assigned from the
      existing registry for OSPF TE TLVs.

   3. The Neighbor ID (18), Local Interface IPv6 Address (19), and
      Remote Interface IPv6 Address (20) sub-TLVs have been assigned
      from the existing registry for OSPF TE sub-TLVs.

8.  References

8.1.  Normative References

   [OSPFV2]       Moy, J., "OSPF Version 2", STD 54, RFC 2328, April
                  1998.

   [OSPFV3]       Coltun, R., Ferguson, D., Moy, J., and A. Lindem,
                  "OSPF for IPv6", RFC 5340, July 2008.

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



Ishiguro, et al.            Standards Track                     [Page 9]

RFC 5329               OSPFv3-Traffic Engineering         September 2008


   [TE]           Katz, D., Kompella, K., and D. Yeung, "Traffic
                  Engineering (TE) Extensions to OSPF Version 2", RFC
                  3630, September 2003.

8.2.  Informative References

   [GMPLS]        Kompella, K., Ed., and Y. Rekhter, Ed., "OSPF
                  Extensions in Support of Generalized Multi-Protocol
                  Label Switching (GMPLS)", RFC 4203, October 2005.

   [OPAQUE]       Berger, L., Bryskin, I., Zinin, A., and R. Coltun,
                  "The OSPF Opaque LSA Option", RFC 5250, July 2008.

   [OSPFV3-MIB]   Joyal, D. and V. Manral, "Management Information Base
                  for OSPFv3", Work in Progress, September 2007.

   [TE-DIFF]      Le Faucheur, F., Wu, L., Davie, B., Davari, S.,
                  Vaananen, P., Krishnan, R., Cheval, P., and J.
                  Heinanen, "Multi-Protocol Label Switching (MPLS)
                  Support of Differentiated Services", RFC 3270, May
                  2002.

Acknowledgments

   Thanks to Kireeti Kompella, Alex Zinin, Adrian Farrell, and Mach Chen
   for their comments.

   Thanks to Vijay K. Gurbani for providing the General Area Review Team
   (Gen-ART) review.

   Thanks to Rob Austein for providing the Security Directorate (secdir)
   review.

   Thanks to Dan Romascanu for providing the text for the "Management
   Considerations" section in the context of the IESG review.

   Thanks to Dave Ward, Tim Polk, Jari Arkko, and Pasi Eronen for
   comments and relevant discussion in the context of the IESG review.

   The RFC text was produced using Marshall Rose's xml2rfc tool.











Ishiguro, et al.            Standards Track                    [Page 10]

RFC 5329               OSPFv3-Traffic Engineering         September 2008


Authors' Addresses

   Kunihiro Ishiguro
   IP Infusion, Inc.
   1188 East Arques Avenue,
   Sunnyvale, CA  94085
   USA

   EMail: kunihiro@ipinfusion.com


   Vishwas Manral
   IP Infusion, Inc
   #41, Ground Floor, 5th Cross Road
   8th Main Road
   Vasanth Nagar, Bangalore  560052
   India

   EMail: vishwas@ipinfusion.com


   Alan Davey
   Data Connection Limited
   100 Church Street
   Enfield
   EN2 6BQ
   UK

   EMail: Alan.Davey@dataconnection.com


   Acee Lindem
   Redback Networks
   102 Carric Bend Court
   Cary, NC  27519
   USA

   EMail: acee@redback.com













Ishiguro, et al.            Standards Track                    [Page 11]

RFC 5329               OSPFv3-Traffic Engineering         September 2008


Full Copyright Statement

   Copyright (C) The IETF Trust (2008).

   This document is subject to the rights, licenses and restrictions
   contained in BCP 78, and except as set forth therein, the authors
   retain all their rights.

   This document and the information contained herein are provided on an
   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
   THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
   OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
   THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Intellectual Property

   The IETF takes no position regarding the validity or scope of any
   Intellectual Property Rights 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; nor does it represent that it has
   made any independent effort to identify any such rights.  Information
   on the procedures with respect to rights in RFC documents can be
   found in BCP 78 and BCP 79.

   Copies of IPR disclosures made to the IETF Secretariat 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 implementers or users of this
   specification can be obtained from the IETF on-line IPR repository at
   http://www.ietf.org/ipr.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights that may cover technology that may be required to implement
   this standard.  Please address the information to the IETF at
   ietf-ipr@ietf.org.












Ishiguro, et al.            Standards Track                    [Page 12]