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Carrying 5G Network Slice Identifiers in IP Headers for QoS Assurance Beyond the 3GPP-Managed Domain
draft-zdz-teas-5g-slice-ipextension-00

Document Type Active Internet-Draft (individual)
Authors Cheng Zhou , Jie Dong , Guangyu Zhao
Last updated 2026-07-06
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draft-zdz-teas-5g-slice-ipextension-00
TEAS Working Group                                               C. Zhou
Internet-Draft                                              China Mobile
Intended status: Informational                                   J. Dong
Expires: 7 January 2027                              Huawei Technologies
                                                                 G. Zhao
                                                            China Mobile
                                                             6 July 2026

 Carrying 5G Network Slice Identifiers in IP Headers for QoS Assurance
                     Beyond the 3GPP-Managed Domain
                 draft-zdz-teas-5g-slice-ipextension-00

Abstract

   3GPP defines 5G network slicing as an end-to-end service spanning the
   Radio Access Network (RAN), Transport Network (TN), and Core Network
   (CN).  Within these domains, dedicated slice-awareness and management
   mechanisms are specified by 3GPP.  However, when 5G slice traffic
   traverses an IP backbone network that lies outside the 3GPP-managed
   domain -- such as when a User Plane Function (UPF) connects to an
   external service provider network -- slice context information is
   lost, and the IP backbone cannot differentiate or assure the quality
   of individual slices.

   This document proposes a method for preserving 5G network slice
   awareness in IP backbone networks by encoding the 3GPP Single Network
   Slice Selection Assistance Information (S-NSSAI) directly into IPv6
   packet headers.  This document also describes the associated
   procedures for slice-aware QoS assurance in the IP backbone.

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 RFC
   2119 [RFC2119].

Status of This Memo

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

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

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   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 7 January 2027.

Copyright Notice

   Copyright (c) 2026 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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   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Conventions and Terminology . . . . . . . . . . . . . . . . .   4
     2.1.  Definitions . . . . . . . . . . . . . . . . . . . . . . .   4
     2.2.  Abbreviations . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Problem Statement . . . . . . . . . . . . . . . . . . . . . .   5
     3.1.  5G End-to-End Slice Architecture  . . . . . . . . . . . .   5
     3.2.  The IP Backbone Gap . . . . . . . . . . . . . . . . . . .   6
   4.  Relationship to Existing IETF Network Slice Work  . . . . . .   6
     4.1.  Relationship to RFC 9543  . . . . . . . . . . . . . . . .   7
     4.2.  Relationship to
           draft-ietf-teas-5g-network-slice-application  . . . . . .   7
     4.3.  Complementary Scope . . . . . . . . . . . . . . . . . . .   8
   5.  Solution Overview . . . . . . . . . . . . . . . . . . . . . .   9
   6.  Encoding S-NSSAI in IP Packet Headers . . . . . . . . . . . .   9
   7.  Slice-Aware QoS Assurance in the IP Backbone  . . . . . . . .   9
     7.1.  Control Plane Procedures  . . . . . . . . . . . . . . . .  10
     7.2.  Data Plane Procedures . . . . . . . . . . . . . . . . . .  10
     7.3.  End-to-End Slice Assurance Flow . . . . . . . . . . . . .  10
   8.  Deployment Considerations . . . . . . . . . . . . . . . . . .  11
     8.1.  Incremental Deployment  . . . . . . . . . . . . . . . . .  11
     8.2.  Applicability to Service Provider Networks  . . . . . . .  12
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .  12
   10. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  12
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .  12
     11.1.  Normative References . . . . . . . . . . . . . . . . . .  12

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     11.2.  Informative References . . . . . . . . . . . . . . . . .  12
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  13

1.  Introduction

   5G network slicing, as defined by the 3rd Generation Partnership
   Project (3GPP) [TS23.501], enables multiple logical networks to
   coexist over a shared physical infrastructure, each tailored to
   specific service characteristics.  Each slice is identified by an
   S-NSSAI (Single Network Slice Selection Assistance Information) and
   is associated with a set of Service Level Agreements (SLAs) covering
   parameters such as throughput, latency, and packet loss rate.

   The 3GPP end-to-end slice architecture spans the Radio Access Network
   (RAN), the Transport Network (TN), and the Core Network (CN).  Within
   these domains, 3GPP and IETF have jointly developed mechanisms for
   slice awareness and traffic differentiation.  In particular,
   [RFC9543] provides a framework for IETF Network Slices using
   technologies such as L2VPN, L3VPN, and Segment Routing, while
   [I-D.ietf-teas-5g-network-slice-application] describes the mapping
   between 3GPP network slice parameters and IETF Network Slice Service
   models.

   However, 5G slice traffic frequently traverses networks that lie
   outside the 3GPP-managed domain.  A representative example is the IP
   backbone network connecting the 5G Core's User Plane Function (UPF)
   to external service provider networks.  When a 5G slice packet exits
   the UPF and enters the IP backbone, it carries no slice
   identification information recognizable by IP-layer devices.  The IP
   backbone therefore treats all 5G traffic uniformly, unable to apply
   per-slice QoS policies or resource guarantees.

   This document addresses this gap by defining a method to encode the
   S-NSSAI directly into IP packet headers, enabling routers in the IP
   backbone to identify the originating 5G slice and apply corresponding
   QoS assurance policies.  The method is designed with the following
   properties in mind:

   *  Backward compatibility: devices that do not implement this
      specification can safely ignore the new option fields without
      disrupting forwarding.

   *  Incremental deployability: only selected ingress and egress nodes
      in the IP backbone need to be upgraded; core transit nodes may
      remain unchanged, or optionally be upgraded on demand.

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   *  Extensibility: the encoding is self-contained and does not
      preclude the concurrent use of other IP options or extension
      headers.

   This document is informational in nature.  It does not specify a
   mandatory protocol behavior but rather describes a technical approach
   intended to stimulate discussion within the IETF community on
   extending 5G slice awareness beyond the 3GPP-managed domain.

2.  Conventions and Terminology

2.1.  Definitions

   This document uses the following terms:

   IP Backbone Network: A packet-switched network, based on IP
   technology, that lies outside the 3GPP-managed domain and provides
   interconnectivity between the 5G Core and external service provider
   networks.  It is operated independently from the 3GPP RAN, TN, and
   CN, and does not natively implement 3GPP network slice management
   functions.

   Slice-Aware Node: A router or forwarding device in the IP backbone
   that has been upgraded to parse and act upon the S-NSSAI encoded in
   IP packet headers as defined in this document.

   Slice-Unaware Node: A router or forwarding device that does not
   implement the mechanisms defined in this document and forwards
   packets according to existing IP forwarding rules.

   Ingress UPF: The User Plane Function (UPF) at the boundary between
   the 5G Core and the IP backbone, responsible for encoding the S-NSSAI
   into outbound IP packets.

   Service Provider Server: A server operated by an external service
   provider that terminates 5G slice traffic.  For downlink traffic, it
   is responsible for encoding the S-NSSAI into IP packets destined for
   the 5G Core.

   This document also uses terms as defined in [RFC9543] and
   [I-D.ietf-teas-5g-network-slice-application].

2.2.  Abbreviations

   BOSS: Business and Operations Support System

   CN: Core Network

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   CSMF: Communication Service Management Function

   NSC: Network Slice Controller

   RAN: Radio Access Network

   SD: Slice Differentiator

   SDP: Service Demarcation Point

   SLA: Service Level Agreement

   SLO: Service Level Objective

   SLE: Service Level Expectation

   S-NSSAI: Single Network Slice Selection Assistance Information

   SST: Slice/Service Type

   TN: Transport Network

   UE: User Equipment

   UPF: User Plane Function

3.  Problem Statement

3.1.  5G End-to-End Slice Architecture

   The 3GPP end-to-end 5G network slice architecture [TS23.501]
   [TS28.530] encompasses the RAN, TN, and CN.  A 5G Network Slice
   Instance (NSI) is identified by an S-NSSAI composed of a Slice/
   Service Type (SST) field (8 bits) and an optional Slice
   Differentiator (SD) field (24 bits), as illustrated below.

                          +---------+-----------+
                          |   SST   |     SD    |
                          | (8 bits)| (24 bits) |
                          +---------+-----------+
                          <-------- S-NSSAI ---->

                  Figure 1: S-NSSAI Format (32-bit total)

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   The SST field takes values in the range 0-255, where values 0-127 are
   reserved for standardized slice types and values 128-255 may be
   operator-defined.  The SD field is operator-defined and distinguishes
   multiple slices of the same service type.  The S-NSSAI is unique
   within a Public Land Mobile Network (PLMN).

   Within the 3GPP-managed domain, each network function has access to
   the S-NSSAI associated with a given session and can enforce per-slice
   policies accordingly.  The Transport Network within this domain may
   additionally use IETF-defined mechanisms (e.g., those described in
   [RFC9543]) to provide slice-differentiated connectivity with
   committed SLOs.

3.2.  The IP Backbone Gap

   In several important deployment scenarios, 5G slice traffic must
   traverse an IP backbone network that is not part of the 3GPP-managed
   domain.  This network operates under its own administrative domain
   and its devices are not configured with 3GPP slice management
   functions.

   The following figure illustrates the topology:

      +------+  +-----+  +----+  +-----+  +-----+
      |  UE  |--| RAN |--| TN |--| CN  |--|     |
      +------+  +-----+  +----+  +-----+  | UPF |
                                          |     |
                                          +--+--+       +----------+
                                             |          | Service  |
                                  +----------+------+   | Provider |
                                  |  IP Backbone Nw |-- | Servers  |
                                  |  (outside 3GPP) |   +----------+
                                  +-----------------+

           Figure 2: 5G Slice Traffic Traversing the IP Backbone

   When a slice packet departs the UPF and enters the IP backbone, the
   S-NSSAI -- which is carried in 3GPP control plane signaling and
   encoded in domain-internal identifiers (such as VLAN IDs or GTP-U
   TEID) -- is no longer present in a form recognizable by standard IP
   routers.  The IP backbone therefore cannot determine the slice
   membership of a packet and is unable to apply differentiated
   forwarding or QoS policies on a per-slice basis.

4.  Relationship to Existing IETF Network Slice Work

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4.1.  Relationship to RFC 9543

   [RFC9543] defines the framework for IETF Network Slices in networks
   built from IETF technologies.  It establishes the concept of IETF
   Network Slice Services -- characterized by a set of Service
   Demarcation Points (SDPs), connectivity constructs, and associated
   SLOs and SLEs -- and introduces the IETF Network Slice Controller
   (NSC) as the management and orchestration component.

   [RFC9543] and the present document address complementary but distinct
   scopes.  [RFC9543] focuses on the connectivity within the provider-
   managed network domain, where an NSC can configure network resources
   and enforce SLOs using mechanisms such as L3VPN, Segment Routing
   Traffic Engineering, or Enhanced VPN.  In this model, the S-NSSAI is
   not directly visible in the data plane; instead, the NSC translates
   slice service requests into domain-local resource commitments, as
   described in [RFC9889].

   The present document addresses the complementary case: traffic that
   exits the 3GPP-managed domain entirely and traverses an IP backbone
   that may not be under the control of any NSC.  In this environment,
   domain-local identifiers (such as VLANs or MPLS labels configured by
   the NSC) are absent, and there is no NSC to enforce per-slice
   policies on individual routers.  The proposed mechanism of encoding
   S-NSSAI in IP headers directly provides the identification signal
   that enables IP backbone nodes to perform slice-aware forwarding
   without requiring integration with a 3GPP or IETF network slice
   management system.

   The two approaches are compatible and can coexist.  An operator may
   deploy [RFC9543]-based mechanisms for the Transport Network segment
   within the 3GPP domain and the S-NSSAI-in-IP-header mechanism defined
   in this document for the IP backbone segment beyond the 3GPP domain.
   The UPF serves as the demarcation point where the two approaches
   meet: on the 3GPP side, the slice is identified through 3GPP and IETF
   Network Slice mechanisms; on the IP backbone side, the S-NSSAI is
   encoded in the IP packet header.

4.2.  Relationship to draft-ietf-teas-5g-network-slice-application

   [I-D.ietf-teas-5g-network-slice-application] describes the
   application of the IETF Network Slice framework ([RFC9543]) to 3GPP
   5G end-to-end network slices.  It specifies how 3GPP slice parameters
   -- primarily derived from the EP_Transport Information Object Class
   (IOC) defined in [TS28.541] -- are mapped to IETF Network Slice
   Service parameters expressed in the IETF Network Slice NBI YANG data
   model [I-D.ietf-teas-ietf-network-slice-nbi-yang].  The document
   covers management- and control-plane mapping procedures, as well as

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   data-plane encoding options including VLAN, MPLS/SR-MPLS, SRv6,
   Policy-Based Routing, and UDP source port-based methods.

   The data-plane encoding methods discussed in
   [I-D.ietf-teas-5g-network-slice-application] apply within the 3GPP-
   managed Transport Network segment.  They encode slice context using
   network-local identifiers that are meaningful within the
   administrative domain of the transport provider.  These identifiers
   (such as VLAN IDs or SR SIDs) are allocated by the transport
   provider's NSC and do not persist beyond the provider network
   boundary.

   The present document is distinct in that it defines a mechanism for
   encoding the globally unique S-NSSAI identifier -- rather than a
   network-local surrogate -- directly into the IP packet header.  This
   mechanism is intended for use on the IP backbone segment that lies
   outside the transport provider's administrative domain, where
   network-local identifiers allocated by an NSC are not available.

   Furthermore, the Gap Analysis section of
   [I-D.ietf-teas-5g-network-slice-application] identifies that 3GPP
   EP_Transport IOC information is insufficient for fully instructing
   the IETF NSC in all deployment cases, particularly for virtualized
   network functions.  The present document approaches a related
   challenge -- the absence of slice context on the IP backbone --
   through a complementary data-plane mechanism that does not rely on
   management-plane coordination between 3GPP and IETF systems.

4.3.  Complementary Scope

   The relationship between this document and the existing IETF slicing
   work can be summarized in terms of network segments:

   UE -> RAN -> [Transport Network] -> CN/UPF -> [IP Backbone] -> Server
                        |                                |
            Addressed by RFC 9543,              Addressed by this
            RFC 9889, and                       document
            draft-5g-ns-app

                     Figure 3: complementary scope

   The method described in this document is explicitly designed to
   operate at and beyond the UPF egress boundary.  It does not replace
   or modify any mechanism used within the IETF Network Slice framework;
   it extends the observable slice context into a network segment where
   that framework does not currently reach.

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5.  Solution Overview

   The proposed solution comprises three functional components, which
   together extend 5G network slice awareness into the IP backbone
   network.

   The first component is the encoding of the S-NSSAI into outbound IP
   packet headers.  For uplink traffic (from the 5G Core toward the
   service provider network), the UPF encodes the S-NSSAI of the
   associated session into the IP header of each packet before
   forwarding it to the IP backbone.  For downlink traffic (from the
   service provider network toward the 5G Core), the service provider
   server encodes the S-NSSAI into the IP header of packets that it
   transmits into the IP backbone.  The S-NSSAI value used by the
   service provider server is obtained through a prior service
   subscription or provisioning exchange with the mobile network
   operator.

   The second component is the specific encoding format for the S-NSSAI
   in IPv6 headers.  The encoding uses the Hop-by-Hop Options extension
   header, carrying the full 32-bit S-NSSAI value.  The detailed formats
   are specified in Section 6.

   The third component is the slice-aware QoS assurance mechanism in the
   IP backbone.  The IP backbone management system obtains the SLA
   requirements for each 5G slice from the operator's management systems
   and configures corresponding QoS policies on slice-aware forwarding
   devices.  When a slice-aware node receives a packet carrying a Slice
   ID option, it extracts the S-NSSAI value, looks up the corresponding
   QoS policy, and applies the appropriate forwarding treatment.  The
   QoS enforcement mechanisms themselves (such as priority scheduling,
   traffic shaping, or traffic engineering) are outside the scope of
   this document and may be selected from existing IP QoS techniques.

6.  Encoding S-NSSAI in IP Packet Headers

   Since the IETF is no longer developing new extensions for IPv4, this
   draft does not consider schemes that carry S-NSSA information within
   IPv4 packets. . This option, referred to as the "Slice ID Option",
   carries the full 32-bit S-NSSAI value.

   IPv6 extension headers can be designed based on the
   [I-D.ietf-6man-enhanced-vpn-vtn-id]draft-ietf-6man-enhanced-vpn-vtn-
   id draft, utilizing the "Context Type" field to define an N:1 or 1:1
   mapping from N-SSAID to NRP ID.

7.  Slice-Aware QoS Assurance in the IP Backbone

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7.1.  Control Plane Procedures

   The IP backbone management system coordinates with the mobile network
   operator's management infrastructure to obtain the SLA requirements
   associated with each active 5G network slice.  This coordination is
   performed through existing inter-system interfaces, such as those
   provided by the operator's Business and Operations Support System
   (BOSS), using the Communication Service Management Function (CSMF) as
   an intermediary when applicable.

   For each active slice, the management system retrieves the relevant
   SLA parameters, which may include committed throughput (uplink and
   downlink), maximum one-way latency, maximum jitter, and maximum
   packet loss rate.  These parameters correspond to the SLO constructs
   defined in Section 5.1 of [RFC9543].  Based on the retrieved SLA
   parameters, the management system generates QoS policies indexed by
   S-NSSAI value and distributes these policies to Slice-Aware Nodes in
   the IP backbone using applicable network management interfaces.

7.2.  Data Plane Procedures

   Upon receiving an IP packet, a Slice-Aware Node performs the
   following sequence of operations.  It first inspects the packet for
   the presence of a Slice ID Option, as defined in Section 6.  If a
   Slice ID Option is present, the node extracts the 32-bit S-NSSAI
   value and uses it as a lookup key in the locally installed QoS policy
   table.  If a matching policy entry is found, the node applies the
   corresponding forwarding treatment (such as queue selection, traffic
   marking, or rate limiting) to the packet.  If no Slice ID Option is
   present, or if no matching policy is found, the node forwards the
   packet according to its default IP forwarding behavior.

   A Slice-Unaware Node forwards all packets according to default IP
   forwarding rules.  The presence of an unrecognized option in an IPv6
   packet does not cause forwarding failure on such nodes, by virtue of
   the option processing rules defined in [RFC8200].

7.3.  End-to-End Slice Assurance Flow

   The following sequence describes the complete operational flow for
   uplink traffic (UE to service provider server):

   *  At slice instantiation time, the 3GPP Core Network Slice Subnet
      Management Function (CN-NSSMF) provisions the UPF with the mapping
      between the VLAN ID (or other access-side identifier) and the
      corresponding S-NSSAI value.

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   *  The service provider establishes a subscription agreement with the
      mobile network operator for one or more named slices.  As part of
      this agreement, the service provider obtains the S-NSSAI values
      identifying each subscribed slice.

   *  When the UPF receives an uplink packet from the 5G Core, it
      determines the S-NSSAI associated with the packet's session using
      the locally maintained mapping table.  The UPF then encodes this
      S-NSSAI into the IP packet header according to Section 6 and
      forwards the packet into the IP backbone.

   *  The IP backbone management system has previously configured Slice-
      Aware Nodes with per-S-NSSAI QoS policies based on SLA parameters
      obtained from the operator's management system.  As the packet
      traverses the IP backbone, Slice-Aware Nodes extract the S-NSSAI
      from the packet and apply the corresponding QoS treatment.

   *  For downlink traffic, the service provider's server encodes the
      appropriate S-NSSAI into the IP packet header before transmitting
      into the IP backbone, enabling the same per-slice QoS treatment
      for return traffic.

8.  Deployment Considerations

8.1.  Incremental Deployment

   A significant practical advantage of the proposed mechanism is that
   it supports incremental deployment.  Not all nodes in the IP backbone
   need to be upgraded to support slice-aware processing.  An operator
   can selectively upgrade ingress and egress nodes -- specifically, the
   UPF-facing border routers and the service-provider-facing border
   routers -- while leaving core transit nodes unchanged.

   In this configuration, the border nodes apply per-slice QoS marking
   (e.g., DSCP remarking) based on the extracted S-NSSAI, and core
   transit nodes perform standard DSCP-based differentiated service
   forwarding without needing to process the Slice ID Option directly.
   This allows the deployment to leverage the existing DiffServ
   infrastructure of the IP backbone while extending per-slice awareness
   to the network boundaries.

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8.2.  Applicability to Service Provider Networks

   The slice identification mechanism defined in this document is not
   limited to the IP backbone between the UPF and external service
   providers.  The same encoding approach is applicable within service
   provider networks (such as enterprise data center networks or content
   delivery networks) that wish to maintain per-slice traffic
   differentiation for 5G services terminating at their servers.  In
   such deployments, the service provider's ingress gateway would be
   configured to recognize the S-NSSAI encoded in incoming IP packets
   and apply appropriate internal forwarding policies.

9.  Security Considerations

   (TBD)

10.  IANA Considerations

   The required IANA will be coverd by
   [I-D.ietf-6man-enhanced-vpn-vtn-id].  This document does not require
   any new IANA actions.

11.  References

11.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC8200]  Deering, S. and R. Hinden, "Internet Protocol, Version 6
              (IPv6) Specification", STD 86, RFC 8200,
              DOI 10.17487/RFC8200, July 2017,
              <https://www.rfc-editor.org/info/rfc8200>.

11.2.  Informative References

   [I-D.ietf-6man-enhanced-vpn-vtn-id]
              Dong, J., Li, Z., Xie, C., Ma, C., and G. S. Mishra,
              "Carrying Network Resource (NR) related Information in
              IPv6 Extension Headers", Work in Progress, Internet-Draft,
              draft-ietf-6man-enhanced-vpn-vtn-id-16, 10 June 2026,
              <https://datatracker.ietf.org/doc/html/draft-ietf-6man-
              enhanced-vpn-vtn-id-16>.

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   [I-D.ietf-teas-5g-network-slice-application]
              Geng, X., Contreras, L. M., Rokui, R., Dong, J., and I.
              Bykov, "IETF Network Slice Application in 3GPP 5G End-to-
              End Network Slice", Work in Progress, Internet-Draft,
              draft-ietf-teas-5g-network-slice-application-07, 6 July
              2026, <https://datatracker.ietf.org/doc/html/draft-ietf-
              teas-5g-network-slice-application-07>.

   [I-D.ietf-teas-ietf-network-slice-nbi-yang]
              Wu, B., Dhody, D., Rokui, R., Saad, T., and J. Mullooly,
              "A YANG Data Model for the RFC 9543 Network Slice
              Service", Work in Progress, Internet-Draft, draft-ietf-
              teas-ietf-network-slice-nbi-yang-26, 26 May 2026,
              <https://datatracker.ietf.org/doc/html/draft-ietf-teas-
              ietf-network-slice-nbi-yang-26>.

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

   [RFC9889]  Szarkowicz, K., Ed., Roberts, R., Ed., Lucek, J.,
              Boucadair, M., Ed., and LM. Contreras, "A Realization of
              Network Slices for 5G Networks Using Current IP/MPLS
              Technologies", RFC 9889, DOI 10.17487/RFC9889, November
              2025, <https://www.rfc-editor.org/info/rfc9889>.

   [TS23.501] 3GPP, "System architecture for the 5G System (5GS)", 3GPP
              TS 23.501, 2024, <https://www.3gpp.org/ftp/Specs/
              archive/23_series/23.501/>.

   [TS28.530] 3GPP, "Management and orchestration of networks and
              network slicing", 3GPP TS 28.530, 2024,
              <https://www.3gpp.org/ftp/Specs/
              archive/28_series/28.530/>.

   [TS28.541] 3GPP, "Management and orchestration; 5G Network Resource
              Model (NRM)", 3GPP TS 28.541, 2024,
              <https://www.3gpp.org/ftp/Specs/
              archive/28_series/28.541/>.

Authors' Addresses

Zhou, et al.             Expires 7 January 2027                [Page 13]
Internet-Draft      Carry 5G Slice ID in IP Backbone           July 2026

   Cheng Zhou
   China Mobile
   Beijing
   100053
   China
   Email: zhouchengyjy@chinamobile.com

   Jie Dong
   Huawei Technologies
   Beijing
   100095
   China
   Email: jie.dong@huawei.com

   Guangyu Zhao
   China Mobile
   Beijing
   100053
   China
   Email: zhaoguangyu@chinamobile.com

Zhou, et al.             Expires 7 January 2027                [Page 14]