Network Service Header Metadata Type 2 Variable-Length Context Headers
draft-ietf-sfc-nsh-tlv-06

Document Type Active Internet-Draft (sfc WG)
Authors Yuehua Wei  , Uri Elzur  , Sumandra Majee  , Carlos Pignataro 
Last updated 2021-06-01 (latest revision 2021-05-12)
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Send notices to gregimirsky@gmail.com
SFC                                                          Y. Wei, Ed.
Internet-Draft                                           ZTE Corporation
Intended status: Standards Track                                U. Elzur
Expires: November 13, 2021                                         Intel
                                                                S. Majee
                                                  Individual contributor
                                                            C. Pignataro
                                                                   Cisco
                                                            May 12, 2021

 Network Service Header Metadata Type 2 Variable-Length Context Headers
                       draft-ietf-sfc-nsh-tlv-06

Abstract

   Service Function Chaining (SFC) uses the Network Service Header (NSH)
   [RFC8300] to steer and provide context Metadata (MD) with each
   packet.  Such Metadata can be of various Types including MD Type 2
   variable length context headers.  This document specifies several
   such context headers that can be used within a service function path.

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
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   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
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   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on November 13, 2021.

Copyright Notice

   Copyright (c) 2021 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

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   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  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions used in this document . . . . . . . . . . . . . .   3
     2.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
     2.2.  Requirements Language . . . . . . . . . . . . . . . . . .   3
   3.  NSH MD Type 2 format  . . . . . . . . . . . . . . . . . . . .   3
   4.  NSH MD Type 2 Context Headers . . . . . . . . . . . . . . . .   4
     4.1.  Forwarding Context  . . . . . . . . . . . . . . . . . . .   4
     4.2.  Tenant Identifier . . . . . . . . . . . . . . . . . . . .   5
     4.3.  Ingress Network Node Information  . . . . . . . . . . . .   6
     4.4.  Ingress Network Source Interface  . . . . . . . . . . . .   6
     4.5.  Flow ID . . . . . . . . . . . . . . . . . . . . . . . . .   7
     4.6.  Source and/or Destination Groups  . . . . . . . . . . . .   7
     4.7.  Policy Identifier (POLICY_ID) . . . . . . . . . . . . . .   8
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   8
   6.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   8
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   9
     7.1.  Forwarding Context Types  . . . . . . . . . . . . . . . .   9
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   9
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  10
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  10
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  11

1.  Introduction

   The Network Service Header (NSH) [RFC8300] is the Service Function
   Chaining (SFC) encapsulation required to support the SFC architecture
   [RFC7665].  As such, the NSH provides following key elements:

   1.  Service Function Path identification.

   2.  Indication of location within a Service Function Path.

   3.  Optional, per-packet metadata (fixed-length or variable-length).

   [RFC8300] further defines two metadata formats (MD Types): 1 and 2.
   MD Type 1 defines the fixed-length, 16-octet long metadata, whereas
   MD Type 2 defines a variable-length context format for metadata.
   This document defines serveral common metadata context headers for
   use with NSH MD Type 2.  These supplement the Subscriber Identity and

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   Performance Policy MD Type 2 metadata context headers specified in
   [RFC8979].

   This document does not address metadata usage, updating/chaining of
   metadata, or other SFP functions.  Those topics are described in
   [RFC8300].

2.  Conventions used in this document

2.1.  Terminology

   This document uses the terminology defined in the SFC Architecture
   [RFC7665] and the Network Service Header [RFC8300].

2.2.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

3.  NSH MD Type 2 format

   An NSH is composed of a 4-octet Base Header, a 4-octet Service Path
   Header and Context Headers.  The Base Header identifies the MD-Type
   in use:

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |Ver|O|U|    TTL    |   Length  |U|U|U|U|MD Type| Next Protocol |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                         Figure 1: NSH Base Header

   Please refer to NSH [RFC8300] for a detailed header description.

   When the base header specifies MD Type = 0x2, zero or more Variable
   Length Context Headers MAY be added, immediately following the
   Service Path Header.  Therefore, Length = 0x2 indicates that only the
   Base Header followed by the Service Path Header is present.  The
   value of the Length field, of optional Variable Length Context
   Headers, MUST be an integer indicating the length in 4-octet words.
   Figure 2 below depicts the format of the Context Header as defined in
   Section 2.5.1 of [RFC8300].

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        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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |          Metadata Class       |      Type     |U|    Length   |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                   Variable-Length Metadata                    |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

               Figure 2: NSH Variable-Length Context Headers

4.  NSH MD Type 2 Context Headers

   [RFC8300] specifies Metadata Class 0x0000 as IETF Base NSH MD Class.
   In this document, metadata types are defined for the IETF Base NSH MD
   Class.

4.1.  Forwarding Context

   This metadata context carries a network forwarding context, used for
   segregation and forwarding scope.  Forwarding context can take
   several forms depending on the network environment.  For example,
   VXLAN/VXLAN-GPE VNID, VRF identification, or VLAN.

       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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Metadata Class = 0x0000    |  Type = TBA1  |U|  Length = 4 |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |   CT  |             Reserved          | Forwarding Context ID |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                     Figure 3: Forwarding Context - 1

       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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Metadata Class = 0x0000    |  Type = TBA1  |U|  Length = 4 |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |   CT  |   Reserved    |          Forwarding Context ID        |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                     Figure 4: Forwarding Context - 2

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       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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Metadata Class = 0x0000    |  Type = TBA1  |U|  Length = 4 |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |   CT  | Resv  |              Forwarding Context ID            |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                     Figure 5: Forwarding Context - 3

        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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Metadata Class = 0x0000    |  Type = TBA1  |U|  Length = 8 |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |   CT  |             Reserved                                  |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                      Forwarding Context ID                    |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                     Figure 6: Forwarding Context - 4

   where:

      Context Type (CT) is four bits-long field that defines the length
      and the interpretation of the Tenant ID field.  Please see the
      IANA Considerations in Section 7.  This document defines these CT
      values:

         0x0 - 12 bits VLAN identifier.  See Figure Figure 3.  Reserved
         bits MUST be sent as zero and ignored on receipt

         0x1 - 20 bits MPLS VPN label.  See Figure Figure 4.  Reserved
         bits MUST be sent as zero and ignored on receipt

         0x2 - 24 bits virtual network identifier (VNI).  See
         Figure Figure 5.  Reserved bits MUST be sent as zero and
         ignored on receipt

         0x3 - 32 bits Session ID ([RFC3931]).  This is called Key in
         GRE [RFC2890].  See Figure Figure 6.

4.2.  Tenant Identifier

   Tenant identification is often used for segregation within a multi-
   tenant environment.  Orchestration system-generated tenant IDs are an
   example of such data.  This context header carries both the format
   and value of the Tenant identifier.

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       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |    Metadata Class = 0x0000    |  Type = TBA2  |U|    Length   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      ~                         Tenant ID                             ~
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                     Figure 7: Tenant Identifier List

   The fields are described as follows: Length: Indicates the length of
   the Tenant ID in bytes (see Section 2.5.1 of [RFC8300]).  Tenant ID:
   Represents an opaque value pointing to Orchestration system-generated
   tenant identifier.  The structure and semantics of this field are
   deployment specific.

4.3.  Ingress Network Node Information

   This context header carries a Node ID of the ingress network node.

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |    Metadata Class = 0x0000    |  Type = TBA3  |U| Length = var|
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      ~                        Node ID                                ~
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                     Figure 8: Ingress Network Node ID

   where:

      The fields are described as follows: Length: Indicates the length
      of the Node ID in bytes (see Section 2.5.1 of [RFC8300]).  Node
      ID: Represents an opaque value of the ingress network node ID.
      The structure and semantics of this field are deployment specific.
      For example, Node ID may be a 4 bytes IPv4 address Node ID, or a
      16 bytes IPv6 address Node ID, or a 6 bytes MAC address, or 8
      bytes MAC address, etc,.

4.4.  Ingress Network Source Interface

   This context identifies the ingress interface of the ingress network
   node.  This is an opaque quantity to the NSH.

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       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |    Metadata Class = 0x0000    |  Type = TBA4  |U| Length = var|
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      ~                     Source Interface/Port                     ~
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                Figure 9: Ingress Network Source Interface

4.5.  Flow ID

   Flow ID provides a field in the NSH MD Type 2 to label packets
   belonging to the same flow.  Absence of this field, or a value of
   zero denotes that packets have not been labeled.

   [RFC6437] defined IPv6 Flow Label as a 20-bit long unsigned integer.
   Also, [RFC6790], which defined the use of an entropy label in the
   MPLS network, is 20-bit long.  The Flow ID is right justified
   (appears in the least significant bits of the Flow ID word) and is
   padded on the left with bits which MUST be sent as zero and ignored
   on receipt.

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |    Metadata Class = 0x0000    |  Type = TBA5  |U| Length = var|
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      ~                     Flow ID                                   ~
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                            Figure 10: Flow ID

4.6.  Source and/or Destination Groups

   Intent-based systems can use this data to express the logical
   grouping of source and/or destination objects.  [GROUPBASEDPOLICY]
   and [GROUPPOLICY] provide examples of such a system.  Each is
   expressed as a 32-bit opaque object.

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       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |    Metadata Class = 0x0000    |  Type = TBA6  |U|  Length=8   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Source Group                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Dest Group                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                       Figure 11: Source/Dest Groups

4.7.  Policy Identifier (POLICY_ID)

   Traffic handling policies are often referred to by a system-generated
   identifier, which is then used by the devices to look up the policy's
   content locally.  For example, this identifier could be an index to
   an array, a lookup key, a database Id.  The identifier allows
   enforcement agents or services to lookup up the content of their part
   of the policy quite efficiently.  This identifier is treated as an
   opaque value.

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |    Metadata Class = 0x0000    |  Type = TBA7  |U|  Length=var |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      ~                     POLICY_ID                                  ~
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                           Figure 12: POLICY_ID

5.  Security Considerations

   [RFC8300] describes the general security considerations for
   protecting NSH.  [I-D.ietf-sfc-nsh-integrity] specifies methods of
   protecting NSH metadata.

6.  Acknowledgments

   The authors would like to thank Paul Quinn, Behcet Sarikaya, Dirk von
   Hugo, Mohamed Boucadair, Gregory Mirsky, Joel Halpern, Donald
   Eastlake for providing invaluable concepts and content for this
   document.

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7.  IANA Considerations

   IANA is requested to assign the following types from the "NSH IETF-
   Assigned Optional Variable-Length Metadata Types" (0x0000 IETF Base
   NSH MD Class) registry available at [IANA-NSH-MD2]:

   This document defines the following new values (Table 1) in the
   Network Service Header (NSH) metadata context Type registry:

       +-------+----------------------------------+---------------+
       | Value |           Description            | Reference     |
       +-------+----------------------------------+---------------+
       | TBA1  |        Forwarding Context        | This document |
       | TBA2  |        Tenant Identifier         | This document |
       | TBA3  |      Ingress Network NodeID      | This document |
       | TBA4  |    Ingress Network Interface     | This document |
       | TBA5  |             Flow ID              | This document |
       | TBA6  | Source and/or Destination Groups | This document |
       | TBA7  |        Policy Identifier         | This document |
       +-------+----------------------------------+---------------+

                           Table 1: Type Values

7.1.  Forwarding Context Types

   IANA is requested to create a new sub-registry for "Forwarding
   Context" context types at [IANA-NSH-MD2] as follows:

   +---------+-----------------------------------------+---------------+
   | Value   |     Forwarding Context Header Types     | Reference     |
   +---------+-----------------------------------------+---------------+
   | 0x0     |          12-bit VLAN identifier         | This document |
   | 0x1     |          20-bits MPLS VPN label         | This document |
   | 0x2     |    24-bits virtual network identifier   | This document |
   |         |                  (VNI)                  |               |
   | 0x3     |            32-bit Session ID            | This document |
   | 0x4-0xE |                Unassigned               | IETF Review   |
   | 0xF     |                 Reserved                | This document |
   +---------+-----------------------------------------+---------------+

                     Table 2: Forwarding Context Types

8.  References

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8.1.  Normative References

   [I-D.ietf-sfc-nsh-integrity]
              Boucadair, M., Reddy, T., and D. Wing, "Integrity
              Protection for the Network Service Header (NSH) and
              Encryption of Sensitive Context Headers", draft-ietf-sfc-
              nsh-integrity-05 (work in progress), March 2021.

   [IANA-NSH-MD2]
              IANA, "NSH IETF-Assigned Optional Variable-Length Metadata
              Types", <https://www.iana.org/assignments/nsh/
              nsh.xhtml#optional-variable-length-metadata-types>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC3931]  Lau, J., Ed., Townsley, M., Ed., and I. Goyret, Ed.,
              "Layer Two Tunneling Protocol - Version 3 (L2TPv3)",
              RFC 3931, DOI 10.17487/RFC3931, March 2005,
              <https://www.rfc-editor.org/info/rfc3931>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8300]  Quinn, P., Ed., Elzur, U., Ed., and C. Pignataro, Ed.,
              "Network Service Header (NSH)", RFC 8300,
              DOI 10.17487/RFC8300, January 2018,
              <https://www.rfc-editor.org/info/rfc8300>.

8.2.  Informative References

   [GROUPBASEDPOLICY]
              OpenStack, "Group Based Policy", 2014.

   [GROUPPOLICY]
              OpenDaylight, "Group Policy", 2014.

   [RFC2890]  Dommety, G., "Key and Sequence Number Extensions to GRE",
              RFC 2890, DOI 10.17487/RFC2890, September 2000,
              <https://www.rfc-editor.org/info/rfc2890>.

   [RFC6437]  Amante, S., Carpenter, B., Jiang, S., and J. Rajahalme,
              "IPv6 Flow Label Specification", RFC 6437,
              DOI 10.17487/RFC6437, November 2011,
              <https://www.rfc-editor.org/info/rfc6437>.

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   [RFC6790]  Kompella, K., Drake, J., Amante, S., Henderickx, W., and
              L. Yong, "The Use of Entropy Labels in MPLS Forwarding",
              RFC 6790, DOI 10.17487/RFC6790, November 2012,
              <https://www.rfc-editor.org/info/rfc6790>.

   [RFC7665]  Halpern, J., Ed. and C. Pignataro, Ed., "Service Function
              Chaining (SFC) Architecture", RFC 7665,
              DOI 10.17487/RFC7665, October 2015,
              <https://www.rfc-editor.org/info/rfc7665>.

   [RFC8979]  Sarikaya, B., von Hugo, D., and M. Boucadair, "Subscriber
              and Performance Policy Identifier Context Headers in the
              Network Service Header (NSH)", RFC 8979,
              DOI 10.17487/RFC8979, February 2021,
              <https://www.rfc-editor.org/info/rfc8979>.

Authors' Addresses

   Yuehua (Corona) Wei (editor)
   ZTE Corporation
   No.50, Software Avenue
   Nanjing  210012
   China

   Email: wei.yuehua@zte.com.cn

   Uri Elzur
   Intel

   Email: uri.elzur@intel.com

   Sumandra Majee
   Individual contributor

   Email: Sum.majee@gmail.com

   Carlos Pignataro
   Cisco

   Email: cpignata@cisco.com

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