



detnet                                                          Q. Xiong
Internet-Draft                                                    A. Liu
Intended status: Standards Track                         ZTE Corporation
Expires: 2 January 2026                                        R. Gandhi
                                                     Cisco Systems, Inc.
                                                                 D. Yang
                                             Beijing Jiaotong University
                                                             1 July 2025


               Data Fields for DetNet Enhanced Data Plane
                 draft-xiong-detnet-data-fields-edp-03

Abstract

   The DetNet-specific metadata should be carried in enhanced data plane
   based on the enhancement requirements.  This document proposes the
   common DetNet data fields and option types such as Aggregation Option
   and Deterministic Latency Option.  The common DetNet Data-Fields can
   be encapsulated into a variety of protocols such as MPLS, IPv6 and
   SRv6 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
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   Drafts is at https://datatracker.ietf.org/drafts/current/.

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

   This Internet-Draft will expire on 2 January 2026.

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 (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



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   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  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Conventions used in this document . . . . . . . . . . . . . .   3
     2.1.  Requirements Language . . . . . . . . . . . . . . . . . .   3
     2.2.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   4
     2.3.  Abbreviations . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Specific Metadata for DetNet Enhanced Data Plane  . . . . . .   4
     3.1.  Aggregation-based Metadata  . . . . . . . . . . . . . . .   4
     3.2.  Deterministic Latency Metadata  . . . . . . . . . . . . .   5
   4.  Data Fields for DetNet Enhanced Data Plane  . . . . . . . . .   6
     4.1.  DetNet Option-Types and Data-Fields . . . . . . . . . . .   6
     4.2.  Aggregation Option  . . . . . . . . . . . . . . . . . . .   7
     4.3.  Deterministic Latency Option  . . . . . . . . . . . . . .   8
       4.3.1.  Data Field in Right-bounded Category  . . . . . . . .   9
       4.3.2.  Date Field in Flow Level Periodic Bounded Category  .  10
       4.3.3.  Date Field in Class Level Periodic Bounded
               Category  . . . . . . . . . . . . . . . . . . . . . .  10
       4.3.4.  Date Field in Flow Level Non-periodic Bounded
               Category  . . . . . . . . . . . . . . . . . . . . . .  11
       4.3.5.  Date Field in Class Level Non-periodic Bounded
               Category  . . . . . . . . . . . . . . . . . . . . . .  11
       4.3.6.  Date Field in Flow Level Rate-based Unbounded
               Category  . . . . . . . . . . . . . . . . . . . . . .  12
       4.3.7.  Date Field in Flow Level Rate-based Left-bounded
               Category  . . . . . . . . . . . . . . . . . . . . . .  12
   5.  Encapsulation Considerations for DetNet Enhanced Data
           Plane . . . . . . . . . . . . . . . . . . . . . . . . . .  13
     5.1.  Metadata for DetNet Enhanced Data Plane . . . . . . . . .  13
     5.2.  Encoding for DetNet Enhanced Data Plane . . . . . . . . .  14
       5.2.1.  Reuse of the Existing DSCP/TC Field . . . . . . . . .  14
       5.2.2.  New Common Data Fields  . . . . . . . . . . . . . . .  14
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  14
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  14
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  15
   9.  Informative References  . . . . . . . . . . . . . . . . . . .  15
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  18









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1.  Introduction

   According to [RFC8655], Deterministic Networking (DetNet) operates at
   the IP layer and delivers service which provides extremely low data
   loss rates and bounded latency within a network domain.  DetNet data
   planes has been specified in [RFC8938].  As described in [RFC9320],
   the end-to-end bounded latency depends on the value of queuing delay
   bound along with the queuing mechanisms.  Multiple queuing mechanisms
   has been proposed to guarantee the bounded latency in IEEE802.1 TSN
   (Time-Sensitive Networking) Task Group.  But the existing
   deterministic technologies are facing large-scale number of nodes and
   long-distance transmission, traffic scheduling, dynamic flows, and
   other controversial issues in large-scale networks.  The DetNet is
   required to support a enhanced data plane method of flow
   identification and packet treatment.

   For scaling networks, [I-D.ietf-detnet-scaling-requirements] has
   described the enhancement requirements for DetNet enhanced data
   plane, such as aggregated flow identification and deterministic
   latency guarantees.  For example, the flow identification with
   service-level aggregation and explicit aggregated flow identification
   should be supported.  And queuing mechanisms and solutions require
   different information to be defined as the DetNet-specific metadata
   to help the functions of ensuring deterministic latency, including
   regulation, queue management, etc.  Several data plane enhancement
   solutions and queuing mechanisms have been discussed in DetNet.  And
   [I-D.ietf-detnet-dataplane-taxonomy] has defined the classification
   criteria and the suitable categories for DetNet data plane solutions.

   This document proposes the specific metadata which should be carried
   in DetNet Enhanced Data Plane (EDP) and proposes the common DetNet
   data fields and option types such as Aggregation Option and
   Deterministic Latency Option.  The common DetNet Data-Fields can be
   encapsulated into a variety of protocols such as MPLS, IPv6 and SRv6
   networks.

2.  Conventions used in this document

2.1.  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.






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2.2.  Terminology

   This document uses the terms defined in [RFC8655], [RFC8938],
   [I-D.ietf-detnet-scaling-requirements] and
   [I-D.ietf-detnet-dataplane-taxonomy].

2.3.  Abbreviations

   SRH:Segment Routing Header

   SRv6:Segment Routing for IPv6 forwarding plane

   DL:Deterministic Latency

   CSQF:Cycle Specified Queuing and Forwarding

   TQF:Timeslot Queuing and Forwarding

   C-SCORE:Work Conserving Stateless Core Fair Queuing

   EDF:Earliest Deadline First

   TAS:Time Aware Shaper

   ATS:Asynchronous Traffic Shaping

   CQF:Cyclic Queuing and Forwarding

   FQ:Fair Queuing

   TSN:Time-Sensitive Networking

   ECQF:Enhanced Cyclic Queuing and Forwarding

   gLBF:guaranteed Latency Based Forwarding

   EDP:DetNet Enhanced Data Plane

3.  Specific Metadata for DetNet Enhanced Data Plane

3.1.  Aggregation-based Metadata

   As per [RFC8655], the DetNet data plane must support the aggregation
   of DetNet flows in order to support larger numbers of DetNet flows
   and improve scalability by reducing the per-hop states.  And the flow
   aggregation may be necessary for scaling networks.  As per
   [I-D.ietf-detnet-scaling-requirements], the deterministic services
   may demand different deterministic QoS requirements according to



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   different levels of application requirements.  The flow
   identification with service-level aggregation and explicit aggregated
   flow identification should be supported.  In DetNet MPLS, A-Label
   defined as per [RFC8964] can be added explicitly to the packets.  But
   in other DetNet data plane, no aggregated flow specific information
   is available.

   Furthermore, it is required to be dynamic and simplified to ensure
   the aggregated flows have compatible DetNet flow-specific QoS
   characteristics.  The individual flows may be aggregated for
   treatment based on shared service specification on aggregated-class
   level which identified by an aggregation class as per
   [I-D.xiong-detnet-flow-aggregation].  This document proposes the
   aggregation-based metadata in enhanced data plane for the DetNet
   nodes along the path to identify the aggregated flow and achieve the
   end-to-end QoS in scaling networks.

3.2.  Deterministic Latency Metadata

   As described in [RFC9320], the end-to-end bounded latency depends on
   the queuing delay bound and the queuing mechanisms.  Multiple queuing
   mechanisms have been proposed such as TAS [IIEEE802.1Qbv], CBS
   [IEEE802.1Q-2014], ATS [IEEE802.1Qcr], CQF [IEEE802.1Qch] and so on.
   In scaling networks which has large variation in latency among hops,
   great number of flows and multiple domains.
   [I-D.ietf-detnet-scaling-requirements] has described the technical
   requirements for enhanced data plane solutions.  Many variations and
   extensions of queuing mechanisms have been proposed to resolve the
   scalability issues in DetNet.  For example, the CQF variations for
   cyclic-based scheduling includes the ECQF [IEEE 802.1Qdv], TCQF
   [I-D.eckert-detnet-tcqf] and CSQF
   [I-D.chen-detnet-sr-based-bounded-latency].  The TAS variations for
   timeslot-based scheduling includes TQF
   [I-D.peng-detnet-packet-timeslot-mechanism].  The FQ variations for
   rate-based scheduling includes C-SCORE
   [I-D.joung-detnet-stateless-fair-queuing], ATS [IEEE802.1Qcr] and
   gLBF [I-D.eckert-detnet-glbf].  The EDF variations for deadline-based
   scheduling includes EDF [I-D.peng-detnet-deadline-based-forwarding].

   And when queuing mechanisms used in large-scale networks, the per-
   flow states can not be maintained with scalability issues.  Some
   queuing parameters should be carried for coordination between nodes
   so as to make appropriate packet forwarding and scheduling decisions
   to meet the time bounds.  As per
   [I-D.ietf-detnet-scaling-requirements], the information used by
   functions ensuring deterministic latency should be supported as such
   queuing-based information.  And queuing mechanisms and solutions
   require different information to help the functions of ensuring



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   deterministic latency, including regulation, queue management.  The
   deterministic latency metadata should be defined as the DetNet-
   specific metadata for DetNet enhanced data plane.

   [I-D.ietf-detnet-dataplane-taxonomy] has defined the classification
   criteria and the suitable categories for this solutions.  This
   proposes the deterministic latency metadata align with the categories
   in enhanced data plane for the DetNet nodes along the path to apply
   the queuing mechanisms and get the related deterministic latency
   metadata in the packet to achieve the end-to-end bounded latency.

4.  Data Fields for DetNet Enhanced Data Plane

4.1.  DetNet Option-Types and Data-Fields

   The enhanced functions and related metadata for DetNet should be
   confirmed before the encapsulations.  While more than one metadata
   should be carried in enhanced data plane, the common DetNet header
   should be considered to cover all option-types and data as Figure 1.

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | DetNet-Type   | DetNet-Length |         RESERVED              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      ~                 DetNet Option and Data Space                  ~
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                 Figure 1 DetNet Header for Enhanced Data Plane

   DetNet-Type: 8-bit unsigned integer, defining the DetNet Option-type
   for enhanced DetNet.  This document defines two options and option-
   types:

   Aggregation Option-Type, TBD1, as defined in section 4.2.

   Deterministic Latency Option-Type, TBD2, as defined in section 4.3.

   DetNet-Length: 8-bit unsigned integer, defined the Length of the
   DetNet Header 4-octet units.











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   DetNet Option and Data Space: variable, it MUST be aligned by 4
   octets.  It carries data that is added by the DetNet encapsulating
   node and interpreted by the decapsulating node.  The DetNet transit
   nodes MAY process the data by forwarding the option data determined
   by option type and may modify it.  The DetNet Option consists of a
   fixed-size "Option Header" and a variable-size "Option Data".  The
   Header and Data may be encapsulated continuously or separately.  A
   Data or more than one Data in lists can be carried in packets.

4.2.  Aggregation Option

   The format of Aggregation Option Header is shown in Figure 2.

        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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |      Aggregation  Type        |       Flag  |E|   Data Len    |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                 Figure 2 Aggregation Option Header

   Aggregation type(16 bits): indicates the aggregation type of packet
   treatment ensuring the deterministic latency as Figure 3 shown.  This
   type can also indicate the aggregated class.

           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
           | Value |         Aggregation Type            |
           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
           |0x0000 |  Reserved                           |
           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
           |0x0100 |  Bandwidth guarantee                |
           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
           |0x0200 |  Jitter guarantee                   |
           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
           |0x0300 |  Delay guarantee                    |
           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
           |0x0400 |  Low delay and jitter guarantee     |
           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
           |0x0500 |Ultra-low delay and jitter guarantee |
           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                      Figure 3  Aggregation Type

   Flag: 8-bit flags field.  When E is set to 1, it indicates the
   explicit aggregated flow identification.

   Data Len:8-bit unsigned integer.  Length of option data, in octets.




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   The related option data is defined as Aggregation Option Data in
   Figure 4.

        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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |              Aggregation ID                                   |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |              End-to-end Delay Budget                          |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |              End-to-end Delay Variation Budget                |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                  Figure 4 Aggregation Option Data

   Aggregation ID: 32bits.  It provides explicit and unique identifier
   for aggregated flow identification.  DetNet nodes performing
   aggregation using aggregation ID.

   End-to-end Delay Budget: 32bits.  It provides the value of end-to-end
   delay budget for the aggregated flow.

   End-to-end Delay Variation Budget: 32bits.  It provides the value of
   end-to-end delay variation budget for the aggregated flow.

4.3.  Deterministic Latency Option

   The format of Deterministic Latency Option Header is shown in
   Figure 5.

        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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       | Deterministic Latency Type    |   Flag        |   Data Len    |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                  Figure 5 Deterministic Latency Option header

   Deterministic Latency Type(16 bits): indicates the type of
   deterministic latency information with related queuing and scheduling
   metadata and it aglined with the suitable categories as defined in
   [I-D.ietf-detnet-dataplane-taxonomy] and shown in Figure 6.









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           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
           | Value  | Deterministic Latency Type                 |
           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
           |0x0000  | Unassigned                                 |
           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
           |0x0001  | Right-bounded category                     |
           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
           |0x0002  | Flow level periodic bounded category       |
           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
           |0x0003  | Class level periodic bounded category      |
           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
           |0x0004  | Flow level non-periodic bounded category   |
           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
           |0x0005  | Class level non-periodic bounded category  |
           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
           |0x0006  | Flow level rate based unbounded category   |
           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
           |0x0007  | Flow level rate based left-bounded category|
           +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                  Figure 6 Deterministic Latency Type

   Flag: 8-bit flags field.  Data Len: 8-bit unsigned integer.  Length
   of option data, in octets.

   The related option data is defined as Deterministic Latency option
   data which provides function-based or queuing-based information for a
   node to forward a DetNet flow.  The data of which is determined by
   the deterministic latency type.  The DetNet option data can be
   provided one time or in list.  The examples of different types of
   data is as following sections shown.

4.3.1.  Data Field in Right-bounded Category

   As per [I-D.ietf-detnet-dataplane-taxonomy], for solutions in the
   right-bounded category, a packet has only a maximum time bound.

   When the type is set to 0x0001, indicates the queuing and scheduling
   solutions in right-bounded category.  The data field and related
   information may be carried and designed as following shown:

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                    Maximum time bound                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

             Figure 7 Data Field in Right-bounded Category



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   Maximum time bound: 32bits, indicates the required maximum time bound
   of a packet.

4.3.2.  Date Field in Flow Level Periodic Bounded Category

   As per [I-D.ietf-detnet-dataplane-taxonomy], the flow Level periodic
   bounded solutions define a set of time slots, which will be scheduled
   for flows or flow aggregates.

   When the type is set to 0x0002, indicates the queuing and scheduling
   solutions in flow level periodic bounded category.  The data field
   and related information may be carried and designed as following
   shown:

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                            Timeslot ID                        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

         Figure 8 Data Field in Flow Level Periodic Bounded Category

   Timeslot ID: indicates the identifier of the timeslot scheduled for a
   flow.

4.3.3.  Date Field in Class Level Periodic Bounded Category

   As per [I-D.ietf-detnet-dataplane-taxonomy], the periodic bounded
   solutions can be further categorized by the traffic granularity with
   class level subcategory.  The class Level periodic bounded solutions
   define a set of cycles and each cycle will be scheduled for flows or
   flow aggregates within a class level.

   When the type is set to 0x0003, indicates the queuing and scheduling
   solutions in class level periodic bounded category.  The data field
   and related information may be carried and designed as following
   shown:

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                     Cycle ID                                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

        Figure 9 Data Field in Class Level Periodic Bounded Category

   Cycle ID (32bits): indicates the identifer which the queue applied
   for a node to forward DetNet flows within a class level.



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4.3.4.  Date Field in Flow Level Non-periodic Bounded Category

   As per [I-D.ietf-detnet-dataplane-taxonomy], flow level non-periodic
   bounded solutions guarantee the minimum and maximum bounds of a
   packet in a flow or flow aggregate.

   When the type is set to 0x0004, indicates the queuing and scheduling
   solutions in flow level non-periodic bounded category The data field
   and related information may be carried and designed as following
   shown:

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                    Maximum time bound                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                    Minimum time bound                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      Figure 10 Data Field in Flow Level Non-periodic Bounded Category

   Maximum time bound: 32bits, indicates the maximum time bound of a
   packet in a flow or flow aggregates.

   Minimum time bound: 32bits, indicates the minimum time bound of a
   packet in a flow or flow aggregates.

4.3.5.  Date Field in Class Level Non-periodic Bounded Category

   As per [I-D.ietf-detnet-dataplane-taxonomy], class level non-periodic
   bounded solutions guarantee the minimum and maximum bounds of a
   packet within a class level.

   When the type is set to 0x0005, indicates the queuing and scheduling
   solutions in class level non-periodic bounded category.  The data
   field and related information may be carried and designed as
   following shown:

     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
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                    Maximum time bound                         |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                    Minimum time bound                         |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

       Figure 11 Data Field in Class Level Non-periodic Bounded Category




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   Maximum time bound: 32bits, indicates the maximum time bound of a
   packet within a class level .

   Minimum time bound: 32bits, indicates the minimum time bound of a
   packet within a class level.

4.3.6.  Date Field in Flow Level Rate-based Unbounded Category

   In flow level rate based unbounded category, the latency bound is
   primarily influenced by the ratio of a flow's maximum packet size,
   its allocated service rate and completion time.

   When the type is set to 0x0006, indicates the queuing and scheduling
   solutions in flow level rate based unbounded category.  The data
   field and related information may be carried and designed as
   following shown:

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Maximum packet size                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                          Service rate                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                          Finish time                          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

       Figure 12 Data Field in Flow Level Rate-based Unbounded Category

   Maximum packet size: 32 bits, indicates the maximum packet size of a
   flow.

   Service rate: 32 bits, indicates the allocated service rate of a
   flow.

   Finish time: 32 bits, indicates the required service completion time
   of a flow.

4.3.7.  Date Field in Flow Level Rate-based Left-bounded Category

   In flow level rate based left-bounded category, the latency bound is
   primarily influenced by the ratio of a flow's maximum packet size,
   its allocated service rate, start time and completion time.

   When the type is set to 0x0007, indicates the queuing and scheduling
   solutions in flow level Rate based left-bounded category.  The data
   field and related information may be carried and designed as
   following shown:



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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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Maximum packet size                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                          Service rate                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                          Finish time                          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                         Eligible time                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

     Figure 13 Data Field in Flow Level Rate-based Left-bounded Category

   Maximum packet size: 32 bits, indicates the maximum packet size of a
   flow.

   Service rate: 32 bits, indicates the allocated service rate of a
   flow.

   Finish time: 32 bits, indicates the required service completion time
   of a flow.

   Eligible time: 32bits, indicates the required service start time of a
   flow.

5.  Encapsulation Considerations for DetNet Enhanced Data Plane

5.1.  Metadata for DetNet Enhanced Data Plane

   The packet treatment should indicate the behaviour action ensuring
   the deterministic latency at DetNet nodes such as queuing-based
   mechanisms.  The deterministic latency type and related parameters
   such as queuing-based information should be carried as metadta in
   data plane.  And the definitions may follow these polices.

   The data plane enhancement must be generic and the format must be
   applied to all functions and queuing mechanisms.  The metadata and
   definitions should be common among different candidate queuing
   solutions.

   Information and metadata MUST be simplified and limited to be carried
   in DetNet packets for provided deterministic latency related
   scheduling along the forwarding path.  For example, the queuing-based
   information should be carried in metadata for coordination between
   nodes.





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   The requirement of the flow or service may be not suitable to be
   carried explicitly in DetNet data plane.  The packet treatment should
   schedule the resources and indicate the behaviour to ensure the
   deterministic latency in forwarding sub-layer.  So the queuing
   mechanisms could be viewed as a type of deterministic resources.  The
   resources type and queuing type should be explicitly indicated.

5.2.  Encoding for DetNet Enhanced Data Plane

5.2.1.  Reuse of the Existing DSCP/TC Field

   Reusing the DSCP or existing field is reasonable and simple to define
   and easy to standardize.  For example, in IPv4 and traditional MPLS
   networks, it is not suitable to carry new metadata and it is
   suggested to reuse the original bits such as DSCP as per
   [I-D.eckert-detnet-tcqf].  The mapping from DSCP and the metadata
   such as queuing information MUST be provided in the controller plane.

5.2.2.  New Common Data Fields

   DSCP value may be not sufficient and hard to distinguish between the
   original DiffServ service and the deterministic service.  The DetNet-
   specific metadata can also be encoded as a common data fields and the
   definition of data fields is independent from the encapsulating
   protocols.  The data fields could be encapsulated into a variety of
   protocols, such as MPLS MNA [I-D.sxg-mpls-mna-deterministic-latency],
   IPv6 [I-D.xiong-detnet-6man-queuing-option] and SRv6
   [I-D.xiong-detnet-spring-srh-extensions].

6.  Security Considerations

   Security considerations for DetNet are covered in the DetNet
   Architecture [RFC8655] and DetNet data plane [RFC8938], [RFC8939],
   [RFC8964] and DetNet security considerations [RFC9055].  The security
   considerations specified in [I-D.ietf-detnet-scaling-requirements]
   are also applicable to the procedures defined in this document.

7.  IANA Considerations

   IANA has defined a registry group named "DetNet Data Fields".  This
   group includes the DetNet Option-Type registry.  This registry
   defines code points for the DetNet Option-Type field for identifying
   DetNet-Option-Types.  The following code points are defined in this
   document:

   TBD1: DetNet Aggregation Option-Type

   TBD2: DetNet Deterministic Latency Option-Type



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8.  Acknowledgements

   The authors would like to acknowledge Peng Liu, Bin Tan for his
   thorough review and very helpful comments.

9.  Informative References

   [I-D.chen-detnet-sr-based-bounded-latency]
              Chen, M., Geng, X., Li, Z., Joung, J., and J. Ryoo,
              "Segment Routing (SR) Based Bounded Latency", Work in
              Progress, Internet-Draft, draft-chen-detnet-sr-based-
              bounded-latency-03, 7 July 2023,
              <https://datatracker.ietf.org/doc/html/draft-chen-detnet-
              sr-based-bounded-latency-03>.

   [I-D.eckert-detnet-glbf]
              Eckert, T. T., Clemm, A., Bryant, S., and S. Hommes,
              "Deterministic Networking (DetNet) Data Plane - guaranteed
              Latency Based Forwarding (gLBF) for bounded latency with
              low jitter and asynchronous forwarding in Deterministic
              Networks", Work in Progress, Internet-Draft, draft-eckert-
              detnet-glbf-04, 3 March 2025,
              <https://datatracker.ietf.org/doc/html/draft-eckert-
              detnet-glbf-04>.

   [I-D.eckert-detnet-tcqf]
              Eckert, T. T., Li, Y., Bryant, S., Malis, A. G., Ryoo, J.,
              Liu, P., Li, G., Ren, S., and F. Yang, "Deterministic
              Networking (DetNet) Data Plane - Tagged Cyclic Queuing and
              Forwarding (TCQF) for bounded latency with low jitter in
              large scale DetNets", Work in Progress, Internet-Draft,
              draft-eckert-detnet-tcqf-07, 3 March 2025,
              <https://datatracker.ietf.org/doc/html/draft-eckert-
              detnet-tcqf-07>.

   [I-D.ietf-detnet-dataplane-taxonomy]
              Joung, J., Geng, X., Peng, S., and T. T. Eckert,
              "Dataplane Enhancement Taxonomy", Work in Progress,
              Internet-Draft, draft-ietf-detnet-dataplane-taxonomy-03, 2
              March 2025, <https://datatracker.ietf.org/doc/html/draft-
              ietf-detnet-dataplane-taxonomy-03>.










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   [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-08, 1 June 2025,
              <https://datatracker.ietf.org/doc/html/draft-ietf-detnet-
              scaling-requirements-08>.

   [I-D.joung-detnet-stateless-fair-queuing]
              Joung, J., Ryoo, J., Cheung, T., Li, Y., and P. Liu,
              "Latency Guarantee with Stateless Fair Queuing", Work in
              Progress, Internet-Draft, draft-joung-detnet-stateless-
              fair-queuing-05, 20 June 2025,
              <https://datatracker.ietf.org/doc/html/draft-joung-detnet-
              stateless-fair-queuing-05>.

   [I-D.peng-detnet-deadline-based-forwarding]
              Peng, S., Du, Z., Basu, K., cheng, C., Yang, D., and C.
              Liu, "Deadline Based Deterministic Forwarding", Work in
              Progress, Internet-Draft, draft-peng-detnet-deadline-
              based-forwarding-17, 25 June 2025,
              <https://datatracker.ietf.org/doc/html/draft-peng-detnet-
              deadline-based-forwarding-17>.

   [I-D.peng-detnet-packet-timeslot-mechanism]
              Peng, S., Liu, P., Basu, K., Liu, A., Yang, D., and G.
              Peng, "Timeslot Queueing and Forwarding Mechanism", Work
              in Progress, Internet-Draft, draft-peng-detnet-packet-
              timeslot-mechanism-12, 24 June 2025,
              <https://datatracker.ietf.org/doc/html/draft-peng-detnet-
              packet-timeslot-mechanism-12>.

   [I-D.sxg-mpls-mna-deterministic-latency]
              Song, X., Xiong, Q., and R. Gandhi, "MPLS Network Action
              for Deterministic Latency", Work in Progress, Internet-
              Draft, draft-sxg-mpls-mna-deterministic-latency-03, 15
              June 2025, <https://datatracker.ietf.org/doc/html/draft-
              sxg-mpls-mna-deterministic-latency-03>.

   [I-D.xiong-detnet-6man-queuing-option]
              Xiong, Q., Zhao, J., and R. Gandhi, "IPv6 Option for
              Scaling Deterministic Networks", Work in Progress,
              Internet-Draft, draft-xiong-detnet-6man-queuing-option-06,
              1 July 2024, <https://datatracker.ietf.org/doc/html/draft-
              xiong-detnet-6man-queuing-option-06>.






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   [I-D.xiong-detnet-flow-aggregation]
              Xiong, Q., Jiang, T., and J. Joung, "Flow Aggregation for
              Enhanced DetNet", Work in Progress, Internet-Draft, draft-
              xiong-detnet-flow-aggregation-02, 25 February 2025,
              <https://datatracker.ietf.org/doc/html/draft-xiong-detnet-
              flow-aggregation-02>.

   [I-D.xiong-detnet-spring-srh-extensions]
              Xiong, Q., Wu, H., and D. Yang, "Segment Routing Header
              Extensions for DetNet Data Fields", Work in Progress,
              Internet-Draft, draft-xiong-detnet-spring-srh-extensions-
              02, 1 July 2024, <https://datatracker.ietf.org/doc/html/
              draft-xiong-detnet-spring-srh-extensions-02>.

   [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/rfc/rfc2119>.

   [RFC2212]  Shenker, S., Partridge, C., and R. Guerin, "Specification
              of Guaranteed Quality of Service", RFC 2212,
              DOI 10.17487/RFC2212, September 1997,
              <https://www.rfc-editor.org/rfc/rfc2212>.

   [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/rfc/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/rfc/rfc8655>.

   [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/rfc/rfc8938>.

   [RFC8939]  Varga, B., Ed., Farkas, J., Berger, L., Fedyk, D., and S.
              Bryant, "Deterministic Networking (DetNet) Data Plane:
              IP", RFC 8939, DOI 10.17487/RFC8939, November 2020,
              <https://www.rfc-editor.org/rfc/rfc8939>.

   [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/rfc/rfc8964>.




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   [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/rfc/rfc9055>.

   [RFC9320]  Finn, N., Le Boudec, J.-Y., Mohammadpour, E., Zhang, J.,
              and B. Varga, "Deterministic Networking (DetNet) Bounded
              Latency", RFC 9320, DOI 10.17487/RFC9320, November 2022,
              <https://www.rfc-editor.org/rfc/rfc9320>.

Authors' Addresses

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


   Aihua Liu
   ZTE Corporation
   Email: liu.aihua@zte.com.cn


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


   Dong Yang
   Beijing Jiaotong University
   Email: dyang@bjtu.edu.cn





















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