Data Fields for DetNet Enhanced Data Plane
draft-xiong-detnet-data-fields-edp-04
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| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Authors | Quan Xiong , Aihua Liu , Jinoo Joung , Rakesh Gandhi , Dong Yang | ||
| Last updated | 2026-02-23 | ||
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draft-xiong-detnet-data-fields-edp-04
detnet Q. Xiong
Internet-Draft A. Liu
Intended status: Standards Track ZTE Corporation
Expires: 28 August 2026 J. Joung
Sangmyung University
R. Gandhi
Cisco Systems, Inc.
D. Yang
Beijing Jiaotong University
24 February 2026
Data Fields for DetNet Enhanced Data Plane
draft-xiong-detnet-data-fields-edp-04
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 options including Deterministic Latency
Option and Aggregation Option. It also considers the common DetNet
options being 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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This Internet-Draft will expire on 28 August 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
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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. Deterministic Latency Metadata . . . . . . . . . . . . . 5
3.2. Aggregation-based Metadata . . . . . . . . . . . . . . . 5
4. Data Fields for DetNet Enhanced Data Plane . . . . . . . . . 6
4.1. DetNet Options . . . . . . . . . . . . . . . . . . . . . 6
4.2. Deterministic Latency Option . . . . . . . . . . . . . . 7
4.2.1. Data Fields in Right-bounded Category . . . . . . . . 8
4.2.2. Date Fields in Flow Level Periodic Bounded
Category . . . . . . . . . . . . . . . . . . . . . . 9
4.2.3. Date Fields in Class Level Periodic Bounded
Category . . . . . . . . . . . . . . . . . . . . . . 9
4.2.4. Date Fields in Flow Level Non-periodic Bounded
Category . . . . . . . . . . . . . . . . . . . . . . 10
4.2.5. Date Fields in Class Level Non-periodic Bounded
Category . . . . . . . . . . . . . . . . . . . . . . 10
4.2.6. Date Fields in Flow Level Rate-based Unbounded
Category . . . . . . . . . . . . . . . . . . . . . . 11
4.2.7. Date Fields in Flow Level Rate-based Left-bounded
Category . . . . . . . . . . . . . . . . . . . . . . 12
4.3. Aggregation Option . . . . . . . . . . . . . . . . . . . 12
5. Encapsulation Considerations for DetNet Enhanced Data
Plane . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.1. Metadata for DetNet Enhanced Data Plane . . . . . . . . . 14
5.2. Encoding for DetNet Enhanced Data Plane . . . . . . . . . 14
5.2.1. Reuse of the Existing DSCP/TC Field . . . . . . . . . 14
5.2.2. Encapsulation in MPLS MNA . . . . . . . . . . . . . . 15
5.2.3. Encapsulation in IPv6 Options . . . . . . . . . . . . 15
5.2.4. Encapsulation in SRv6 SRH . . . . . . . . . . . . . . 15
6. Security Considerations . . . . . . . . . . . . . . . . . . . 15
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 16
9. Informative References . . . . . . . . . . . . . . . . . . . 16
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Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19
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 and proposes the common DetNet data
fields and option including Deterministic Latency Option and
Aggregation Option. The common DetNet options 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
This document uses the following abbreviations:
EDP: DetNet Enhanced Data Plane
IPv6: Internet Protocol version 6
SRH: Segment Routing Header
SRv6: Segment Routing for IPv6 forwarding plane
CQF: Cyclic Queuing and Forwarding
TCQF: Tagged CQF
TQF: Timeslot Queuing and Forwarding
C-SCORE: Work Conserving Stateless Core Fair Queuing
N-SCORE: Non-work Conserving Stateless Core Fair Queuing
PIFO: Push-In First-Out
EDF: Earliest Deadline First
TAS: Time Aware Shaper
ATS: Asynchronous Traffic Shaping
TSN: Time-Sensitive Networking
gLBF:guaranteed Latency Based Forwarding
MNA: MPLS Network Actions
3. Specific Metadata for DetNet Enhanced Data Plane
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3.1. 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.
For the scaling networks which have 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 Enhanced Data Plane (EDP) such as
C-SCORE [I-D.joung-detnet-stateless-fair-queuing], TQF
[I-D.ietf-detnet-packet-timeslot-mechanism], EDF
[I-D.ietf-detnet-deadline-based-forwarding], TCQF
[I-D.ietf-detnet-tcqf], gLBF [I-D.ietf-detnet-glbf], N-SCORE
[I-D.ietf-detnet-nscore] and PIFO
[I-D.ietf-detnet-ontime-forwarding].
And when the queuing mechanisms are used in large-scale networks, the
per-flow states can not be maintained due to 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
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
document 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.
3.2. Aggregation-based Metadata
As per [RFC8655], the DetNet data plane SHOULD 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
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according to 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.
4. Data Fields for DetNet Enhanced Data Plane
4.1. DetNet Options
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
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 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:
Deterministic Latency Option, DetNet-Type is TBD1, as defined in
section 4.2.
Aggregation Option, DetNet-Type is 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. Deterministic Latency Option
The format of Deterministic Latency Option 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Deterministic Latency Type | Flag | Data Len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Deterministic Latency Information ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2 Deterministic Latency Option
Deterministic Latency Type(16 bits): indicates the type of
deterministic latency information with related queuing and scheduling
metadata and it aligned with the suitable categories as defined in
[I-D.ietf-detnet-dataplane-taxonomy] and shown in Figure 3.
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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 3 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
Information 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.
4.2.1. Data Fields 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. An
example of this queuing solution is EDF
[I-D.ietf-detnet-deadline-based-forwarding].
When the type is set to 0x0001, indicates the queuing and scheduling
solutions in right-bounded category. The data fields 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 time bound |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4 Data Fields in Right-bounded Category
Maximum time bound: 32bits, indicates the required maximum time bound
of a packet.
4.2.2. Date Fields 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. An example of this queuing solution is
TQF [I-D.ietf-detnet-packet-timeslot-mechanism].
When the type is set to 0x0002, indicates the queuing and scheduling
solutions in flow level periodic bounded category. The data fields
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 5 Data Fields in Flow Level Periodic Bounded Category
Timeslot ID: indicates the identifier of the timeslot scheduled for a
flow.
4.2.3. Date Fields 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. An example of this queuing
solution is TCQF [I-D.ietf-detnet-tcqf].
When the type is set to 0x0003, indicates the queuing and scheduling
solutions in class level periodic bounded category. The data fields
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Cycle ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6 Data Fields in Class Level Periodic Bounded Category
Cycle ID (32bits): indicates the identifier which the queue applied
for a node to forward DetNet flows within a class level.
4.2.4. Date Fields 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. An example of this queuing
solution is PIFO [I-D.ietf-detnet-ontime-forwarding].
When the type is set to 0x0004, indicates the queuing and scheduling
solutions in flow level non-periodic bounded category The data fields
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 7 Data Fields 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.
4.2.5. Date Fields 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. An example of this queuing solution is
gLBF [I-D.ietf-detnet-glbf].
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When the type is set to 0x0005, indicates the queuing and scheduling
solutions in class level non-periodic bounded category. The data
fields 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 8 Data Fields in Class Level Non-periodic Bounded Category
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.
4.2.6. Date Fields 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. An example of this
queuing solution is C-SCORE
[I-D.joung-detnet-stateless-fair-queuing].
When the type is set to 0x0006, indicates the queuing and scheduling
solutions in flow level rate based unbounded category. The data
fields 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 9 Data Fields in Flow Level Rate-based Unbounded Category
Maximum packet size: 32 bits, indicates the maximum packet size of a
flow.
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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.
4.2.7. Date Fields 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. An
example of this queuing solution is N-SCORE [I-D.ietf-detnet-nscore].
When the type is set to 0x0007, indicates the queuing and scheduling
solutions in flow level Rate based left-bounded category. The data
fields 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Eligible time |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 10 Data Fields 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.
4.3. Aggregation Option
The format of Aggregation Option is shown in Figure 11.
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Aggregation Level | Flag |E| Data Len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Aggregation ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| End-to-end Delay Budget |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| End-to-end Delay Variation Budget |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 11 Aggregation Option
Aggregation Level (16 bits): indicates the aggregation level of
packet treatment ensuring the deterministic latency as Figure 12
shown. This level can also indicate the aggregated class.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Value | Aggregation Level |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|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 12 Aggregation Level
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.
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.
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End-to-end Delay Variation Budget: 32bits. It provides the value of
end-to-end delay variation budget for the aggregated 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 metadata 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.
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. The mapping from
DSCP and the metadata such as queuing information MUST be provided in
the controller plane.
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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 such as
the DetNet options defined in this document and the definition of
these options are independent from the encapsulating protocols. The
data fields could be encapsulated into a variety of protocols and
headers, such as MPLS MNA, IPv6 options and SRv6 SRH in following
sections.
5.2.2. Encapsulation in MPLS MNA
[I-D.ietf-mpls-mna-detnet] specifies formats and mechanisms for MPLS
In-Stack and Post-Stack MNA carrying DetNet-specific metadata such as
such as flow identification and latency information. The DetNet
Deterministic Latency Option as defined in section 4.2 can be
inserted to the Ancillary Data with NAS-2 indicating the latency
information. The DetNet Aggregation Option as defined in section 4.3
can be inserted to the Ancillary Data when NAS-3 indicates the flow
identification information.
5.2.3. Encapsulation in IPv6 Options
The DetNet-specific metadata could also be encapsulated in IPv6
options such as the Hop-by-Hop Options and Destination Options. As
per {I-D.xiong-detnet-6man-queuing-option}}, the DetNet Deterministic
Latency Option can be carried in an IPv6 Hop-by-Hop Option, that all
DetNet forwarding nodes can use the queuing information to achieve
the packet forwarding and scheduling. The DetNet Deterministic
Latency Option can also be carried in an IPv6 Destination Option,
that the DetNet forwarding nodes among SRv6 segment list can use the
queuing-based information to achieve the packet forwarding and
scheduling.
5.2.4. Encapsulation in SRv6 SRH
The DetNet-specific metadata could also be encapsulated in SRv6 SRH.
As per {I-D.xiong-detnet-spring-srh-extensions}}, the DetNet
Deterministic Latency Option can be carried in SRH segment list,
which enables the ability of SRv6 networks to forward a DetNet flow
per segment list.
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.
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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 Deterministic Latency Option
TBD2: DetNet Aggregation Option
8. Acknowledgements
The authors would like to acknowledge Peng Liu, Bin Tan and Shaofu
Peng for their thorough review and very helpful comments.
9. Informative References
[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-05, 8
January 2026, <https://datatracker.ietf.org/doc/html/
draft-ietf-detnet-dataplane-taxonomy-05>.
[I-D.ietf-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-ietf-detnet-deadline-
based-forwarding-00, 16 January 2026,
<https://datatracker.ietf.org/doc/html/draft-ietf-detnet-
deadline-based-forwarding-00>.
[I-D.ietf-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-ietf-
detnet-glbf-00, 16 January 2026,
<https://datatracker.ietf.org/doc/html/draft-ietf-detnet-
glbf-00>.
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[I-D.ietf-detnet-nscore]
Ryoo, Y. and J. Joung, "On-time Forwarding with Non-work
Conserving Stateless Core Fair Queuing", Work in Progress,
Internet-Draft, draft-ietf-detnet-nscore-00, 23 January
2026, <https://datatracker.ietf.org/doc/html/draft-ietf-
detnet-nscore-00>.
[I-D.ietf-detnet-ontime-forwarding]
Ryoo, Y., "On-time Forwarding with Push-In First-Out
(PIFO) queue", Work in Progress, Internet-Draft, draft-
ietf-detnet-ontime-forwarding-00, 23 January 2026,
<https://datatracker.ietf.org/doc/html/draft-ietf-detnet-
ontime-forwarding-00>.
[I-D.ietf-detnet-packet-timeslot-mechanism]
Peng, S., Liu, P., Basu, K., Liu, A., Yang, D., Peng, G.,
and J. Zhao, "Timeslot Queueing and Forwarding Mechanism",
Work in Progress, Internet-Draft, draft-ietf-detnet-
packet-timeslot-mechanism-00, 16 January 2026,
<https://datatracker.ietf.org/doc/html/draft-ietf-detnet-
packet-timeslot-mechanism-00>.
[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>.
[I-D.ietf-detnet-tcqf]
Eckert, T. T., Li, Y., Bryant, S., Malis, A. G., Ryoo, J.,
Liu, P., Li, G., and S. Ren, "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-ietf-
detnet-tcqf-00, 16 January 2026,
<https://datatracker.ietf.org/doc/html/draft-ietf-detnet-
tcqf-00>.
[I-D.ietf-mpls-mna-detnet]
Song, X., Mirsky, G., Varga, B., Gandhi, R., and Q. Xiong,
"MPLS Network Action for Deterministic Networking", Work
in Progress, Internet-Draft, draft-ietf-mpls-mna-detnet-
00, 7 January 2026,
<https://datatracker.ietf.org/doc/html/draft-ietf-mpls-
mna-detnet-00>.
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[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-07, 20 February 2026,
<https://datatracker.ietf.org/doc/html/draft-joung-detnet-
stateless-fair-queuing-07>.
[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>.
[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-03, 14 October 2025,
<https://datatracker.ietf.org/doc/html/draft-xiong-detnet-
flow-aggregation-03>.
[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>.
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[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>.
[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: [email protected]
Aihua Liu
ZTE Corporation
Email: [email protected]
Jinoo Joung
Sangmyung University
Email: [email protected]
Rakesh Gandhi
Cisco Systems, Inc.
Email: [email protected]
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Dong Yang
Beijing Jiaotong University
Email: [email protected]
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