MPLS Working Group                                          L. Andersson
Internet-Draft                                  Bronze Dragon Consulting
Updates: 8029, 8611 (if approved)                                M. Chen
Intended status: Standards Track                      Huawei Techologies
Expires: March 28, April 26, 2021                                     C. Pignataro
                                                           Cisco Systems
                                                                 T. Saad
                                                        Juniper Networks
                                                      September 24,
                                                        October 23, 2020

               Updating the IANA MPLS LSP Ping Parameters
             draft-ietf-mpls-lsp-ping-registries-update-04
             draft-ietf-mpls-lsp-ping-registries-update-05

Abstract

   This document updates RFC 8029 and RFC 8611 that both define IANA
   registries for MPLS LSP Ping.  It also updates the description of the
   procedures for the responses sent when an unknown or erroneous code
   point is found.  The updates are to clarify and align this name space
   with recent developments.

Status of This Memo

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   provisions of BCP 78 and BCP 79.

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   This Internet-Draft will expire on March 28, April 26, 2021.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Requirement Language  . . . . . . . . . . . . . . . . . .   3   4
     1.2.  Terminology Used in this Document . . . . . . . . . . . .   4
   2.  Updating the Message Types, Reply Mode and Return Codes
       Registries  . . . . . . . . . . . . . . . . . . . . . . . . .   4   5
   3.  Updating the TLV and Sub-TLV Registries . . . . . . . . . . .   5
     3.1.  General Principles for the LSP Ping TLV and Sub-TLV
           registries  . . . . . . . . . . . . . . . . . . . . . . .   5
       3.1.1.  Unrecognized Experimental Use TLVs and Sub-TLVs . . .   6
     3.2.  Common Registration Procedures for TLVs and sub-TLVs  . .   6
     3.3.  Changes to the LSP Ping Registries  . . . . . . . . . . .   7
       3.3.1.  Common Changes to the TLV and Sub-TLV Registries  . .   7
   4.  Updates to Related RFCs . . . . . . . . . . . . . . . . . . .   8
     4.1.  Updates to RFC 8029 . . . . . . . . . . . . . . . . . . .   8
     4.2.  Updates to RFC 8611 . . . . . . . . . . . . . . . . . . .   9
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  10
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10  11
     6.1.  Updates to the Message Type, Reply Mode and Return Codes
           Registries  . . . . . . . . . . . . . . . . . . . . . . .  11
       6.1.1.  Updates to the Mesage Message Type registry  . . . . . . . . .  11
       6.1.2.  Updates to the Reply Modes registry . . . . . . . . .  12
       6.1.3.  Updates to the Return Codes registry  . . . . . . . .  13
     6.2.  Updates to the TLV and sub-TLV Sub-TLV registries . . . . . . . .  16
       6.2.1.  Updates to the TLVs registry  . . . . . . . . . . . .  16
       6.2.2.  Updates to the registry for SubTLVs for TLVs 1, 16
               and 21  . . . . . . . . . . . . . . . . . . . . . . .  18
       6.2.3.  Updates to the registry for SubTLVs for TLV 6 . . . .  20
       6.2.4.  Updates to the registry for SubTLVs for TLV 11  . . .  22
       6.2.5.  Updates to the registry for SubTLVs Sub-TLVs for TLV 20 . . .  24
       6.2.6.  Updates to the registry for SubTLVs for TLV 23  . . .  26
       6.2.7.  Updates to the registry for SubTLVs for TLV 27  . . .  28
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  30
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  30
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  30
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  32
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  33

1.  Introduction

   There were a few reasons to start the work that have led to this
   document, e.g.:

   o  When the LSP Ping registry was created it was incorrectly assumed
      that code points allocated by Experimental RFCs would be
      'experimental' code points; a code point made available in a
      public IANA registry is not limited by the type of RDFC that made
      the allocation but is available for any document.

   o  The number of 'experimental' code points was also too large, as
      compared to what we normally allocated for "Experimental Use".

   o  RFC 8029 uses the words "mandatory" and "optional" differently
      from what others RFC does.  RFC 8029 for example talks about
      mandatory TLVs to indicate that it is mandatory to take a certain
      action if the TLV is found in a message but not recognized, other
      RFCs uses "mandatory TLV" to indicate a TLV that must be present
      in a message.

   Over time there has been attempts administratively update some of the
   registries, but it was soon decided the an RFC was needed.  We also
   found other, often minor, potential updates, e.g. reserving the value
   0 (zero) in registries there that is possible.

   When RFC 8029 [RFC8029] was published it contained updates to the
   "Multiprotocol Label Switching (MPLS) Label Switched Paths (LSPs)
   Ping Parameters" IANA name space [IANA-LSP-PING].

   RFC 8611 [RFC8611] updated the LSP Ping IANA registries to match RFC
   8029.  This document further clarifies the entries in those
   registries and makes the definitions more precise.

   This document updates RFC 8029 [[RFC8029] and RFC 8611 [RFC8611] by
   updating two groups of registries as follows:

   First the registries for Message Types [IANA-MT], Reply Modes
   [IANA-RM] and Return Codes [IANA-RC] are updated.  The changes to
   these registries are minor.

   Second, this document updates the TLV and sub-TLV registries.

   o  TLVs [IANA-TLV-reg].

   o  Sub-TLVs for TLVs 1, 16 and 21 [IANA-Sub-1-16-21].

   o  Sub-TLVs for TLV Type 6 [IANA-Sub-6].

   o  Sub-TLVs for TLV 11 [IANA-Sub-11].

   o  Sub-TLVs for TLV 20 [IANA-Sub-20].

   o  Sub-TLVs for TLV 23 [IANA-Sub-23].

   o  Sub-TLVs for TLV 27 [IANA-Sub-27].

   The registry for sub-TLVs for TLV 9 [IANA-Sub-9] is not updated.

   Third, some code points (TLVs and sub-TLVs) are "mandatory" or
   "optional".  Contrary to how other RFCs use these words, indicating
   that it is mandatory or optional to include the code points in a
   message, RFC 8029 uses these words to indicate that an action might
   or might not be necessary.  This document updates RFC 8029 to drop
   the words "mandatory" and "optional", and the text is changed to
   focus on what should be done.

1.1.  Requirement 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.

1.2.  Terminology Used in this Document

   This docuemtment document uses some terms that relates to IANA registries in this
   way:

      IANA Name Space,
      a name space is a top level registry.  An exasmple example could be
      "Multiprotocol Label Switching (MPLS) Label Switched Paths (LSPs)
      Ping Parameters" [IANA-LSP-PING].  A name space is most often a
      contaimer
      container for regiistries registries that hold code points that share some
      affinity.

      IANA Registry,
      an IANA registry holds code points, and lists the registration
      procedures and allocation of code points these code points.  One
      example would be the "TLVs" registry [IANA-TLV-reg].

      IANA Sub-registry,
      a sub-registry is used when a code point allocated in point, or a registry
      need set of code points
      allocated in a single registry, needs "sub-code points" scoped by that
      the code point or a the set of code points.  An example of a sunregistry thast sub-
      registry that holds code points for more than one TLV is
      "Sub-TLVs for TLV Types 1, 16, and 21" [IANA-Sub-1-16-21]

2.  Updating the Message Types, Reply Mode and Return Codes Registries

   The following changes are made to the Message Types, Reply Modes and
   Return Codes [IANA-MT] registries.

   o  In the listing of assiged assigned code points the term "Vendor Private
      Use" is changed to "Private Use".

   o  The registration procedure "Specification Required" is changed to
      "RFC Required" and the note "Experimental RFC needed" is removed.

   o  A small set of code points (4 code points) for Experimental Use is
      added by reducing the range for "RFC Required" range.

   o  The registration procedures "Private Use" and "Experimental Use"
      are added to the table of registration procedures.

   o  A note "Not to be assigned" is added for the registration
      procedures "Private Use" and "Experimental Use".

   o  In the lists that capture the assignment status, the fields that
      are reserved, i.e. i.e., 0 (zero), Private Use and Experimental Use are
      clearly marked as such.

      *  Note that in the Return Codes registry [IANA-RC] registry the code point
         "0" has already been assigned.  This assignment is not changed
         and in this registry the code point "0" continues to be
         assigned as "No Return Code".

   The new Registration Procedures, the registry layouts and the new
   assignments for these registries are found in Section 6.1.

3.  Updating the TLV and Sub-TLV Registries

3.1.  General Principles for the LSP Ping TLV and Sub-TLV registries

   The following principles apply to the processing of any TLV from any
   of the LSP Ping TLV and sub-TLV IANA registries.

   o  All TLVs and sub-TLVs with a type in the range 0-32767 require a
      response if they are not recognized.

   o  All TLVs and sub-TLVs in the range 32768-65535 may be silently
      dropped, stepped over or an error message sennt sent if they are not
      recognized.

   The range of each TLV and sub-TLV registry is divided into two
   blocks, one with a range from 0 to 32767 for TLVs and sub-TLVs that
   require a response if not recognized.  The other block has the range
   from 32768 to 65535 for TLVs and sub-TLVs that may be silently
   dropped, stepped over or an error message sent, if not recognized.

   Each of the blocks has code point spaces with the following
   registration procedures:

   o  Standards Action.

   o  RFC Required.

   o  Experimental Use.

   o  First come, first served Come First Served (FCFS).

   The exact defintions definitions of these procedures are found in [RFC8126].

3.1.1.  Unrecognized Experimental Use TLVs and Sub-TLVs

   Unrecognized TLVs and sub-TLVs in the Experimetal Experimental Use, and FCFS
   ranges are handled as any other unrecognized TLV or sub-TLV.

   o  If the unrecognized TLV or sub-TLV is from the Experimental Use
      range (37140-37143) (37140-31743) or from the FCFS range (31744-32767) a the Return
      Code of 2 ("One or more of the TLVs was not understood") will be
      sent in the echo response.

   o  If the unrecognized TLV or sub-TLV is from the Experimental Use
      range (64508-64511).  or (64508-64511)or from the FCFS range (64512-65535) the TLVs
      may be silently ignored, stepped over or an error message sent.

   The IETF does not prescribe how recognized or unrecognized
   Experimental Use and Private Use TLVs and sub-TLVs are handled in
   experimental or private networks, that is up to the agency running
   the experiment or the private network.  The statement above describes
   how standards compliant implementations will treat the unrecognized
   TLVs and sub- TLVs sub-TLVs from these ranges.

3.2.  Common Registration Procedures for TLVs and sub-TLVs

   This section describes the new registration procedures for the TLV
   and sub-TLV registries.

   +-------------+-------------------+---------------------------------+
   | Range       | Registration      | Note                            |
   |             | Procedures        |                                 |
   +-------------+-------------------+---------------------------------+
   | 0-16383     | Standards Action  | This range is for TLVs and sub- |
   |             |                   | TLVs that require an error      |
   |             |                   | message if not recognized.      |
   |             |                   | [This document, section 3.1]    |
   | 16384-31739 | RFC Required      | This range is for TLVs an and sub- |
   |             |                   | TLVs that require an error      |
   |             |                   | message if not recognized.      |
   | 37140-37143             |                   | [This document, section 3.1]    |
   | 31740-31743 | Experimental Use  | Reserved, not to be assigned    |
   | 31744-32767 | FCFS              | This range is for TLVs anf and sub- |
   |             |                   | TLVs that require an error      |
   |             |                   | message if not recognized.      |
   |             |                   | [This document, section 3.1]    |
   | 32768-49161 | Standards Action  | This range is for TLVs and sub- |
   |             |                   | TLVs that can be silently       |
   |             |                   | dropped if not recognized.      |
   | 49162-64507 | RFC Required      | This range is for TLVs and sub- |
   |             |                   | TLVs that can be silently       |
   |             |                   | dropped if not recognized.      |
   | 64508-64511 | Experimental Use  | Reserved, not to be assigned    |
   | 64512-65535 | FCFS              | This range is for TLVs and sub- |
   |             |                   | TLVs that can be silently       |
   |             |                   | dropped if not recognized.      |
   +-------------+-------------------+---------------------------------+

             Table 1: TLV and sub-TLV Registration Procedures

3.3.  Changes to the LSP Ping Registries

   This section lists the changes to each MPLS LSP Ping TLV and sub-TLV
   Registry, see section 6.2.1 to 6.2.7 describe how the new versions of
   the IANA registries should look, together with the registration
   procedures for each registry.

   The new Registration Procedures description and the new assignments
   for these registries are used to model the changed MPLS LSP Ping
   registries, see Section 6 .

3.3.1.  Common Changes to the TLV and Sub-TLV Registries

   The following changes are made to the TLV and sub-TLV registries.

   o  The registration procedures "First Come Frst First Served (FCFS)" and
      "Experimental Use" are added to the table of registration
      procedures.

   o  Two small sets of code points (4 code points each) for
      Experiemental
      Experimental Use, are created.  The first set are is for the range
      that requires a response if the TLV or sub-TLV is not recognised; recognized;
      the second set are is for the range there the TLV or sub-TLV that may
      be silently dropped if not recognized.  The code points for
      experimental use are actually taken from the two ranges now called
      "RFC Required".

   o  The registration procedure "Specification Required" is changed to
      "RFC Required" and the note "Experimental RFC needed" is removed.

   o  In the listing of assignments the term "Vendor Private Use" is
      changed to "First Come First Served (FCFS)".

   o  In the listing of assignments the range for "Experimental Use" is
      added.

   o  A note saying "Not to be assigned" is added for the registration
      procedures "Experimental Use".

   o  In the list that captures assignment status, the fields that are
      reserved, i.e. i.e., 0 (zero) and Experimental Use are clearly marked.

4.  Updates to Related RFCs

   Some referenced RFCs use the concept "mandatory TLVs" and "mandatory
   sub-TLVs" to indicate that, if a TLV or sub-TLV of the range 0-16383
   or 16384-31743 0-32767
   in a message is not understood, an error message needs to be sent in
   response.

   The same RFCs use "optional TLVs" and "optional sub-TLVs" to mean
   TLVs or sub-TLVs that can be silently ignored if not recognized.

   Since other RFCs use "mandatory TLVs" and "mandatory sub-TLVs" to
   indicate TLVs and sub-TLVs that must be present in a message, we want
   to discontinue the use of "mandatory" to indicate TLVs and sub-TLVs
   that requires an error message in response if not understood.  The
   changes to the RFCs below align with this practice.

4.1.  Updates to RFC 8029

   Mandatory and optional are used to indicate whether a response is
   needed if a TLV or sub-TLV is not understood on pages 14 and 15 in
   Section 3 of RFC 8029.

   The text in those two paragraphs are is now updated to the following:

      TLV and sub-TLV Types less than 32768 (i.e., with the high-order
      bit equal to 0) are TLVs and sub-TLVs that MUST either be
      supported by an implementation or result in the Return Code of 2
      ("One or more of the TLVs was not understood") being sent in the
      echo response.

      An implementation that does not understand or support a received
      TLV or sub-TLV with Type greater than or equal to 32768 (i.e.,
      with the high-order bit equal to 1) SHOULD ignore and step over
      the TLV or sub-TLV, however an implementation MAY send an echo
      response with Return Code 2 ("One or more of the TLVs was not
      understood") as it would have done if the high order bit had been
      clear.

   In Section 3.8 of RFC 8029 "mandatory" is used in the same way.  The
   first two paragraphs of this section are now updated to read as
   follows:

      The following TLV is a TLV that MAY be included in an echo reply
      to inform the sender of an echo request that includes TLVs or sub-
      TLVs Types less than 32768 (i.e., with the high-order bit equal to
      0) are either not supported by the implementation or parsed and
      found to be in error.

      The Value field contains the TLVs, including sub-TLVs, that were
      not understood, encoded as sub-TLVs.

4.2.  Updates to RFC 8611

   Section 13.4.1 of "Label Switched Path (LSP) Ping and Traceroute
   Multipath Support for Link Aggregation Group (LAG) Interfaces
   [RFC8611]" defines "Sub-TLVs for TLV Type 6" [IANA-Sub-6].

   The "Sub-TLVs for TLV Type 6" registry is now updated to align with
   changes defined in this document.

   Section 13.4.1 of RFC 8611 is now updated as follows:

   Section 13.4.1 Sub-TLVs for TLV Type 6

   IANA has created a new sub-registry "Sub-TLVs for TLV Type 6"
   [IANA-Sub-6] under the "TLVs" registry [IANA-TLV-reg] of the
   "Multiprotocol Label Switching (MPLS) Label Switched Paths (LSPs)
   Ping Parameters" name space [lsp-ping-NameSpace].

   The "Sub-TLVs for TLV Type 6" sub-registry is now updated to align
   with changes defined in this document.

   +-------------+-------------------+---------------------------------+
   | Range       | Registration      | Note                            |
   |             | Procedures        |                                 |
   +-------------+-------------------+---------------------------------+
   | 0-16383     | Standards Action  | This range is for sub-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | section 3.1]                    |
   | 16384-31739 | RFC Required      | This range is for sub-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | section 3.1]                    |
   | 31740-31743 | Experimental Use  | Reserved not to be assigned     |
   | 31744-32767 | FCFS              | This range is for sub-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | section 3.1]                    |
   | 32768-49161 | Standards Action  | This range is for sub-TLVs that |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   | 49162-64507 | RFC Required      | This range is for sub-TLVs that |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   | 64508-64511 | Experimental Use  | Reserved not to be assigned     |
   | 64512-65535 | FCFS              | This range is for sub-TLVs that |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   +-------------+-------------------+---------------------------------+

         Table 1: 2: Sub-TLVs for TLV Type 6 Registration Procedures

5.  Security Considerations

   This document updates IANA registries.  It also updates terminology
   used to define, and clarifies the terminology related to, the code
   points in the registries.  The document does not change how the code-
   points in the registries are used.  This should not create any new
   threats.

   However, the updated terminology and the clarifications improve
   security because it makes it more likely that implementations will be
   consistent and harder to attack.

6.  IANA Considerations

   IANA is requested to update the "Multiprotocol Label Switching (MPLS)
   Label Switched Paths (LSPs) Ping Parameters" name space
   [IANA-LSP-PING] as described in this document.

   See Section 1.2 "Terminology Used in this Document" to see how "name
   space", "registry" and "sub-registry" are used in this document.

   In other parts of this document the communality of the changes to the
   LSP Ping registries has been the focus.  For the IANA considerations
   each changed registry has been described in its own right.

   The following registries and sub-registries are changed:

   "Message Types", [IANA-MT],
   "Reply Modes", [IANA-RM]
   "Return Codes" [IANA-RC]
   "TLVs" [IANA-TLV-reg]
   "Sub-TLVs for TLV Types 1, 16, and 21" [IANA-Sub-1-16-21]
   "Sub-TLVs for TLV Type 6" [IANA-Sub-6]
   "Sub-TLVs for TLV Type 11" [IANA-Sub-11]
   "Sub-TLVs for TLV Type 20" [IANA-Sub-20]
   "Sub-TLVs for TLV Type 23" [IANA-Sub-23]
   "Sub-TLVs for TLV Type 27" [IANA-Sub-27]

6.1.  Updates to the Message Type, Reply Mode and Return Codes
      Registries

   This section details the updated registration procedures and
   allocations for "Message Type", "Reply Mode" and "Return Codes"
   registries.

6.1.1.  Updates to the Mesage Message Type registry

   This is the changes to the "Message Type" registry specified in this
   document:

   o  Code Point 0 (zero) is marked Resereved. Reserved.

   o  The registration procedure "Specification Required" is changed to
      "RFC Required" and the comment "Experimental RFC needed" is
      removed.

   o  Four code point has have been taken from what was earlier
      "Specification Required" to form a set of code points for
      "Experimental Use."

   The registration procedures after the changes for the "Message Type"
   registry are shown in the table below:

   +---------+--------------------+------------------------------------+
   | Range   | Registration       | Note                               |
   |         | Procedures         |                                    |
   +---------+--------------------+------------------------------------+
   | 0-191   | Standards Action   |                                    |
   | 192-247 | RFC Required       |                                    |
   | 248-251 | Experimental Use   | Reserved, not to be assigned       |
   | 252-255 | Private Use        | Reserved, not to be assigned       |
   +---------+--------------------+------------------------------------+

               Table 2: 3: Message Type registration procedures

   The updated assignments for the "Message Types" registry will look
   like this:

   +---------+---------------------------------+-----------------------+
   | Value   | Meaning                         | Reference             |
   +---------+---------------------------------+-----------------------+
   | 0       | Reserved                        | This document         |
   | 1       | MPLS Echo Request               | [RFC8029]             |
   | 2       | MPLS Echo Reply                 | [RFC8029]             |
   | 3       | MPLS Proxy Ping Request         | [RFC7555]             |
   | 4       | MPLS Proxy Ping Reply           | [RFC7555]             |
   | 5       | MPLS Relayed Echo Reply         | [RFC7743]             |
   | 6-247   | Unassigned                      |                       |
   | 248-251 | Reserved for Experimental Use   | This document         |
   | 252-255 | Reserved for Private Use        | [RFC8029]             |
   +---------+---------------------------------+-----------------------+

            Table 3: 4: Assignments for the Message Types registry

6.1.2.  Updates to the Reply Modes registry

   This is the changes to the "Reply Modes" registry specified in this
   document:

   o  Code Point 0 (zero) is marked Resereved. Reserved.

   o  The registration procedure "Specification Required" is changed to
      "RFC Required" and the comment "Experimental RFC needed" is
      removed.

   o  Four code point has have been taken from what was earlier
      "Specification Required" to form a set of code points for
      "Experimental Use".

   The registration procedures after the changes for the "Reply Modes"
   registry are show in the table below:

   +---------+--------------------+------------------------------------+
   | Range   | Registration       | Note                               |
   |         | Procedures         |                                    |
   +---------+--------------------+------------------------------------+
   | 0-191   | Standards Action   |                                    |
   | 192-247 | RFC Required       |                                    |
   | 248-251 | Experimental Use   | Reserved, not to be assigned       |
   | 252-255 | Private Use        | Reserved, not to be assigned       |
   +---------+--------------------+------------------------------------+

               Table 4: 5: Reply Modes registration procedures

   The updated assignments for the "Reply Modes" registry will look like
   this:

   +---------+---------------------------------+-----------------------+
   | Value   | Meaning                         | Reference             |
   +---------+---------------------------------+-----------------------+
   | 0       | Reserved                        | This document         |
   | 1       | Do not reply                    | [RFC8029]             |
   | 2       | Reply via an IPv4/IPv6 UDP      | [RFC8029]             |
   |         | packet                          |                       |
   | 3       | Reply via an IPv4/IPv6 UDP      | [RFC8029]             |
   |         | packet with Router Alert        |                       |
   | 4       | Reply via application-level     | [RFC8029]             |
   |         | control channel                 |                       |
   | 5       | Reply via Specified Path        | [RFC7110]             |
   | 6-247   | Unassigned                      |                       |
   | 248-251 | Reserved for Experimental Use   | This document         |
   | 252-255 | Reserved for Private Use        | [RFC8029]             |
   +---------+---------------------------------+-----------------------+

             Table 5: 6: Assignments for the Reply Modes registry

6.1.3.  Updates to the Return Codes registry

   This is the changes to the "Return Codes" registry specified in this
   document:

   o  The registration procedure "Specification Required" is changed to
      "RFC Required" and the comment "Experimental RFC needed" is
      removed.

   o  Four code point has have been taken from what was earlier
      "Specification Required" to form a set of code points for
      "Experimental Use".

   The registration procedures after the changes for the "Return Codes"
   registry are show in the table below:

   +---------+--------------------+------------------------------------+
   | Range   | Registration       | Note                               |
   |         | Procedures         |                                    |
   +---------+--------------------+------------------------------------+
   | 0-191   | Standards Action   |                                    |
   | 192-247 | RFC Required       |                                    |
   | 248-251 | Experimental Use   | Reserved, not to be assigned       |
   | 252-255 | Private Use        | Reserved, not to be assigned       |
   +---------+--------------------+------------------------------------+

               Table 6: 7: Return Codes registration procedures

   The updated assignments for the "Return Codes" registry will look
   like this:

   +---------+----------------------------------+----------------------+
   | Value   | Meaning                          | Reference            |
   +---------+----------------------------------+----------------------+
   | 0       | No Return Code                   | This document        |
   | 1       | Malformed echo request received  | [RFC8029]            |
   | 2       | One or more of the TLVs was not  | [RFC8029]            |
   |         | understood                       |                      |
   | 3       | Replying router is an egress for | [RFC8029]            |
   |         | the FEC at stack-depth (RSC)     |                      |
   | 4       | Replying router has no mapping   | [RFC8029]            |
   |         | for the FEC at stack-depth (RSC) |                      |
   | 5       | Downstream Mapping Mismatch (See | [RFC8029]            |
   |         | [1])                             |                      |
   | 6       | Upstream Interface Index Unknown | [RFC8029]            |
   |         | (See [1])                        |                      |
   | 7       | Reserved                         | [RFC8029]            |
   | 8       | Label switched at stack-depth    | [RFC8029]            |
   |         | (RSC)                            |                      |
   | 9       | Label switched but no MPLS       | [RFC8029]            |
   |         | forwarding at stack-depth (RSC)  |                      |
   | 10      | Mapping for this FEC is not the  | [RFC8029]            |
   |         | given label at stack-depth (RSC) |                      |
   | 11      | No label entry at stack-depth    | [RFC8029]            |
   |         | (RSC)                            |                      |
   | 12      | Protocol not associated with     | [RFC8029]            |
   |         | interface at FEC stack-depth     |                      |
   |         | (RSC)                            |                      |
   | 13      | Premature termination of ping    | [RFC8029]            |
   |         | due to label stack shrinking to  |                      |
   |         | a single label                   |                      |
   | 14      | See DDMAP TLV for meaning of     | [RFC8029]            |
   |         | Return Code and Return Subcode   |                      |
   |         | (See [2])                        |                      |
   | 15      | Label switched with FEC change   | [RFC8029]            |
   | 16      | Proxy Ping not authorized        | [RFC7555]            |
   | 17      | Proxy Ping parameters need to be | [RFC7555]            |
   |         | modified                         |                      |
   | 18      | MPLS Echo Request could not be   | [RFC7555]            |
   |         | sent                             |                      |
   | 19      | Replying router has FEC mapping  | [RFC7555]            |
   |         | for topmost FEC                  |                      |
   | 20      | One or more TLVs not returned    | [RFC7743]            |
   |         | due to MTU size                  |                      |
   | 21      | OAM Problem/Unsupported BFD      | [RFC7759]            |
   |         | Version                          |                      |
   | 22      | OAM Problem/Unsupported BFD      | [RFC7759]            |
   |         | Encapsulation format             |                      |
   | 23      | OAM Problem/Unsupported BFD      | [RFC7759]            |
   |         | Authentication Type              |                      |
   | 24      | OAM Problem/Mismatch of BFD      | [RFC7759]            |
   |         | Authentication Key ID            |                      |
   | 25      | OAM Problem/Unsupported          | [RFC7759]            |
   |         | Timestamp Format                 |                      |
   | 26      | OAM Problem/Unsupported Delay    | [RFC7759]            |
   |         | Mode                             |                      |
   | 27      | OAM Problem/Unsupported Loss     | [RFC7759]            |
   |         | Mode                             |                      |
   | 28      | AM Problem/Delay variation       | [RFC7759]            |
   |         | unsupported                      |                      |
   | 29      | OAM Problem/Dyadic mode          | [RFC7759]            |
   |         | unsupported                      |                      |
   | 30      | OAM Problem/Loopback mode        | [RFC7759]            |
   |         | unsupported                      |                      |
   | 31      | OAM Problem/Combined mode        | [RFC7759]            |
   |         | unsupported                      |                      |
   | 32      | OAM Problem/Fault management     | [RFC7759]            |
   |         | signaling unsupported            |                      |
   | 33      | OAM Problem/Unable to create     | [RFC7759]            |
   |         | fault management association     |                      |
   | 34      | OAM Problem/PM Configuration     | [RFC7759]            |
   |         | Error                            |                      |
   | 35      | Mapping for this FEC is not      | [RFC8287] sec 7.4    |
   |         | associated with the incoming     |                      |
   |         | interface                        |                      |
   | 36-247  | Unassigned                       | [RFC7759]            |
   | 248-251 | Reserved for Experimental Use    | This document        |
   | 252-255 | Reserved for Private Use         | [RFC8029]            |
   +---------+----------------------------------+----------------------+

            Table 7: 8: Assignments for the Return Codes registry Return Codes registry

   Notes [1] and [2] for code point 5,6 and 14 points to footnotes in
   the "Multiprotocol Label Switching (MPLS) Label Switched Paths (LSPs)
   Ping Parameters" name space.  The footnoes are not changed by this
   document.

6.2.  Updates to the TLV and sub-TLV Sub-TLV registries

   The updates to the TLV and the sub-TLV registries are mostly the
   same, however the Sub-TLVs for TLV Type 9 [IANA-Sub-9] has not been
   updated.

   Note that when a field in an assigment assignment table sayds says "EQ", it means
   that the field should not be changed as compared to the corresponding
   field in the "Multiprotocol Label Switching (MPLS) Label Switched
   Paths (LSPs) Ping Parameters" name space [IANA-LSP-PING]

6.2.1.  Updates to the TLVs registry

   This section describes the new registration procedures and the
   assignments for the "TLVs" registry [IANA-TLV-reg] based on the new
   registration procedures.

   The registration procedures has been changed the following way for
   the "TLVs" registry.

   o  The "Specification Required" registration procedure has been
      changed to "RFC Required", the comment "Experimental RFC Required"
      has been removed.

   o  The code points registration procedure "Vendor Private Use" has
      been removed and replaced with "First Come, First Served" code
      points.

   o  Two small sets, 4 code points each, has have been created for
      Experimental Use.

   o  Code points that are reserved are clearly marked as such.

   o  The assignments have been updated to match the new registration
      procedures.

   o  The notes related to the registration procedures have been changed
      to reflect when a response is required or not if a TLV is not
      recognized.

   The registration procedures for the "TLVs" registry [IANA-TLV-reg]
   will now look like this:

   +-------------+-------------------+---------------------------------+
   | Range       | Registration      | Note                            |
   |             | Procedures        |                                 |
   +-------------+-------------------+---------------------------------+
   | 0-16383     | Standards Action  | This range is for TLVs that     |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | section 3.1]                    |
   | 16384-31739 | RFC Required      | This range is for TLVs that     |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | section 3.1]                    |
   | 31740-31743 | Experimental Use  | Reserved, not to be assigned    |
   | 31744-32767 | FCFS              | This range is for TLVs that     |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | section 3.1]                    |
   | 32768-49161 | Standards Action  | This range is for TLVs that can |
   |             |                   | be silently dropped if not      |
   |             |                   | recognized.                     |
   | 49162-64507 | RFC Required      | This range is for TLVs that can |
   |             |                   | be silently dropped if not      |
   |             |                   | recognized.                     |
   | 64508-64511 | Experimental Use  | Reserved, not to be assigned    |
   | 64512-65535 | FCFS              | This range is for TLVs that can |
   |             |                   | be silently dropped if not      |
   |             |                   | recognized.                     |
   +-------------+-------------------+---------------------------------+

                   Table 8: 9: TLV Registration Procedures

   The TLV Assignments will now look like this.

   Note that when a field in this table does say "EQ", it means that if it
   should be the same as the registry being updtated.

   +-------------+---------------+-----------------+-------------------+ updated.

   +-------------+---------------+------------------+------------------+
   | Type        | TLV Name      | Reference        | Sub-TLV Registry |
   +-------------+---------------+-----------------+-------------------+
   +-------------+---------------+------------------+------------------+
   | 0           | Reserved      | This document    |                  |
   | 1-7         | EQ            | EQ               | EQ               |
   | 8           | Unassigned    |                  |                  |
   | 9-16        | EQ            | EQ               | EQ               |
   | 17-19       | unassigned    |                  |                  |
   | 20-27       | EQ            | EQ               | EQ               |
   | 28-31739    | Unassigned    |                  |                  |
   | 31740-31743 | Experimental  | This Document    | Reserved, not to |
   |             | Use           |                  | be assigned      |
   | 31744-32767 | Unassigned    |                  |                  |
   | 32768-32770 | EQ            | EQ               | EQ               |
   | 32771-64507 | EQ            | EQ               | EQ               |
   | 64508-64511 | Experimental  | This document    | Resereved, Reserved, not to |
   |             | Use           |                  | be assigned      |
   | 64512-65535 | Unassigned    |                  |                  |
   +-------------+---------------+-----------------+-------------------+
   +-------------+---------------+------------------+------------------+

                         Table 9: 10: TLV Assignments

6.2.2.  Updates to the registry for SubTLVs for TLVs 1, 16 and 21

   This section describes the new registration procedures and the
   assignments for the "Sub-TLVs for TLV Types 1, 16, and 21"
   [IANA-Sub-1-16-21] sub-registry based on the new registration
   procedures.

   o  The "Specification Required" registration procedure has been
      changed to "RFC Required", the comment "Experimental RFC Required"
      has been removed.

   o  The code points registration procedure "Vendor Private Use" has
      been removed and replaced with "First Come, First Served" code
      points.

   o  Two small sets, 4 code points each, has have been created for
      Experimental Use.

   o  Code points that are reserved are clearly marked as such.

   o  The assignments have been updated to match the new registration
      procedures.

   o  The notes related to the registration procedures have been changed
      to reflect when a response is required if a sub-TLV is not
      recognized or not.

   The registration procedures for the
   "Sub-TLVs for TLV Types 1, 16, and 21" [IANA-Sub-1-16-21] sub-
   registry will now look like this:

   +-------------+-------------------+---------------------------------+
   | Range       | Registration      | Note                            |
   |             | Procedures        |                                 |
   +-------------+-------------------+---------------------------------+
   | 0-16383     | Standards Action  | This range is for TLVs sun-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | section 3.1]                    |
   | 16384-31739 | RFC Required      | This range is for TLVs sun-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | 37140-37144 section 3.1]                    |
   | 31740-31743 | Experimental Use  | Reserved, not to be assigned    |
   | 31748-32767 31744-32767 | FCFS              | This range is for TLVs sun-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | section 3.1]                    |
   | 32768-49161 | Standards Action  | This range is for TLVs sun-TLVs that can |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   | 49162-64507 | RFC Required      | This range is for TLVs sun-TLVs that can |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   | 64508-64511 | Experimental Use  | Reserved, not to be assigned    |
   | 64512-65535 | FCFS              | This range is for TLVs sun-TLVs that can |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   +-------------+-------------------+---------------------------------+

   Table 10: 11: Registration Procedures for Sub-TLVs for TLVs 1, 16 and 21
   +-------------+---------------+-----------------+-------------------+
   | Type        | TLV Name      | Reference       | Comment           |
   +-------------+---------------+-----------------+-------------------+
   | 0           | Reserved      | This document   |                   |
   | 1-4         | EQ            | EQ              | EQ                |
   | 5           | Unassigned    |                 |                   |
   | 6-8         | EQ            | EQ              | EQ                |
   | 9           | EQ            | EQ              | DEPRECATED        |
   | 9-20 10-20       | EQ            | EQ              | EQ                |
   | 21          | unassigned    |                 |                   |
   | 22-37       | EQ            | EQ              | EQ                |
   | 38-31739    | Unassigned    |                 |                   |
   | 31740-31743 | Experimental  | This Document   | Reserved, not to  |
   |             | Use           |                 | be assigned       |
   | 31744-64507 | Unassigned    |                 |                   |
   | 64508-64511 | Experimental  | This document   | Resereved, Reserved, not to  |
   |             | Use           |                 | be assigned       |
   | 64512-65535 | Unassigned    |                 |                   |
   +-------------+---------------+-----------------+-------------------+

            Table 11: 12: Sub-TLV for TLV 1, 16 and 21 Assignments

6.2.3.  Updates to the registry for SubTLVs for TLV 6

   This section describes the new registration procedures and the
   assignments for the "Sub-TLVs for TLV Type 6" [IANA-Sub-6] sub-
   registry based on the new registration procedures.

   o  The "Specification Required" registration procedure has been
      changed to "RFC Required", the comment "Experimental RFC Required"
      has been removed.

   o  The code points registration procedure "Vendor Private Use" has
      been removed and replaced with "First Come, First Served" code
      points.

   o  Two small sets, 4 code points each, has have been created for
      Experimental Use.

   o  Code points that are reserved are clearly marked as such.

   o  The assignments have been updated to match the new registration
      procedures.

   o  The notes related to the registration procedures have been changed
      to reflect when a response is required if a sub-TLV is not
      recognized or not.

   The registration procedures for the "Sub-TLVs for TLV Type 6"
   [IANA-Sub-6] sub-registry will now look like this:

   +-------------+-------------------+---------------------------------+
   | Range       | Registration      | Note                            |
   |             | Procedures        |                                 |
   +-------------+-------------------+---------------------------------+
   | 0-16383     | Standards Action  | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | section 3.1]                    |
   | 16384-31739 | RFC Required      | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | 37140-37144 section 3.1]                    |
   | 31740-31743 | Experimental Use  | Reserved, not to be assigned    |
   | 31748-32767 31744-32767 | FCFS              | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | section 3.1]                    |
   | 32768-49161 | Standards Action  | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   | 49162-64507 | RFC Required      | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   | 64508-64511 | Experimental Use  | Reserved, not to be assigned    |
   | 64512-65535 | FCFS              | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   +-------------+-------------------+---------------------------------+

         Table 12: 13: Registration Procedures for Sub-TLVs for TLVs 6

   +-------------+---------------+-----------------+-------------------+

   +-------------+---------------+------------------+------------------+
   | Type        | TLV Name      | Reference        | Comment          |
   +-------------+---------------+-----------------+-------------------+
   +-------------+---------------+------------------+------------------+
   | 0           | Reserved      | This document    |                  |
   | 1-2         | EQ            | EQ               | EQ               |
   | 3-31739     | Unassigned    |                  |                  |
   | 31740-31743 | Experimental  | This Document    | Reserved, not to |
   |             | Use           |                  | be assigned      |
   | 31744-64507 | Unassigned    |                  |                  |
   | 64508-64511 | Experimental  | This document    | Resereved, Reserved, not to |
   |             | Use           |                  | be assigned      |
   | 64512-65535 | Unassigned    |                  |                  |
   +-------------+---------------+-----------------+-------------------+
   +-------------+---------------+------------------+------------------+

                 Table 13: 14: Sub-TLVs for TLV 6 Assignments

6.2.4.  Updates to the registry for SubTLVs for TLV 11

   This section describes the new registration procedures and the
   assignments for the "Sub-TLVs for TLV Type 11" [IANA-Sub-11] sub-
   registry based on the new registration procedures.

   o  The "Specification Required" registration procedure has been
      changed to "RFC Required", the comment "Experimental RFC Required"
      has been removed.

   o  The code points registration procedure "Vendor Private Use" has
      been removed and replaced with "First Come, First Served" code
      points.

   o  Two small sets, 4 code points each, has have been created for
      Experimental Use.

   o  Code points that are reserved are clearly marked as such.

   o  The assignments have been updated to match the new registration
      procedures.

   o  The notes related to the registration procedures have been changed
      to reflect when a response is required if a sub-TLV is not
      recognized or not.

   The registration procedures for the "Sub-TLVs for TLV Type 11"
   [IANA-Sub-11] sub-registry will now look like this:

   +-------------+-------------------+---------------------------------+
   | Range       | Registration      | Note                            |
   |             | Procedures        |                                 |
   +-------------+-------------------+---------------------------------+
   | 0-16383     | Standards Action  | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | section 3.1]                    |
   | 16384-31739 | RFC Required      | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | section 3.1]                    |
   | 37140-37144 31740-31743 | Experimental Use  | Reserved, not to be assigned    |
   | 31748-32767 31744-32767 | FCFS              | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | section 3.1]                    |
   | 32768-49161 | Standards Action  | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   | 49162-64507 | RFC Required      | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   | 64508-64511 | Experimental Use  | Reserved, not to be assigned    |
   | 64512-65535 | FCFS              | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   +-------------+-------------------+---------------------------------+

        Table 14: 15: Registration Procedures for Sub-TLVs for TLVs 11

   +-------------+---------------+-----------------+-------------------+

   +-------------+---------------+------------------+------------------+
   | Type        | TLV Name      | Reference        | Comment          |
   +-------------+---------------+-----------------+-------------------+
   +-------------+---------------+------------------+------------------+
   | 0           | Reserved      | This document    |                  |
   | 1-4         | EQ            | EQ               | EQ               |
   | 5-31739     | Unassigned    |                  |                  |
   | 31740-31743 | Experimental  | This Document    | Reserved, not to |
   |             | Use           |                  | be assigned      |
   | 31744-64507 | Unassigned    |                  |                  |
   | 64508-64511 | Experimental  | This document    | Resereved, Reserved, not to |
   |             | Use           |                  | be assigned      |
   | 64512-65535 | Unassigned    |                  |                  |
   +-------------+---------------+-----------------+-------------------+
   +-------------+---------------+------------------+------------------+

                 Table 15: 16: Sub-TLVs for TLV 11 Assignments

6.2.5.  Updates to the registry for SubTLVs Sub-TLVs for TLV 20

   This section describes the new registration procedures and the
   assignments for the "Sub-TLVs for TLV Type 20" [IANA-Sub-20] sub-
   registry based on the new registration procedures.

   o  The "Specification Required" registration procedure has been
      changed to "RFC Required", the comment "Experimental RFC Required"
      has been removed.

   o  The code points registration procedure "Vendor Private Use" has
      been removed and replaced with "First Come, First Served" code
      points.

   o  Two small sets, 4 code points each, has ve been created for Experimental Use.

   o  Code points that are reserved are clearly marked as such.

   o  The assignments have been updated to match the new registration
      procedures.

   o  The notes related to the registration procedures have been changed
      to reflect when a response is required if a sub-TLV is not
      recognized or not.

   The registration procedures for the "Sub-TLVs for TLV Type 20"
   [IANA-Sub-20] sub-registry will now look like this:

   +-------------+-------------------+---------------------------------+
   | Range       | Registration      | Note                            |
   |             | Procedures        |                                 |
   +-------------+-------------------+---------------------------------+
   | 0-16383     | Standards Action  | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | section 3.1]                    |
   | 16384-31739 | RFC Required      | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             | 37140-37144                   | section 3.1]                    |
   | 31740-31743 | Experimental Use  | Reserved, not to be assigned    |
   | 31748-32767 31744-32767 | FCFS              | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | section 3.1]                    |
   | 32768-49161 | Standards Action  | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   | 49162-64507 | RFC Required      | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   | 64508-64511 | Experimental Use  | Reserved, not to be assigned    |
   | 64512-65535 | FCFS              | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   +-------------+-------------------+---------------------------------+

        Table 16: 17: Registration Procedures for Sub-TLVs for TLVs 20

   +-------------+---------------+-----------------+-------------------+

   +-------------+---------------+------------------+------------------+
   | Type        | TLV Name      | Reference        | Comment          |
   +-------------+---------------+-----------------+-------------------+
   +-------------+---------------+------------------+------------------+
   | 0           | Reserved      | This document    |                  |
   | 1-5         | EQ            | EQ               | EQ               |
   | 6-31739     | Unassigned    |                  |                  |
   | 31740-31743 | Experimental  | This Document    | Reserved, not to |
   |             | Use           |                  | be assigned      |
   | 31744-64507 | Unassigned    |                  |                  |
   | 64508-64511 | Experimental  | This document    | Resereved, Reserved, not to |
   |             | Use           |                  | be assigned      |
   | 64512-65535 | Unassigned    |                  |                  |
   +-------------+---------------+-----------------+-------------------+
   +-------------+---------------+------------------+------------------+

                 Table 17: 18: Sub-TLVs for TLV 20 Assignments

6.2.6.  Updates to the registry for SubTLVs for TLV 23

   This section describes the new registration procedures and the
   assignments for the "Sub-TLVs for TLV Type 23" [IANA-Sub-23] sub-
   registry based on the new registration procedures.

   o  The "Specification Required" registration procedure has been
      changed to "RFC Required", the comment "Experimental RFC Required"
      has been removed.

   o  The code points registration procedure "Vendor Private Use" has
      been removed and replaced with "First Come, First Served" code
      points.

   o  Two small sets, 4 code points each, has have been created for
      Experimental Use.

   o  Code points that are reserved are clearly marked as such.

   o  The assignments have been updated to match the new registration
      procedures.

   o  The notes related to the registration procedures have been changed
      to reflect when a response is required if a sub-TLV is not
      recognized or not.

   The registration procedures for the "Sub-TLVs for TLV Type 23"
   [IANA-Sub-23] sub-registry will now look like this:

   +-------------+-------------------+---------------------------------+
   | Range       | Registration      | Note                            |
   |             | Procedures        |                                 |
   +-------------+-------------------+---------------------------------+
   | 0-16383     | Standards Action  | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | section 3.1]                    |
   | 16384-31739 | RFC Required      | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   | 37140-37144             |                   | section 3.1]                    |
   | 31740-31743 | Experimental Use  | Reserved, not to be assigned    |
   | 31748-32767 31744-32767 | FCFS              | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | section 3.1]                    |
   | 32768-49161 | Standards Action  | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   | 49162-64507 | RFC Required      | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   | 64508-64511 | Experimental Use  | Reserved, not to be assigned    |
   | 64512-65535 | FCFS              | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   +-------------+-------------------+---------------------------------+

        Table 18: 19: Registration Procedures for Sub-TLVs for TLVs 23

   +-------------+---------------+-----------------+-------------------+

   +-------------+---------------+------------------+------------------+
   | Type        | TLV Name      | Reference        | Comment          |
   +-------------+---------------+-----------------+-------------------+
   +-------------+---------------+------------------+------------------+
   | 0           | Reserved      | [RFC7555]        |                  |
   | 1           | EQ            | EQ               | EQ               |
   | 2-31739     | Unassigned    |                  |                  |
   | 31740-31743 | Experimental  | This Document    | Reserved, not to |
   |             | Use           |                  | be assigned      |
   | 31744-64507 | Unassigned    |                  |                  |
   | 64508-64511 | Experimental  | This document    | Resereved, Reserved, not to |
   |             | Use           |                  | be assigned      |
   | 64512-65535 | Unassigned    |                  |                  |
   +-------------+---------------+-----------------+-------------------+
   +-------------+---------------+------------------+------------------+

                 Table 19: 20: Sub-TLVs for TLV 23 Assignments

6.2.7.  Updates to the registry for SubTLVs for TLV 27

   This section describes the new registration procedures and the
   assignments for the "Sub-TLVs for TLV Type 27" [IANA-Sub-27] sub-
   registry based on the new registration procedures.

   o  The "Specification Required" registration procedure has been
      changed to "RFC Required", the comment "Experimental RFC Required"
      has been removed.

   o  The code points registration procedure "Vendor Private Use" has
      been removed and replaced with "First Come, First Served" code
      points.

   o  Two small sets, 4 code points each, has have been created for
      Experimental Use.

   o  Code points that are reserved are clearly marked as such.

   o  The assignments have been updated to match the new registration
      procedures.

   o  The notes related to the registration procedures have been changed
      to reflect when a response is required if a sub-TLV is not
      recognized or not.

   The registration procedures for the "Sub-TLVs for TLV Type 27"
   [IANA-Sub-27] sub-registry will now look like this:

   +-------------+-------------------+---------------------------------+
   | Range       | Registration      | Note                            |
   |             | Procedures        |                                 |
   +-------------+-------------------+---------------------------------+
   | 0-16383     | Standards Action  | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | section 3.1]                    |
   | 16384-31739 | RFC Required      | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | section 3.1]                    |
   | 37140-37144 31740-31743 | Experimental Use  | Reserved, not to be assigned    |
   | 31748-32767 31744-32767 | FCFS              | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | require an error message if not |
   |             |                   | recognized. [This document,     |
   |             |                   | section 3.1]                    |
   | 32768-49161 | Standards Action  | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   | 49162-64507 | RFC Required      | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   | 64508-64511 | Experimental Use  | Reserved, not to be assigned    |
   | 64512-65535 | FCFS              | This range is for Sub-TLVs sun-TLVs that |
   |             |                   | can be silently dropped if not  |
   |             |                   | recognized.                     |
   +-------------+-------------------+---------------------------------+

         Table 20: 21: Registration Procedures for Sub-TLVs for TLV 27

   +-------------+---------------+-----------------+-------------------+

   +-------------+---------------+------------------+------------------+
   | Type        | TLV Name      | Reference        | Comment          |
   +-------------+---------------+-----------------+-------------------+
   +-------------+---------------+------------------+------------------+
   | 0           | Reserved      | [RFC7555]        |                  |
   | 1           | EQ            | EQ               | EQ               |
   | 2-31739     | Unassigned    |                  |                  |
   | 31740-31743 | Experimental  | This Document    | Reserved, not to |
   |             | Use           |                  | be assigned      |
   | 31744-64507 | Unassigned    |                  |                  |
   | 64508-64511 | Experimental  | This document    | Resereved, Reserved, not to |
   |             | Use           |                  | be assigned      |
   | 64512-65535 | Unassigned    |                  |                  |
   +-------------+---------------+-----------------+-------------------+
   +-------------+---------------+------------------+------------------+

                 Table 21: 22: Sub-TLVs for TLV 27 Assignments

7.  Acknowledgements

   The authors wish to thank Adrian Farrel, who both made very useful
   comments and agreed to serve as the document shepherd.

   The authors also wish to thank Micelle Cotton who very patiently
   worked with us to determine how our registries could and should be
   updated.

   The authors thanks Donald Eastlake for a careful and detailed review.

8.  References

8.1.  Normative References

   [IANA-LSP-PING]
              "Multiprotocol Label Switching (MPLS) Label Switched Paths
              (LSPs) Ping Parameters",
              <https://www.iana.org/assignments/mpls-lsp-ping-
              parameters/mpls-lsp-ping-parameters.xhtml/>.

   [IANA-MT]  "Message Types", <https://www.iana.org/assignments/mpls-
              lsp-ping-parameters/mpls-lsp-ping-
              parameters.xhtml#message-types>.

   [IANA-RC]  "Return Codes", <https://www.iana.org/assignments/mpls-
              lsp-ping-parameters/#return-codes>.

   [IANA-RM]  "Reply Modes", <https://www.iana.org/assignments/mpls-lsp-
              ping-parameters/#reply-modes>.

   [IANA-Sub-1-16-21]
              "Sub-TLVs for TLV Types 1, 16, and 21",
              <https://www.iana.org/assignments/https://www.iana.org/
              assignments/mpls-lsp-ping-parameters/mpls-lsp-ping-
              parameters.xhtml#sub-tlv-1-16-21>.

   [IANA-Sub-11]
              "Sub-TLVs for TLV Type 11",
              <https://www.iana.org/assignments/mpls-lsp-ping-
              parameters/mpls-lsp-ping-parameters/mpls-lsp-ping-
              parameters.xhtml#sub-tlv-11>.

   [IANA-Sub-20]
              "Sub-TLVs for TLV Type 20",
              <https://www.iana.org/assignments/mpls-lsp-ping-
              parameters/mpls-lsp-ping-parameters/mpls-lsp-ping-
              parameters.xhtml#sub-tlv-20>.

   [IANA-Sub-23]
              "Sub-TLVs for TLV Type 23",
              <https://www.iana.org/assignments/mpls-lsp-ping-
              parameters/mpls-lsp-ping-parameters/mpls-lsp-ping-
              parameters.xhtml#sub-tlv-23>.

   [IANA-Sub-27]
              "Sub-TLVs for TLV Type 27",
              <https://www.iana.org/assignments/mpls-lsp-ping-
              parameters/mpls-lsp-ping-parameters/mpls-lsp-ping-
              parameters.xhtml#sub-tlv-27>.

   [IANA-Sub-6]
              "Sub-TLVs for TLV Type 6",
              <https://www.iana.org/assignments/mpls-lsp-ping-
              parameters/mpls-lsp-ping-parameters/mpls-lsp-ping-
              parameters.xhtml#sub-tlv-6>.

   [IANA-TLV-reg]
              "TLVs", <https://www.iana.org/assignments/mpls-lsp-ping-
              parameters/mpls-lsp-ping-parameters.xhtml#tlvs>.

   [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>.

   [RFC8029]  Kompella, K., Swallow, G., Pignataro, C., Ed., Kumar, N.,
              Aldrin, S., and M. Chen, "Detecting Multiprotocol Label
              Switched (MPLS) Data-Plane Failures", RFC 8029,
              DOI 10.17487/RFC8029, March 2017,
              <https://www.rfc-editor.org/info/rfc8029>.

   [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>.

   [RFC8287]  Kumar, N., Ed., Pignataro, C., Ed., Swallow, G., Akiya,
              N., Kini, S., and M. Chen, "Label Switched Path (LSP)
              Ping/Traceroute for Segment Routing (SR) IGP-Prefix and
              IGP-Adjacency Segment Identifiers (SIDs) with MPLS Data
              Planes", RFC 8287, DOI 10.17487/RFC8287, December 2017,
              <https://www.rfc-editor.org/info/rfc8287>.

   [RFC8611]  Akiya, N., Swallow, G., Litkowski, S., Decraene, B.,
              Drake, J., and M. Chen, "Label Switched Path (LSP) Ping
              and Traceroute Multipath Support for Link Aggregation
              Group (LAG) Interfaces", RFC 8611, DOI 10.17487/RFC8611,
              June 2019, <https://www.rfc-editor.org/info/rfc8611>.

8.2.  Informative References

   [IANA-Sub-9]
              "Sub-TLVs for TLV Type 9",
              <https://www.iana.org/assignments/mpls-lsp-ping-
              parameters/mpls-lsp-ping-parameters/mpls-lsp-ping-
              parameters.xhtml#sub-tlv-9>.

   [lsp-ping-NameSpace]
              "Multiprotocol Label Switching (MPLS) Label Switched Paths
              (LSPs) Ping Parameters",
              <https://www.iana.org/assignments/mpls-lsp-ping-
              parameters/mpls-lsp-ping-parameters.xhtml>.

   [RFC7110]  Chen, M., Cao, W., Ning, S., Jounay, F., and S. Delord,
              "Return Path Specified Label Switched Path (LSP) Ping",
              RFC 7110, DOI 10.17487/RFC7110, January 2014,
              <https://www.rfc-editor.org/info/rfc7110>.

   [RFC7555]  Swallow, G., Lim, V., and S. Aldrin, "Proxy MPLS Echo
              Request", RFC 7555, DOI 10.17487/RFC7555, June 2015,
              <https://www.rfc-editor.org/info/rfc7555>.

   [RFC7743]  Luo, J., Ed., Jin, L., Ed., Nadeau, T., Ed., and G.
              Swallow, Ed., "Relayed Echo Reply Mechanism for Label
              Switched Path (LSP) Ping", RFC 7743, DOI 10.17487/RFC7743,
              January 2016, <https://www.rfc-editor.org/info/rfc7743>.

   [RFC7759]  Bellagamba, E., Mirsky, G., Andersson, L., Skoldstrom, P.,
              Ward, D., and J. Drake, "Configuration of Proactive
              Operations, Administration, and Maintenance (OAM)
              Functions for MPLS-Based Transport Networks Using Label
              Switched Path (LSP) Ping", RFC 7759, DOI 10.17487/RFC7759,
              February 2016, <https://www.rfc-editor.org/info/rfc7759>.

   [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", BCP 26,
              RFC 8126, DOI 10.17487/RFC8126, June 2017,
              <https://www.rfc-editor.org/info/rfc8126>.

Authors' Addresses

   Loa Andersson
   Bronze Dragon Consulting

   Email: loa@pi.nu

   Mach Chen
   Huawei Techologies

   Email: mach.chen@huawei.com

   Carlos Pignataro
   Cisco Systems

   Email: cpignata@cisco.com

   Tarek Saad
   Juniper Networks

   Email: tsaad@juniper.net