MPLS Working Group                                              L. Gong
Internet Draft                                             China Mobile
Intended status: Standards Track                                 C. Lin
Expires: January 09, 2024                          New H3C Technologies
                                                          July 07, 2025


        Operations, Administration and Maintenance (OAM) for Network
                 Resource Partition (NRP) in MPLS Network



                      draft-gong-mpls-nrp-oam-mpls-00


Abstract

   A Network Resource Partition (NRP) represents a subset of network
   resources and associated policies within the underlay network.

   This document describes the implementation of the Operations,
   Administration, and Maintenance (OAM) mechanism for NRPs in MPLS
   networks. By extending existing OAM mechanisms such as ping,
   traceroute, the proposed solution enables comprehensive NRP support
   in MPLS networks.

Status of this Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF). Note that other groups may also distribute
   working documents as Internet-Drafts. The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six
   months and may be updated, replaced, or obsoleted by other documents
   at any time. It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on January 09, 2024.

Copyright Notice

   Copyright (c) 2025 IETF Trust and the persons identified as the
   document authors. All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of

Gong & Lin, et al.     Expire January 09, 2024                [Page 1]

Internet-Draft         OAM for NRP in MPLS Network           July 2025


   publication of this document. Please review these documents
   carefully, as they describe your rights and restrictions with
   respect to this document. Code Components extracted from this
   document must include Simplified BSD License text as described in
   Section 4.e of the Trust Legal Provisions and are provided without
   warranty as described in the Simplified BSD License.

Table of Contents


   1. Introduction...................................................2
      1.1. Requirements Language.....................................3
   2. OAM Mechanisms.................................................3
   3. MPLS PING......................................................3
   4. MPLS TRACEROUTE................................................4
   5. UseCase........................................................6
      5.1. MPLS PING.................................................6
      5.2. MPLS TRACEROUTE...........................................7
   6. Security Considerations........................................7
   7. IANA Considerations............................................8
      7.1. MPLS Reply Error Code.....................................8
   8. References.....................................................8
      8.1. Normative References......................................8
      8.2. Informative References....................................8
   Acknowledgements..................................................8
   Authors' Addresses................................................9

   1. Introduction

   [RFC9543] provides the definition of IETF network slice for use
   within the IETF and discusses the general framework for requesting
   and operating IETF Network Slices, their characteristics, and the
   necessary system components and interfaces. It also introduces the
   concept Network Resource Partition (NRP), which is a subset of the
   resources and associated policies in the underlay network.

   Using OAM tools enables real-time monitoring of the operational
   status of network slices, allowing for quick detection and
   localization of faults. When a node or link within a network slice
   experiences a failure, OAM tools can promptly issue alerts,
   assisting network administrators in taking swift corrective action
   to minimize service downtime. Therefore, the use of OAM tools in an
   NRP network is crucial for ensuring the availability and performance
   of network slice resources. This not only enhances user experience
   but also improves the overall efficiency and stability of the
   network.



Gong & Lin, et al.    Expires January 09, 2024                [Page 2]

Internet-Draft         OAM for NRP in MPLS Network           July 2025


   Existing OAM tools typically include Ping, Traceroute. [RFC8029]
   describes how to Detect MPLS Data-Plane Failures in MPLS networks.

   This document continues to employ these existing OAM mechanisms to
   monitor Data-Plane NRP resources Failures.

1.1. Requirements Language

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



   2. OAM Mechanisms

   [RFC8029] describes how to Detect MPLS Data-Plane Failures in MPLS
   networks.

   During the process of using existing OAM mechanisms to check the
   operational status of NRP resources, the OAM initiator needs to
   carry the NRP-ID in the data plane of the inspection packets.

   Intermediate equipment and OAM End Points need to check the
   availability of NRP resources when receiving OAM packets with an
   NRP-ID. If the NRP resources are unavailable, they should respond to
   the OAM initiator with an error message, indicating that the NRP
   resources are unavailable.

   This document adopts these existing methods of carrying the NRP-ID
   in the data plane to perform OAM operations within NRP networks. The
   specific mechanisms for carrying the NRP-ID in the data plane are
   outside the scope of this document. Based on different underlying
   networks, this document describes how to use OAM tools to monitor
   NRP resources by carrying the NRP-ID during OAM operations.

   Building on the aforementioned aspects, using existing OAM
   mechanisms for underlay network operations and existing mechanisms
   for carrying the NRP-ID in the data plane, this document will
   describe how to use OAM tools to monitor the operational status of
   NRP resources within NRP networks.

   3. MPLS PING

   When performing a MPLS PING operation, the initiator sends a MPLS
   Echo request. To support the probing of NRP resources, NRP

Gong & Lin, et al.    Expires January 09, 2024                [Page 3]

Internet-Draft         OAM for NRP in MPLS Network           July 2025


   information is carried in the data layer. Intermediate nodes inspect
   the NRP resources. If the request packet can be forwarded to the
   control plane, the response packet can include an error code to
   notify the initiator of an "NRP resource unavailable" error.
   However, if the packet cannot be forwarded to the control plane, the
   request packet is simply dropped, and the initiator cannot obtain
   specific error information.

   1)MPLS Echo Request with NRP
   --------------------->
              2) Check NRP Not Available
                 MPLS Echo Reply Reponse Error
   <-----------

                        3) MPLS Echo Reply
   <----------------------
   +--+      +--+      +--+
   |N1+------|N2+------|N3+
   +--+      +--+      +--+
           Figure 1 MPLS PING for NRP


   Process of MPLS PING for NRP:

   1)           The initiator of the MPLS Echo Request includes the NRP-ID in the
      data layer when sending the MPLS PING request.

   2)           The intermediate node or End Point first checks if the NRP
      resources are available when processing a MPLS Echo Request. If
      they are not available, it responds with a MPLS Echo Reply,
      indicating the Error as "NRP resources unavailable".

      For MPLS networks, it is necessary to extend the Return Codes
      carried in the MPLS Echo Reply(IANA 8.1).

   3)           If the check passes, the End Point will respond with a normal MPLS
      Echo Reply.

   4. MPLS TRACEROUTE

   When performing a MPLS TRACEROUTE operation, the TRACEROUTE
   initiator sends MPLS Echo request packets toward the destination
   node by incrementally increasing the TTL value. To support the
   probing of NRP resources, NRP information is carried in the data
   layer. Each intermediate node first checks the availability of NRP
   resources before inspecting the TTL. If the resources are
   unavailable, the node responds with an MPLS Echo Reply with error
   message indicating NRP resource unavailability. The packets used for

Gong & Lin, et al.    Expires January 09, 2024                [Page 4]

Internet-Draft         OAM for NRP in MPLS Network           July 2025


   MPLS TRACEROUTE are the same as those used for MPLS PING. When NRP
   resources are unavailable, the error codes used are also identical
   to those used in MPLS PING operations

   1)           MPLS Echo Request with NRP-ID
   ------------>
              2) MPLS Echo Reply
   <-----------
   3) MPLS Echo Request with NRP-ID
   --------------------->

                       4) MPLS Echo Reply
   <--------------------
   +--+      +--+      +--+
   |N1+------|N2+------|N3+
   +--+      +--+      +--+
           Figure 2 MPLS Traceroute for NRP


   Process of MPLS Traceroute for NRP:

   1)           The initiator of the MPLS Echo request includes the NRP-ID in the
      data layer when sending the Traceroute request.

      The MPLS Echo Request with TTL 1 to n increase.

   2)           The intermediate node or End Point first checks if the NRP
      resources are available when processing a MPLS Echo Request. If
      they are not available, it responds with a MPLS Echo Reply,
      indicating the Error as "NRP resources unavailable". The error
      code for expansion should be the same as MPLS PING.

   3)           If the check passes, the process proceeds with a normal MPLS
      Traceroute, performing hop-by-hop detection of the path to the End
      Point until the Traceroute process is completed, and the detection
      results are outputted.












Gong & Lin, et al.    Expires January 09, 2024                [Page 5]

Internet-Draft         OAM for NRP in MPLS Network           July 2025


   5. UseCase

   +-------------------------| N100 |--------------------------------+
   |                                                                 |
   |  ======NRP-1===== NRP-1 ------ NRP-1======NRP-1-----   ======   |
      ||N1||-----||N2||------| N3 |------||N4||-----| N5 |---||N7||
      ||  ||-----||  ||------|    |------||  ||-----|    |---||  ||
      ======NRP-2===== NRP-2 ------ NRP-2======NRP-2------   ======
         |            |                      |                  |
      ---+--          | NRP-1 ------ NRP-1   |                --+---
      |CE 1|          +-------| N6 |---------+                |CE 2|
      ------            NRP-2 |    | NRP-2                    ------
                              ------
                                 Figure 5 NRP network diagram


   As illustrated In the reference topology of Figure 1,

   Node j has a IPv4 loopback address 192.168.j.1/32

   A LABEL at node j is 1j000.

   Node N100 is a controller.



5.1. MPLS PING

   An example of MPLS Ping success:

    > ping 15000 via label-stack 12000, 14000, NRP-ID: 1, Ret NRP-ID: 2

    Sending 5, 100-byte MPLS Echos to 192.168.5.2, timeout is 2 seconds:

    !!!!!

    Success rate is 100 percent (5/5), round-trip min/avg/max = 0.625
   /0.749/0.931 ms



   An example of MPLS Ping failure due to NRP resource unavailability:

    > ping 15000 via label-stack 12000, 14000, NRP-ID: 1, Ret NRP-ID: 2

   Reply to request 2 (1 ms). Return Code: 'N'

   Reply to request 3 (1 ms). Return Code: 'N'

Gong & Lin, et al.    Expires January 09, 2024                [Page 6]

Internet-Draft         OAM for NRP in MPLS Network           July 2025


   Reply to request 4 (1 ms). Return Code: 'N'

   Reply to request 3 (1 ms). Return Code: 'N'

   Reply to request 4 (1 ms). Return Code: 'N'

   Success rate is 0 percent (0/5), round-trip min/avg/max = 1/1/1 ms



   Error code 'N' indicates that the cause of the error is the
   unavailability of NRP resources. This explanation applies to the
   following examples as well and will not be reiterated.

5.2. MPLS TRACEROUTE

   An example of MPLS traceroute success:

   > traceroute 15000 via label-stack 12000, 14000, NRP-ID: 1, Ret-NRP-
   ID: 2

   Tracing the route to 15000

   1  192.168.2.1 [MPLS: Label 12000]  1.123 ms  1.045 ms  1.067 ms

   2  192.168.4.1 [MPLS: Label 14000]  1.123 ms  1.045 ms  1.067 ms

   2  192.168.5.1 [MPLS: Label 15000]  1.123 ms  1.045 ms  1.067 ms



   An example of MPLS traceroute failure due to NRP resource
   unavailability:

   > traceroute 15000 via label-stack 12000, 14000, NRP-ID: 1, Ret-NRP-
   ID: 2

   Tracing the route to 15000

   1  192.168.2.1 [MPLS: Label 12000]  Return Code: 'N'

   6. Security Considerations

   This document does not impose any additional security challenges to
   be considered beyond the security threats described in [RFC4884],
   [RFC4443], [RFC0792], [RFC8754], and [RFC8986].



Gong & Lin, et al.    Expires January 09, 2024                [Page 7]

Internet-Draft         OAM for NRP in MPLS Network           July 2025


   7. IANA Considerations

7.1. MPLS Reply Error Code

   IANA is requested to allocated new Return Codes "Return Subcode"
   registry.

      Value    Meaning

      -----    -------

        TBD    NRP resource unavailable



   8. References

8.1. Normative References

   [RFC9543] Farrel, A., Ed., Drake, J., Ed., Rokui, R., Homma, S.,
             Makhijani, K., Contreras, L., and J. Tantsura, "A
             Framework for Network Slices in Networks Built from IETF
             Technologies", RFC 9543, DOI 10.17487/RFC9543, March 2024,
             <https://www.rfc-editor.org/info/rfc9543>.

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



8.2. Informative References

   TBD

Acknowledgements

   TBD







Gong & Lin, et al.    Expires January 09, 2024                [Page 8]

Internet-Draft         OAM for NRP in MPLS Network           July 2025


Authors' Addresses

   Liyan Gong
   China Mobile
   China
   Email: gongliyan@chinamobile.com

   Changwang Lin
   New H3C Technologies
   China
   Email: linchangwang.04414@h3c.com





































Gong & Lin, et al.    Expires January 09, 2024                [Page 9]

