



MPLS                                                             X. Song
Internet-Draft                                                 ZTE Corp.
Intended status: Standards Track                               G. Mirsky
Expires: 11 July 2026                                           B. Varga
                                                                Ericsson
                                                               R. Gandhi
                                                     Cisco Systems, Inc.
                                                                Q. Xiong
                                                               ZTE Corp.
                                                          7 January 2026


            MPLS Network Action for Deterministic Networking
                     draft-ietf-mpls-mna-detnet-00

Abstract

   This document specifies formats and mechanisms for using MPLS Network
   Actions (MNA) to support Deterministic Networking (DetNet) services,
   including bounded latency, low loss and in-order delivery.  It
   defines MPLS In-Stack and Post-Stack MNA for carrying DetNet-specific
   information, such as flow identification, sequence number, and
   latency information, which are forwarded over an MPLS technology-
   based network domain.

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

   Internet-Drafts are draft documents valid for a maximum of six months
   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 11 July 2026.

Copyright Notice

   Copyright (c) 2026 IETF Trust and the persons identified as the
   document authors.  All rights reserved.





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   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.  Code Components
   extracted from this document must include Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
     2.1.  Terms Used in This Document . . . . . . . . . . . . . . .   3
     2.2.  Abbreviations . . . . . . . . . . . . . . . . . . . . . .   3
     2.3.  Requirements Language . . . . . . . . . . . . . . . . . .   4
   3.  DetNet-specific MNA . . . . . . . . . . . . . . . . . . . . .   4
   4.  MPLS In-Stack Encoding for DetNet . . . . . . . . . . . . . .   5
     4.1.  DetNet-specific NASes . . . . . . . . . . . . . . . . . .   5
     4.2.  Characteristics of DetNet NASes . . . . . . . . . . . . .   6
     4.3.  Examples of DetNet NASes in MPLS In-Stack . . . . . . . .   7
     4.4.  Aggregation Example . . . . . . . . . . . . . . . . . . .   8
   5.  MPLS Post-Stack Encoding for DetNet . . . . . . . . . . . . .   9
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  12
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  12
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  12
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  13
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  14

1.  Introduction

   The DetNet work group has defined the Packet Replication Function
   (PRF) and Packet Elimination Function (PEF) to achieve extremely low
   packet loss.  In general, usage of these per-packet replication and
   elimination functions may result in out-of-order delivery of frames/
   packets [RFC8655].  This characteristic of PRF/PEF has been
   identified by the IETF, and a Packet Ordering Function (POF) was
   defined [RFC9550].  The POF function is a DetNet service sub-layer
   function similar to PRF and PEF.  All the DetNet service sub-layer
   functions are usually referred to as Packet Replication, Elimination,
   and Ordering Functions (PREOF).








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   These DetNet service sub-layer-related functions require ordering
   information (e.g., sequence number).  IETF DetNet WG has defined how
   sequencing information (i.e., sequence number) travels with DetNet
   packets using the d-CW [RFC8964] when PW (PseudoWire) technology is
   used with an MPLS Data Plane.

   The DetNet forwarding sub-layer-related functions focus on ensuring
   the bounded latency requirements and may use packet-specific latency
   information during forwarding.  No solution was defined for adding
   such latency-specific information to the PW encapsulated DetNet
   packets.

   This document presents MPLS MNA solutions for DetNet functions
   support.  It follows the MPLS MNA requirements specified at [RFC9613]
   and MPLS MNA In-Stack header specifid at [I-D.ietf-mpls-mna-hdr] and
   MNA Post-Stack header specified at [I-D.ietf-mpls-mna-ps-hdr] to
   support basic DetNet service and DetNet service with enhanced DetNet
   data plane requirements specified at
   [I-D.ietf-detnet-scaling-requirements] .

2.  Terminology

2.1.  Terms Used in This Document

   This document uses the terminology established in the DetNet
   architecture [RFC8655].  The reader is assumed to be familiar with
   that document and its terminology.

2.2.  Abbreviations

   The following abbreviations are used in this document:

   DetNet        Deterministic Networking

   Flow-ID       Flow Identifier

   MNA           MPLS Network Action

   NAI           Network Action Indicator

   NAS           Network Action Sub-Stack

   LSE           Label Stack Entry

   PEF           Packet Elimination Function

   POF           Packet Ordering Function




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   PREOF         Packet Replication, Elimination and Ordering Functions

   PRF           Packet Replication Function

   PSD           Post-Stack Data

   SeqNum        Sequence Number

2.3.  Requirements Language

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

3.  DetNet-specific MNA

   Three information elements may be required during the forwarding of
   DetNet packets:

   1.  Flow identifier (Flow-ID)

   2.  Sequence information (SeqNum)

   3.  Latency information (LatencyInfo)

   "1" and "2" are used by the DetNet service sub-layer (i.e., by
   PREOF).  "1" and "3" are used by the DetNet forwarding sub-layer to
   ensure the bounded latency for a DetNet packet.

   The use of a DetNet-specific MNA solution allows using a single
   encapsulation format for all DetNet-specific parameters (Flow-ID,
   SeqNum, LatencyInfo) as MNA data, meaning that the Network Action
   Sub-stack (NAS) is carried as part of the MPLS label stack (i.e., In-
   Stack MNA solution).  DetNet-specific MNA enables more fine-tuned,
   scalable handling of latency-bound requirements, with service
   protection natively in MPLS.

   This document introduces two options for DetNet-specific MNA: In-
   Stack MPLS Network Action [see [I-D.ietf-mpls-mna-hdr]] and Post-
   Stack MPLS Network Action [see [I-D.ietf-mpls-mna-ps-hdr]].









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4.  MPLS In-Stack Encoding for DetNet

4.1.  DetNet-specific NASes

   The MPLS MNA encapsulation is used between DetNet Relay nodes.

   DetNet-specific parameters used during forwarding are: (1) Flow-ID,
   (2) SeqNum and (3) LatencyInfo.  For each of them, a specific NAS can
   be defined to carry the related variable in an MPLS MNA network:

   1.  PREOF-specific NAS (e.g., SeqNum)

   2.  Latency-specific NAS (e.g., LatencyClass)

   3.  Flow-specific NAS (i.e., Flow-ID)

   Note: DetNet aggregate flows can be described with the same set of
   parameters.

   DetNet functions use these NASes as follows:

   *  DetNet PREOF requires Flow-ID+SeqNum parameters.  They are used
      only at DetNet Relay nodes implementing the service sub-layer.

   *  DetNet latency-bound related functions use Flow-ID+LatencyInfo, to
      select proper queuing hop-by-hop along the transmission path.
      They are used at DetNet Transit nodes to implement the forwarding
      sub-layer.

   Using these NASes in DetNet scenarios results in the following MPLS
   encapsulation format example that ensures placing all DetNet
   parameters in the NASes:

   *  LSP(s) = F-Label(s): used for describing the forwarding path.

   *  MNA Sub-Stack Indicator.

   *  NAS-3: (NAI: Flow-ID, Ancillary Data (AD): i.e., Flow-ID).

   *  NAS-2: (NAI: Latency, Ancillary Data (AD): e.g., LatencyClass).

   *  NAS-1: (NAI: SeqNum, Ancillary Data (AD): i.e., SeqNum (16/28
      bits)).

   *  Payload.






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   Note that using PW (S-Label) in the label stack is optional, it is
   not prevented by the method described in this document and is not
   shown in the above example.

4.2.  Characteristics of DetNet NASes

   Characteristics of the DetNet-specific NASes are as follows:

   *  Encoding a Network Action: Different Operation Codes are used for
      the above DetNet-specific NASes.

   *  Scope is encoded implicitly, all DetNet NAIs (Network Action
      Indicator) have a predefined scope.

      -  All DetNet-specific NAIs use "Select" mode, so the use of these
         NAIs may be restricted for DetNet-aware nodes if the operator
         intends to do so.

      -  Optional scope for the NAIs:

         o  NAI: Flow-ID can have a Hop-by-hop (HBH) scope.

         o  NAI: Latency can have a Hop-by-hop (HBH) scope.

         o  NAI: SeqNum can have an Ingress-to-Egress (I2E) scope.

   *  Recognition action:

      -  NAI: Flow-ID is used for flow identification, and this NAI MUST
         be ignored if unrecognized.

      -  NAI: Latency is used by every node along the path that performs
         a latency-related action (e.g., queuing).  This NAI MUST be
         ignored if unrecognized.

      -  NAI: SegNum is used only by the last node on the path defined
         by the F-Label(s) that performs the PREOF action.  This NAI
         MUST be ignored if unrecognized.

   *  Encoding of Post-Stack Data: N/A for these NASes.

   By using the "Select" mode for the DetNet-specific NASes, the network
   operation can emulate the MS-PW (Multi-Segment PW) pop-push
   characteristics on the S-Label.  There is no need to define the whole
   forwarding graph across the MPLS network at the ingress.
   Furthermore, the "Select" mode allows the payload is an MPLS packet
   using the same label stack (as used by the MNA).




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4.3.  Examples of DetNet NASes in MPLS In-Stack

   The figures show some possible DetNet-specific NAS formats and their
   usage.

   DetNet Latency NAS: Format-B provides enough bits to encode, e.g.,
   several LatencyClass-es.  For longer latency-related parameters
   (e.g., timestamps) Format C/C+D can be used.


       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |              Label (MNA bSPL)         | TC  |S|      TTL      |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | Opcode=TBA1 |   Data (Latency Info)   |R|IHS|S| Res |U|  NASL |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


       Figure 1: The short DetNet Latency Information (e.g., several
                LatencyClass-es) Encoding Using LSE Format B

   DetNet SeqNum NAS: Depending on the location of the SeqNum parameter
   within the MNA part of the MPLS stack, a Format B+C/C/C+D is
   necessary (which contains 28/16 bits of the SeqNum).  In these
   formats, there are unused "Data bits" to carry additional FLAGs
   related to the SeqNum

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |              Label (MNA bSPL)         | TC  |S|      TTL      |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | Opcode=TBA2 |   Data (SeqNum)         |R|IHS|S| Res |U| NASL=1|
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | Opcode=TBA2 |   Data (cont.)                |S| Data  | NAL=0 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

     Figure 2: An Example of the DetNet Sequence Number Encoding Using
                            LSE Formats B and C

   DetNet Flow-ID NAS: Depending on the location of the Flow-ID, a
   Format C/B+C is necessary (which contains 20 bits of the ID).








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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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |              Label (MNA bSPL)         | TC  |S|      TTL      |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | Opcode=TBA3 |   Data (Flow-ID)        |R|IHS|S| Res |U| NASL=1|
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | Opcode=TBA3 |   Data (cont.)                |S|  Data | NAL=0 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

     Figure 3: An Example of the DetNet Flow Identifier Encoding Using
                            LSE Formats B and C

   Figure 4 below shows an MNA that contains all the DetNet-specific
   NASes.  MNA-6 contains the DetNet Latency parameter being encoded in
   Format-B.  MNA-7 contains the DetNet Flow-ID, and a 20-bit Flow-ID is
   encoded in Format C.  MNA-8 contains the DetNet SeqNum in Format C
   with a 16-bit sequence number.

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |              Label (MNA bSPL)         | TC  |S|      TTL      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Opcode=TBA1 |   Data (Latency Info)   |R|IHS|S| Res |U| NASL=2|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Opcode=TBA3 |   Data (Flow-ID)              |S| (FID) | NAL=0 |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Opcode=TBA2 |   Data (SeqNum)               |S|  0    | NAL=0 |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      Figure 4: An Example of the Combined DetNet Parameters Encoding
                                 Using MNA

4.4.  Aggregation Example

   Figure 5 shows an aggregation example where multiple DetNet flows are
   aggregated in a single aggregate.  NAS-A part contains the aggregate
   specific DetNet NASes, and NAS-F contains the flow-specific NASes of
   the data packet.











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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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |              Label (MNA bSPL)         | TC  |S|      TTL      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Opcode=TBA1 | Data (Aggr-Latency-Info)|R|IHS|S| Res |U| NASL=2|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Opcode=TBA3 | Data (Aggr-Flow-ID)           |S| (FID) | NAL=0 |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Opcode=TBA2 | Data (Aggr-SeqNum)            |S|   0   | NAL=0 |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |              Label (MNA bSPL)         | TC  |S|      TTL      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Opcode=TBA1 |   Data (Latency Info)   |R|IHS|S| Res |U| NASL=2|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Opcode=TBA3 |   Data (Flow-ID)              |S| (FID) | NAL=0 |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Opcode=TBA2 |   Data (SeqNum)               |S|  0    | NAL=0 |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

        Figure 5: An Example of the DetNet Aggregate Flow Parameters
                             Encoding Using MNA

   Note1: Opcodes are to be allocated by IANA during the
   standardization.

   Note2: Aggregation re-uses the same Options code points for the
   aggregated and specific flows.  The interpretation is based on the
   order of NASes.  During the de-aggregation of flows, the MNA
   containing the aggregate parameters is removed from the label stack
   (popped).

5.  MPLS Post-Stack Encoding for DetNet

   When the latency guarantee of a DetNet network is of the end-to-end
   (E2E) forwarding type, for the hop-by-hop (hbh) forwarding type that
   carries longer latency information, the carrying of latency
   information changes with the number of hops.  In such cases, it is
   recommended to use PSD encapsulation.  The opcode of DetNet used in
   MPLS In-Stack is reused for indication of PSD presence.











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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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |              Label (MNA bSPL)         | TC  |S|      TTL      |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | Opcode=TBA1 |           Data          |1|IHS|S| Res |U| NASL=0|
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Figure 6: PSD presence for DetNet Latency Encoding Using LSE Format B

   Opcode: In-Stack Opcode for DetNet action, requires allocation by
   IANA.  The PSD flag bit with P=1 is represented by the PSD encoding.
   The scope field specifies the operation processing method of IHS.

   Figure 7 shows an example of a PSD in which DetNet flow information
   is encoded in the MPLS Post-Stack NAS.  The latency information may
   be variable in case of Hop-by-Hop processing in DetNet networks.  In
   this example, it's assumed to have two NSIs to carry latency
   information (i.e., timestamps).  The Flow-ID field length is 20 bits,
   and the length of SeqNum is 28 bits carried in two NAIs.

    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |              Label (MNA bSPL)         | TC  |S|      TTL      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Opcode=TBA1 |           Data          |1|IHS|S| Res |U| NASL=0|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                 Label                       |1|               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |firstNi|Version| PS-HDR-LEN    | TYPE = MNA-POST-STACK-HDR = 1 |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Opcode=TBA1 |R|R|  PS-NAL=4   |    Data (Latency Info)  |NAL=1|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       Data (Cont.)                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Opcode=TBA3 |R|R|   Data (Flow-ID)                      |NAL=0|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Opcode=TBA2 |R|R|   Data (SeqNum)                       |NAL=1|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       Data (Cont.)                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

       Figure 7: An Example of the DetNet Flow Parameters Encoding in
                              MPLS Post-Stack






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   The first NAS in the Post-Stack is used to encapsulate the PSD
   header, indicating the total length, version, and type of the PSD
   header, and complies with [I-D.ietf-mpls-mna-ps-hdr].

   Opcode: The R bit is reserved, and PS-NAL is used to indicate the
   size of the NAS corresponding to DetNet network operations.

   The Flow-ID Opcode identifies a DetNet flow at the receiving DetNet
   service sub-layer processing node.  The SeqNum Opcode identifies the
   sequence number per DetNet-App flow, i.e., DetNet service.  The
   Sequence Number field lengths MUST be supported 0 bits, 16 bits and
   28 bits.  The Latency Opcode identifies the service type of DetNet
   flows or the latency information carried in MPLS networks.  The
   detailed information for latency format is for further study.

6.  Security Considerations

   Security considerations for DetNet are covered in the DetNet
   Architecture [RFC8655], DetNet Data Plane Framework [RFC8938] and
   DetNet Security Considerations [RFC9055].  MPLS security
   considerations are covered in [RFC8964], [RFC3031], [RFC3032].  These
   security considerations also apply to this document.  The MNA
   security considerations speicified at [I-D.ietf-mpls-mna-hdr],
   [I-D.ietf-mpls-mna-ps-hdr] and [RFC9789] are also applicable to the
   procedures defined in this document.

7.  IANA Considerations

   This document requests new IANA-managed code-points for DetNet
   encoded in MPLS In-Stack adn Post-Stack.  IANA maintains the "Network
   Action Opcodes" registry when created from IANA request in
   [I-D.ietf-mpls-mna-hdr].  IANA is requested to allocate new values
   for MPLS Network Action Opcode for DetNet Action from this registry:


















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     +========+=============+=======================+===============+
     | Opcode | Description | In-Stack and Post-    | Reference     |
     | Value  |             | Stack, In-Stack only, |               |
     |        |             | Post-Stack only       |               |
     +========+=============+=======================+===============+
     | TBA1   | Latency     | In-Stack and Post-    | This document |
     |        | Information | Stack                 |               |
     +--------+-------------+-----------------------+---------------+
     | TBA2   | Sequence    | In-Stack and Post-    | This document |
     |        | Number      | Stack                 |               |
     +--------+-------------+-----------------------+---------------+
     | TBA3   | Flow        | In-Stack and Post-    | This document |
     |        | Identifier  | Stack                 |               |
     +--------+-------------+-----------------------+---------------+

                        Table 1: DetNet MNA Opcode

8.  Acknowledgements

   Authors extend their appreciation to Adrian Farrel, Lou Berger, Joel
   Halpern, Janos Farkas, Ferenc Fejes, Tony Li, Tarek Saad, Jie Dong,
   Shaofu Peng and Loa Andersson for their insightful comments and
   contributions.

9.  References

9.1.  Normative References

   [I-D.ietf-mpls-mna-hdr]
              Rajamanickam, J., Gandhi, R., Zigler, R., Song, H., and K.
              Kompella, "MPLS Network Action (MNA) Sub-Stack Solution",
              Work in Progress, Internet-Draft, draft-ietf-mpls-mna-hdr-
              17, 1 December 2025,
              <https://datatracker.ietf.org/doc/html/draft-ietf-mpls-
              mna-hdr-17>.

   [I-D.ietf-mpls-mna-ps-hdr]
              Rajamanickam, J., Gandhi, R., Zigler, R., Li, T., and J.
              Dong, "Post-Stack MPLS Network Action (MNA) Solution",
              Work in Progress, Internet-Draft, draft-ietf-mpls-mna-ps-
              hdr-04, 20 November 2025,
              <https://datatracker.ietf.org/doc/html/draft-ietf-mpls-
              mna-ps-hdr-04>.

   [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>.



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   [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>.

   [RFC8655]  Finn, N., Thubert, P., Varga, B., and J. Farkas,
              "Deterministic Networking Architecture", RFC 8655,
              DOI 10.17487/RFC8655, October 2019,
              <https://www.rfc-editor.org/info/rfc8655>.

   [RFC8964]  Varga, B., Ed., Farkas, J., Berger, L., Malis, A., Bryant,
              S., and J. Korhonen, "Deterministic Networking (DetNet)
              Data Plane: MPLS", RFC 8964, DOI 10.17487/RFC8964, January
              2021, <https://www.rfc-editor.org/info/rfc8964>.

9.2.  Informative References

   [I-D.ietf-detnet-scaling-requirements]
              Liu, P., Li, Y., Eckert, T. T., Xiong, Q., Ryoo, J.,
              zhushiyin, and X. Geng, "Requirements for Scaling
              Deterministic Networks", Work in Progress, Internet-Draft,
              draft-ietf-detnet-scaling-requirements-09, 7 September
              2025, <https://datatracker.ietf.org/doc/html/draft-ietf-
              detnet-scaling-requirements-09>.

   [RFC3031]  Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol
              Label Switching Architecture", RFC 3031,
              DOI 10.17487/RFC3031, January 2001,
              <https://www.rfc-editor.org/info/rfc3031>.

   [RFC3032]  Rosen, E., Tappan, D., Fedorkow, G., Rekhter, Y.,
              Farinacci, D., Li, T., and A. Conta, "MPLS Label Stack
              Encoding", RFC 3032, DOI 10.17487/RFC3032, January 2001,
              <https://www.rfc-editor.org/info/rfc3032>.

   [RFC8938]  Varga, B., Ed., Farkas, J., Berger, L., Malis, A., and S.
              Bryant, "Deterministic Networking (DetNet) Data Plane
              Framework", RFC 8938, DOI 10.17487/RFC8938, November 2020,
              <https://www.rfc-editor.org/info/rfc8938>.

   [RFC9055]  Grossman, E., Ed., Mizrahi, T., and A. Hacker,
              "Deterministic Networking (DetNet) Security
              Considerations", RFC 9055, DOI 10.17487/RFC9055, June
              2021, <https://www.rfc-editor.org/info/rfc9055>.

   [RFC9550]  Varga, B., Ed., Farkas, J., Kehrer, S., and T. Heer,
              "Deterministic Networking (DetNet): Packet Ordering
              Function", RFC 9550, DOI 10.17487/RFC9550, March 2024,
              <https://www.rfc-editor.org/info/rfc9550>.



Song, et al.              Expires 11 July 2026                 [Page 13]

Internet-Draft                 DetNet MNA                   January 2026


   [RFC9613]  Bocci, M., Ed., Bryant, S., and J. Drake, "Requirements
              for Solutions that Support MPLS Network Actions (MNAs)",
              RFC 9613, DOI 10.17487/RFC9613, August 2024,
              <https://www.rfc-editor.org/info/rfc9613>.

   [RFC9789]  Andersson, L., Bryant, S., Bocci, M., and T. Li, "MPLS
              Network Actions (MNAs) Framework", RFC 9789,
              DOI 10.17487/RFC9789, July 2025,
              <https://www.rfc-editor.org/info/rfc9789>.

Authors' Addresses

   Xueyan Song
   ZTE Corp.
   Email: song.xueyan2@zte.com.cn


   Greg Mirsky
   Ericsson
   Email: gregimirsky@gmail.com


   Balazs Varga
   Ericsson
   Email: balazs.a.varga@ericsson.com


   Rakesh Gandhi
   Cisco Systems, Inc.
   Email: rgandhi@cisco.com


   Quan Xiong
   ZTE Corp.
   Email: xiong.quan@zte.com.cn
















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