LSP Ping/Traceroute for Enabled In-situ OAM Capabilities
draft-xiao-mpls-lsp-ping-ioam-conf-state-01

MPLS Working Group                                                X. Min
Internet-Draft                                                 ZTE Corp.
Intended status: Standards Track                               G. Mirsky
Expires: 24 October 2023                                        Ericsson
                                                           22 April 2023

        LSP Ping/Traceroute for Enabled In-situ OAM Capabilities
              draft-xiao-mpls-lsp-ping-ioam-conf-state-01

Abstract

   This document describes the MPLS Node IOAM Information Query
   functionality, which uses the MPLS echo request/reply messages,
   allowing the IOAM encapsulating node to discover the enabled IOAM
   capabilities of each IOAM transit and decapsulating node.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions Used in This Document . . . . . . . . . . . . . .   3
   3.  IOAM Capabilities Query TLV . . . . . . . . . . . . . . . . .   3
   4.  IOAM Capabilities Response TLV  . . . . . . . . . . . . . . .   3
     4.1.  IOAM Capabilities Sub-TLVs  . . . . . . . . . . . . . . .   4
     4.2.  Examples of IOAM Capabilities Response TLV  . . . . . . .   5
   5.  Return Code Field Processing  . . . . . . . . . . . . . . . .   7
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
     6.1.  TLV and Sub-TLV Allocation  . . . . . . . . . . . . . . .   7
     6.2.  OAM Configuration Errors  . . . . . . . . . . . . . . . .   8
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .   9
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   9
   9.  Normative References  . . . . . . . . . . . . . . . . . . . .   9
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  10

1.  Introduction

   As specified in [RFC9359], echo request/reply can be used by the In-
   situ OAM (IOAM) encapsulating node to discover the enabled IOAM
   capabilities at IOAM transit and decapsulating nodes.

   [RFC8029] defines a probe message called "MPLS echo request", and a
   response message called "MPLS echo reply" for returning the result of
   the probe.

   This document describes the MPLS Node IOAM Information Query
   functionality, which uses the MPLS echo request/reply messages,
   allowing the IOAM encapsulating node to discover the enabled IOAM
   capabilities of each IOAM transit and decapsulating node.

   [RFC8029] specifies "ping" and "traceroute" modes.  In "ping" mode,
   the ingress LSR sends a single MPLS echo request with the TTL in the
   outermost label set to 255.  The MPLS echo request is intended to
   reach the end of the path and only the egress LSR is expected to
   respond with the MPLS echo reply.  In "traceroute" mode, the ingress
   LSR transmits a sequence of MPLS echo requests with the TTL value
   being set in successive probe packets to 1, 2, and so on.  Using TTL
   expiration as the exception mechanism, each LSR is expected to
   respond by transmitting an MPLS echo reply.

   In an MPLS network, the ingress LSR may also act as the IOAM
   encapsulating node.  In such a case, a transit LSR acts as the IOAM
   transit node, and the egress LSR acts as the IOAM decapsulating node.
   Usually, the trace option of IOAM data is needed, the IOAM
   encapsulating node requires to query the enabled IOAM capabilities of
   each IOAM transit and decapsulating node, then the "traceroute" mode

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   can be used.  In case that only the edge to edge option of IOAM data
   is needed, the IOAM encapsulating node requires to query the enabled
   IOAM Capabilities of only the IOAM decapsulating node, then the
   "ping" mode can be used.

   Note that in the current document only p2p MPLS LSP is taken into
   account, and p2mp MPLS LSP is for further study.

2.  Conventions Used in This Document

   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.  IOAM Capabilities Query TLV

   The IOAM Capabilities Query TLV presented in Figure 1 is carried as a
   TLV of the MPLS Echo Request message:

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  IOAM Capa. Query Type (TBA1) |            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     .           IOAM Capabilities Query Container Payload           .
     .                        as specified in                        .
     .                    Section 3.1 of RFC9359                     .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                   Figure 1: IOAM Capabilities Query TLV

   Type: Indicates the IOAM Capabilities Query TLV.  The value is TBA1.

   Length: The length of the TLV's Value field in octets.

   The Value field is a List of IOAM Namespace-IDs, which is also called
   IOAM Capabilities Query Container Payload in Section 3.1 of
   [RFC9359].

4.  IOAM Capabilities Response TLV

   The IOAM Capabilities Response TLV presented in Figure 2 is carried
   as a TLV of the MPLS Echo Reply message:

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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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |IOAM Capa. Response Type (TBA2)|            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     .         IOAM Capabilities Response Container Payload          .
     .                        as specified in                        .
     .                    Section 3.2 of RFC9359                     .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                  Figure 2: IOAM Capabilities Response TLV

   Type: Indicates the IOAM Capabilities Response TLV.  The value is
   TBA2.

   Length: The length of the TLV's Value field in octets.

   The Value field is a List of IOAM Capabilities Objects, which is also
   called IOAM Capabilities Response Container Payload in Section 3.2 of
   [RFC9359].  Each IOAM Capabilities Object is encoded in a sub-TLV
   format.

4.1.  IOAM Capabilities Sub-TLVs

   All IOAM Capabilities sub-TLVs (aka Objects) are encapsulated in an
   IOAM Capabilities Response TLV of an MPLS Echo Reply message.

   Each IOAM Capabilities sub-TLV has the following format:

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   IOAM Capa. Sub-type (TBA)   |            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     .                IOAM Capabilities Object Payload               .
     .                        as specified in                        .
     .                   Section 3.2.x of RFC9359                    .
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                    Figure 3: IOAM Capabilities Sub-TLV

   Sub-type: Indicates the IOAM Capabilities sub-TLVs.  The values are
   listed as the following:

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      Value         Sub-type Name
      -----         -----------
      TBA3          IOAM Pre-allocated Tracing Capabilities Object
      TBA4          IOAM Incremental Tracing Capabilities Object
      TBA5          IOAM Proof of Transit Capabilities Object
      TBA6          IOAM Edge-to-Edge Capabilities Object
      TBA7          IOAM DEX Capabilities Object
      TBA8          IOAM End-of-Domain Object

   Length: The length of the sub-TLV's Value field in octets.

   The Value field is the IOAM Capabilities Object Payload, which is
   defined respectively in Section 3.2.1, Section 3.2.2, Section 3.2.3,
   Section 3.2.4, Section 3.2.5 and Section 3.2.6 of [RFC9359].

4.2.  Examples of IOAM Capabilities Response TLV

   In a deployment where only the default Namespace-ID is used, the IOAM
   Pre-allocated Tracing Capabilities and IOAM Proof of Transit
   Capabilities are enabled at an IOAM transit node, if that IOAM
   transit node received an MPLS echo request containing IOAM
   Capabilities Query TLV, then the IOAM Capabilities Response TLV
   contained in an MPLS echo reply is depicted as the following:

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |IOAM Capa. Response Type (TBA2)|            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   IOAM Capa. Sub-type (TBA3)  |            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |               IOAM-Trace-Type                 |  Reserved   |W|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |         Namespace-ID          |          Ingress_MTU          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  Ingress_if_id (short or wide format)         ......          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   IOAM Capa. Sub-type (TBA5)  |            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |         Namespace-ID          | IOAM-POT-Type |SoP| Reserved  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

           Figure 4: Example 1 of IOAM Capabilities Response TLV

   In a deployment where two Namespace-IDs (Namespace-ID1 and Namespace-
   ID2) are used, for both Namespace-ID1 and Namespace-ID2 the IOAM Pre-
   allocated Tracing Capabilities and IOAM Proof of Transit Capabilities
   are enabled at an IOAM transit node, if that IOAM transit node

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   received an MPLS echo request containing IOAM Capabilities Query TLV,
   then the IOAM Capabilities Response TLV contained in an MPLS echo
   reply is depicted as the following:

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |IOAM Capa. Response Type (TBA2)|            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   IOAM Capa. Sub-type (TBA3)  |            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |               IOAM-Trace-Type                 |  Reserved   |W|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |         Namespace-ID1         |          Ingress_MTU          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  Ingress_if_id (short or wide format)         ......          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   IOAM Capa. Sub-type (TBA5)  |            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |         Namespace-ID1         | IOAM-POT-Type |SoP| Reserved  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   IOAM Capa. Sub-type (TBA3)  |            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |               IOAM-Trace-Type                 |  Reserved   |W|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |         Namespace-ID2         |          Ingress_MTU          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  Ingress_if_id (short or wide format)         ......          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   IOAM Capa. Sub-type (TBA5)  |            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |         Namespace-ID2         | IOAM-POT-Type |SoP| Reserved  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

           Figure 5: Example 2 of IOAM Capabilities Response TLV

   Note that multiple sub-TLVs with the same sub-type may be present in
   an IOAM Capabilities Response TLV, as long as the Namespace-IDs in
   these sub-TLVs are all different.

   In a deployment where only the default Namespace-ID is used, the IOAM
   Pre-allocated Tracing Capabilities, IOAM Proof of Transit
   Capabilities and IOAM Edge-to-Edge Capabilities are enabled at the
   IOAM decapsulating node, if that IOAM decapsulating node received an
   MPLS echo request containing IOAM Capabilities Query TLV, then the
   IOAM Capabilities Response TLV contained in an MPLS echo reply is
   depicted as the following:

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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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |IOAM Capa. Response Type (TBA2)|            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   IOAM Capa. Sub-type (TBA3)  |            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |               IOAM-Trace-Type                 |  Reserved   |W|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |         Namespace-ID          |          Ingress_MTU          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  Ingress_if_id (short or wide format)         ......          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   IOAM Capa. Sub-type (TBA5)  |            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |         Namespace-ID          | IOAM-POT-Type |SoP| Reserved  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   IOAM Capa. Sub-type (TBA6)  |            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |         Namespace-ID          |         IOAM-E2E-Type         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |TSF|         Reserved          |           Reserved            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

           Figure 6: Example 3 of IOAM Capabilities Response TLV

5.  Return Code Field Processing

   The Return Code field in the MPLS echo reply MUST be set to (TBA9) No
   Matched Namespace-ID if any of the following conditions apply:

   *  The IOAM Capabilities Query TLV does not include any Namespace-ID.

   *  None of the contained list of IOAM Namespace-IDs is recognized.

   *  None of the contained list of IOAM Namespace-IDs is enabled.

6.  IANA Considerations

6.1.  TLV and Sub-TLV Allocation

   IANA maintains the "Multiprotocol Label Switching (MPLS) Label
   Switched Paths (LSPs) Ping Parameters" registry, and within that
   registry a sub-registry for TLVs and sub-TLVs.

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   IANA is requested to allocate a new IOAM Capabilities Query TLV (Type
   TBA1) and a new IOAM Capabilities Response TLV (Type TBA2) from the
   Standards Action range (0-16383), and sub-TLVs as follows from sub-
   registry presented in Table 1, called "Sub-TLVs for TLV Type TBA2".

   Registration procedures for Sub-TLVs from ranges 0-16383 and
   32768-49161 are by Standards Action.  Ranges 16384-31739 and
   49162-64507 are through RFC Required.

     +======+==========+============================+===============+
     | Type | Sub-type | Value Field                | Reference     |
     +======+==========+============================+===============+
     | TBA1 |          | IOAM Capabilities Query    | This document |
     +------+----------+----------------------------+---------------+
     | TBA2 |          | IOAM Capabilities Response | This document |
     +------+----------+----------------------------+---------------+
     |      | TBA3     | IOAM Pre-allocated Tracing | This document |
     |      |          | Capabilities Object        |               |
     +------+----------+----------------------------+---------------+
     |      | TBA4     | IOAM Incremental Tracing   | This document |
     |      |          | Capabilities Object        |               |
     +------+----------+----------------------------+---------------+
     |      | TBA5     | IOAM Proof of Transit      | This document |
     |      |          | Capabilities Object        |               |
     +------+----------+----------------------------+---------------+
     |      | TBA6     | IOAM Edge-to-Edge          | This document |
     |      |          | Capabilities Object        |               |
     +------+----------+----------------------------+---------------+
     |      | TBA7     | IOAM DEX Capabilities      | This document |
     |      |          | Object                     |               |
     +------+----------+----------------------------+---------------+
     |      | TBA8     | IOAM End-of-Domain Object  | This document |
     +------+----------+----------------------------+---------------+

                    Table 1: IANA TLV Type Allocation

6.2.  OAM Configuration Errors

   IANA maintains the "Multiprotocol Label Switching (MPLS) Label
   Switched Paths (LSPs) Ping Parameters" registry, and within that
   registry a sub-registry "Return Codes".

   IANA is requested to assign a new Return Code from the Standards
   Action range (0-191) as follows:

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      +==================+=========================+===============+
      | Error Value Code | Description             | Reference     |
      +==================+=========================+===============+
      | TBA9             | No Matched Namespace-ID | This document |
      +------------------+-------------------------+---------------+

                   Table 2: IANA Return Code Allocation

7.  Security Considerations

   Securiy issues discussed in [RFC8029] and [RFC9359] apply to this
   document.

   This document recommends that the network operators establish
   policies that restrict access to MPLS Node IOAM Information Query
   functionality.  In order to enforce these policies, nodes that
   support MPLS Node IOAM Information Query functionality SHOULD support
   the following configuration options:

   *  Enable/disable MPLS Node IOAM Information Query functionality.  By
      default, MPLS Node IOAM Information Query functionality is
      disabled.

   *  Define enabled Namespace-IDs.  By default, all Namespace-IDs
      except the default one (i.e., Namespace-ID 0x0000) are disabled.

8.  Acknowledgements

   To be added.

9.  Normative References

   [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>.

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   [RFC9359]  Min, X., Mirsky, G., and L. Bo, "Echo Request/Reply for
              Enabled In Situ OAM (IOAM) Capabilities", RFC 9359,
              DOI 10.17487/RFC9359, April 2023,
              <https://www.rfc-editor.org/info/rfc9359>.

Authors' Addresses

   Xiao Min
   ZTE Corp.
   Nanjing
   China
   Phone: +86 25 88013062
   Email: xiao.min2@zte.com.cn

   Greg Mirsky
   Ericsson
   United States of America
   Email: gregimirsky@gmail.com

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