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Static Context Header Compression (SCHC) Architecture
draft-ietf-schc-architecture-05

Document Type Active Internet-Draft (schc WG)
Authors Alexander Pelov , Pascal Thubert , Ana Minaburo
Last updated 2025-10-17
Replaces draft-ietf-lpwan-architecture
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draft-ietf-schc-architecture-05
SCHC Working Group                                              A. Pelov
Internet-Draft                                            IMT Atlantique
Intended status: Informational                                P. Thubert
Expires: 20 April 2026                                                  
                                                             A. Minaburo
                                                              Consultant
                                                         17 October 2025

         Static Context Header Compression (SCHC) Architecture
                    draft-ietf-schc-architecture-05

Abstract

   This document defines the SCHC architecture.

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
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   This Internet-Draft will expire on 20 April 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
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   Please review these documents carefully, as they describe your rights
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   provided without warranty as described in the Revised BSD License.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Requirements Language . . . . . . . . . . . . . . . . . . . .   3
   3.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Building Blocks . . . . . . . . . . . . . . . . . . . . . . .   4
     4.1.  SCHC Stratum (plural: strata) . . . . . . . . . . . . . .   4
     4.2.  Discriminator . . . . . . . . . . . . . . . . . . . . . .   5
     4.3.  SCHC Control End-Point  . . . . . . . . . . . . . . . . .   6
       4.3.1.  SCHC Control Header . . . . . . . . . . . . . . . . .   7
     4.4.  SCHC Data End-Point . . . . . . . . . . . . . . . . . . .   8
       4.4.1.  SCHC Data Header  . . . . . . . . . . . . . . . . . .   9
     4.5.  SCHC Profiles . . . . . . . . . . . . . . . . . . . . . .  10
     4.6.  SCHC Operation  . . . . . . . . . . . . . . . . . . . . .  10
       4.6.1.  SCHC Rules  . . . . . . . . . . . . . . . . . . . . .  11
       4.6.2.  SoR identification  . . . . . . . . . . . . . . . . .  11
     4.7.  SCHC Management . . . . . . . . . . . . . . . . . . . . .  11
       4.7.1.  SCHC Instance Manager . . . . . . . . . . . . . . . .  12
       4.7.2.  SCHC Data Model . . . . . . . . . . . . . . . . . . .  12
   5.  SCHC Architecture . . . . . . . . . . . . . . . . . . . . . .  14
   6.  The Static Context Header Compression . . . . . . . . . . . .  17
     6.1.  SCHC over Network Technologies  . . . . . . . . . . . . .  18
       6.1.1.  SCHC over PPP . . . . . . . . . . . . . . . . . . . .  19
       6.1.2.  SCHC over Ethernet  . . . . . . . . . . . . . . . . .  20
       6.1.3.  SCHC over IPv6  . . . . . . . . . . . . . . . . . . .  20
       6.1.4.  SCHC over UDP . . . . . . . . . . . . . . . . . . . .  21
   7.  SCHC Endpoints for LPWAN Networks . . . . . . . . . . . . . .  21
     7.1.  SCHC Device Lifecycle . . . . . . . . . . . . . . . . . .  22
       7.1.1.  Device Development  . . . . . . . . . . . . . . . . .  22
       7.1.2.  Rules Publication . . . . . . . . . . . . . . . . . .  23
       7.1.3.  SCHC Device Deployment  . . . . . . . . . . . . . . .  23
       7.1.4.  SCHC Device Maintenance . . . . . . . . . . . . . . .  23
       7.1.5.  SCHC Device Decommissionning  . . . . . . . . . . . .  24
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  24
   9.  IANA Consideration  . . . . . . . . . . . . . . . . . . . . .  24
   10. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  24
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .  24
     11.1.  Normative References . . . . . . . . . . . . . . . . . .  24
     11.2.  Informative References . . . . . . . . . . . . . . . . .  25
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  27

1.  Introduction

   The IETF LPWAN WG defined the necessary operations to enable IPv6
   over selected Low-Power Wide Area Networking (LPWAN) radio
   technologies. [rfc8376] presents an overview of those technologies.

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   The Static Context Header Compression (SCHC) [rfc8724] technology is
   the core product of the IETF LPWAN working group and was the basis to
   form the SCHC Working Group. [rfc8724] defines a generic framework
   for header compression and fragmentation, based on a static context
   that is pre-installed on the SCHC endpoints.

   This document details the constitutive elements of a SCHC-based
   solution, and how the solution can be deployed.  It provides a
   general architecture for a SCHC deployment, positioning the required
   specifications, describing the possible deployment types, and
   indicating models whereby the rules can be distributed and installed
   to enable reliable and scalable operations.

2.  Requirements Language

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

3.  Terminology

   *  C/D.  Compression and Decompression.

   *  Context.  All the information related to the Rules for a SCHC
      Header operation, which can be either Non-Compression, C/D, F/R,
      or CORECONF_Management.

   *  FID.  Field Identifiers, describing the name of the field in a
      protocol header.

   *  F/R.  Fragmentation and Reassembly.

   *  Rule.  A description of the header fields to performs compression/
      decompression, fragmentation/reassembly, SCHC end-points and
      CORECONF_Management.

   *  SCHC Gateway (end-point).  The SCHC end-point located upstream,
      e.g., in a Network Core Software.

   *  SCHC Device (end-point).  The SCHC end-point located downstream,
      e.g., in a constrained physical device.

   *  SCHC Header.  A SCHC Header contains the information necessary for
      a SCHC operation, e.g., a Rule ID and a residue.  The SCHC Control
      Header transports SCHC's control information whereas the SCHC Data
      Header transports user payload that was processed by SCHC.

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   *  SCHC end-point.  An entity (e.g., Device, Application and Network
      Gateway) involved in the SCHC process.  Each SCHC end-point will
      have its Set of Rules (SoR), based on the profile, the protocols,
      the device, the behaviour and a Set of Variables (SoV).

   *  SCHC Instance.  The session between SCHC end-points in two or more
      peer nodes operating SCHC to communicate using a common SoR and a
      matching SoV.  There are at least two SCHC Instances involved per
      SCHC stratum, one SCHC Control Instance that manages the SCHC
      Control Header to discriminate the SCHC Data Instance(s) and one
      or more SCHC Data Instance(s) that handle(s) the SCHC Data Header,
      for, e.g., compression and decompression operations.

   *  SCHC Instance Manager.  Provides the management of SCHC end-
      points, the SoR of each end-point and the dialog between hosts to
      keep the SCHC synchronization, and the establishment of SCHC
      Instances with peer nodes.

   *  SoR (Set of rules).  Group of Rules used in a SCHC end-point.  The
      set of rules contains Rules for different nature as compression,
      no compression, fragmentation, SCHC end-points and CORECONF
      management.

   *  SoV (Set of Variables).  External information that needs to be
      known to identify the correct protocol, the SCHC Instance id, and
      the flow when there is one.

   *  SCHC Stratum.  A SCHC Stratum is the SCHC analoguous to a
      classical layer in the IP architecture, but its operation may
      cover multiple IP layers or only a subset of a layer.

4.  Building Blocks

   This section specifies the principal blocks defined for building and
   using the SCHC architecture in any network topology and protocol.

4.1.  SCHC Stratum (plural: strata)

   A SCHC Stratum is the SCHC analoguous to a classical layer in the IP
   architecture, but its operation may cover multiple IP layers or only
   a subset of a layer, e.g., IP only, IP+UDP, CoAP, or OSCORE
   [rfc8824].  The term stratum is thus used to avoid confusion with
   traditional layers.  Also, SCHC Strata are not stacked, though they
   can be nested.

   The SCHC Stratum data in a datagram is composed of a SCHC Control
   Header (which may be compressed to the point that it is fully
   implicit and thus elided), a SCHC Data Header (that is used to

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   uncompress a section of the SCHC datagram), and possibly some
   remaining payload that is unaffected by the SCHC Stratum.  The SCHC
   Stratum operation requires at least 2 end-points, one for the SCHC
   Control Header and one or more for the SCHC Data Header.

   A SCHC datagram may contain additional stratum data, to be handled by
   sequential (nested) SCHC Strata, where the inner (nested) Stratum
   operates within the decompressed/reassembled payload of the outter
   (nesting) Stratum.

   A SCHC Stratum is instantiated in participating nodes as a pair of
   SCHC end-points, and matching SCHC end-points in communicating nodes
   are associated to form a SCHC end-point.  A SCHC end-point may be
   Point to point (P2P), or Point to Multipoint.  A P2MP SCHC end-point
   is unidirectional, meaning that all the SCHC datagrams are generated
   by the same node.  A P2P SCHC end-point may be unidirectional or
   bidirectional, symmetrical (between peers) or asymetrical (between a
   device and an application).

   A SCHC end-point operates datagram fragmentation and/or data
   compression and decompression, and maintains the state and timers
   associated with the Stratum operation over the consecutive datagrams
   or fragments.

   The SCHC end-points that handle the compression for nested Strata
   might differ for the same datagram, meaning that the payload of a
   given Stratum might be compressed/uncompressed by a different entity,
   possibly in a different node.  It results that the degree of
   compression (the number of Strata) for a given datagram may vary as
   the datagram progresses through the layers inside a node and then
   through the network.

4.2.  Discriminator

   The key to determine how to decompress a SCHC Control Header in a
   stratum is called a Discriminator.

   The Discriminator is typically extrinsic to the stratum data.

   It may be found in the datagram context, e.g., the ID of the
   interface, VLAN, SSID, or PPP SCHC Instance on which the datagram is
   received.

   It may also be received in the datagram, natively or uncompressed
   from a nesting stratum, e.g.:

   *  A source and destination MAC or IP addresses of the datagram
      carrying SCHC datagrams

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   *  A source and destination port number of the transport layer
      carrying SCHC datagrams

   *  A next header field

   *  An MPLS label

   *  A TLS Association

   *  Any other kind of connection id.

   The Discriminator enables to determine the SCHC end-point that is
   used to decompress the SCHC Control Header, called a SCHC Control
   end-point.

   Once uncompressed, the SCHC Control Header enables to determine the
   SCHC end-point, called a SCHC Data end-point, that is used to restore
   the datagram data that is compressed in the stratum.

4.3.  SCHC Control End-Point

   The SCHC Control end-point manages the SCHC Control Headers and
   provides the information and the selection of a SCHC Data end-point.

   The rules for that end-point might be such that all the fields in the
   SCHC Control Header are well-known, in which case the header is fully
   elided in the stratum data and recreated from the rules.

   The rules might also leverage intrinsic data that is found in-line in
   the stratum data, in which case the first bits of the stratum data
   are effectively residue to the compression of the SCHC Control
   Header.  Finally, the rules may leverage extrinsic data as the
   Discriminator does.

   Figure 1 illustrates the case where a given stratum may compress
   multiple protocols SCHC Instances, each corresponding to a different
   SCHC Data end-point.

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   +---------------+---------------+---------------+ S
   | SCHC Data Hdr | SCHC Data Hdr | SCHC Data Hdr | C
   | end-point___  | end-point___  | end-point___  | H
   |         [SoR] |         [SoR] |         [SoR] | C
   |         [___] |         [___] |         [___] |
   |               |               |               | S
   |               |               |               | T
   +----inst_id1---+----inst_id2---+----inst_id3---+ R
   .              SCHC Stratum end-point     ___   . A
   .                                        [SoR]  . T
   .                                        [___]  . U
   +...............................................+ M
                _____________^
              /
            /
          +-- Discriminator: (SCHC Control Header)(SCHC Data Header)

   Each SCHC Data end-point uses its own Set of Rules,
   but share the same SCHC Control Header.

                  Figure 1: SCHC end-points for a stratum

4.3.1.  SCHC Control Header

   The SCHC Control Header carries information that is required for the
   SCHC strata operation.  For example, it selects the correct end-point
   and checks the validity of the datagram.  There IS NOT always a
   RuleID if there is only one Rule for the SCHC Control Header, whose
   length is 0.  The SCHC Control Header format is not fixed, and the
   SoR MUST have one or more Rules describing the formats.  SCHC Control
   Header contains different fields.  For the end-point, if the SCHC
   Control Header identifies, e.g., the next protocol in the stack, the
   format of the SCHC Control Header may be represented as shown in
   Figure 2.

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   Non-compressed SCHC Control Header Format:
   +- - - - - - - - - +- - - - - - -+- - -+
   | SCHC Instance ID | Protocol ID | CRC |
   +- - - - - - - - - +- - - - - - -+- - -+

   SCHC Control Header Compressed:
   +- - - - -+- - - - - - - - - - +
   | Rule ID | Compressed Residue |
   +- - - - -+- - - - - - - - - - +

   Rule uses to compressed the SCHC Control Header:
   RuleID
   +------------+--+---+--+-----+------+-----------+
   |     FID    |FL|POS|DI| TV  |  MO  |     CDA   |
   +------------+--+---+--+-----+------+-----------+
   | SCHC.sesid |10| 1 |Bi|0x00 |MSB(7)| LSB       |
   | SCHC.proto | 8| 1 |Bi|value|equal | not-sent  |
   | SCHC.CRC   | 8| 1 |Bi|     |ignore| value-sent|
   +------------+--+---+--+-----+------+-----------+

          Figure 2: Example of SCHC Control Header Format and the
                             corresponding Rule

   In this example the Rule defines:

   *  A SCHC InstanceID is 10 bits length and it is used to identify the
      SoR used for this end-point of SCHC.

   *  A Protocol ID in 1-byte length giving the value send in the layer
      below the SCHC datagram to identify the uncompressed protocol
      stack.

   *  And A CRC.  The CRC field is 8 bits length and covers the SCHC
      Control Header and the SCHC datagram from error.  When it is
      elided by the compression, the layer-4 checksum MUST be replaced
      by another validation sequence.

4.4.  SCHC Data End-Point

   A SCHC Data end-point handles this node's side of a SCHC Data
   instance?  It is characterized by a particular SoR common with the
   corresponding distant end-point.  The [rfc8724] defines a protocol
   operation between a pair of peers.  In a SCHC strata, several SCHC
   end-points may contain different SoR.

   When the SCHC Device is a highly constrained unit, there is typically
   only one end-point for that Device, and all the traffic from and to
   the device is exchanged with the same Network Gateway.  All the

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   traffic can thus be implicitly associated with the single end-point
   that the device supports, and the Device does not need to manipulate
   the concept.  For that reason, SCHC avoids to signal explicitly the
   end-point identification in its data datagrams.

   The Network Gateway, on the other hand, maintains multiple end-
   points, one per SCHC Device.  The end-point is derived from the lower
   layer, typically the source of an incoming SCHC datagram as a
   discriminator in the Figure 1.  The end-point is used in particular
   to select the set of rules that apply to the SCHC Device, and the
   current state of their exchange, e.g., timers and previous fragments.

4.4.1.  SCHC Data Header

   As defined in section 5.1 of [rfc8724], a SCHC datagram (or packet)
   is composed of the compressed header called the SCHC Data Header
   followed by the uncompressed remainder payload from the original
   datagram (or packet).  The SCHC Data Header, contains the data
   generated by the SCHC operation.  It is composed of a RuleID followed
   by the content described in the Rule.  The content may be a C/D
   datagram, a F/R datagram, a CORECONF_Management or a Non Compressed
   datagram.

    <------ Compressed Header ------> <- Uncompressed Data ->

   +------------------------------------------------------+
   |                   SCHC Datagram                      |
   +------------------------------------------------------+

   +---------------------------------+--------------------+
   |      SCHC Data Header           |      Payload       |
   +---------------------------------+--------------------+

   +----------+----------------------+--------------------+
   |  RuleID  |    Rule Content      |      Payload       |
   +----------+----------------------+--------------------+

                          Figure 3: SCHC Datagram

   Figure 4 shows the compressed header format that is composed of the
   RuledID and a Compressed Residue, which is the output of compressing
   a datagram header with a Rule.

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   C/D Compressed SCHC Data Header:

   +------------+----------------------+
   |   RuleID   | Compressed Residue   |
   +------------+----------------------+

   F/R Compressed SCHC Data Header:

   +------------+----------------------+--------+--...--+--------+
   |   RuleID   | Fragmentation Header | Tile_1 |       | Tile_n |
   +------------+----------------------+--------+--...--+--------+

   CORECONF_Management SCHC Data Header:

   +------------+----------------------+
   |   RuleID   | Compressed Residue   |
   +------------+----------------------+

                         Figure 4: SCHC Data Header

4.5.  SCHC Profiles

   A SCHC profile is the specification to adapt the use of SCHC with the
   necessities of the technology to which it is applied.  In the case of
   star topologies and because LPWAN technologies [rfc8376] have strict
   yet distinct constraints, e.g., in terms of maximum frame size,
   throughput, and directionality, also a SCHC end-point and the
   fragmentation model with the parameters' values for its use.

   Appendix D.  "SCHC Parameters" of [rfc8724] lists the information
   that an LPWAN technology-specific document must provide to profile
   SCHC fragmentation for that technology.

   As an example, [rfc9011] provides the SCHC fragmentation profile for
   LoRaWAN networks.

4.6.  SCHC Operation

   The SCHC operation requires a shared sense of which SCHC Device is
   Uplink (Dev to App) and which is Downlink (App to Dev), see
   [rfc8376].  In a star deployment, the hub is always considered Uplink
   and the spokes are Downlink.  The expectation is that the hub and
   spoke derive knowledge of their role from the network configuration
   and SCHC does not need to signal which is hub thus Uplink vs. which
   is spoke thus Downlink.  In other words, the link direction is
   determined from extrinsic properties, and is not advertised in the
   protocol.

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   Nevertheless, SCHC is very generic and its applicability is not
   limited to star-oriented deployments and/or to use cases where
   applications are very static and the state provisioned in advance.
   In particular, a peer-to-peer (P2P) SCHC end-point (see Section 4.4)
   may be set up between peers of equivalent capabilities, and the link
   direction cannot be inferred, either from the network topology nor
   from the device capability.

   In that case, by convention, the device that initiates the connection
   that sustains the SCHC end-point is considered as being Downlink,
   i.e. it plays the role of the Dev in [rfc8724].

   This convention can be reversed, e.g., by configuration, but for
   proper SCHC operation, it is required that the method used ensures
   that both ends are aware of their role, and then again this
   determination is based on extrinsic properties.

4.6.1.  SCHC Rules

   SCHC Rules are a description of the header protocols fields, into a
   list of Field Descriptors.  The [rfc8724] gives the format of the
   Rule description for C/D, F/R and non-compression.  In the same
   manner the SCHC Control Header and SCHc CORECONF_Management will use
   the [rfc8724] field descriptors to compress the format information.

   Each type of Rule is identified with a RuleID.  There are different
   types of Rules: C/D, F/R, SCHC Control Header, CORECONF_Management
   and No Compression.  Notice that each Rule type used an independent
   range of RuleID to identify its rules.

   A Rule does not describe how the compressor parses a datagram header.
   Rules only describe the behavior for each header field.

   SCHC Action.  ToDo

4.6.2.  SoR identification

   ToDo

4.7.  SCHC Management

   RFC9363 writes that only the management can be done by the two
   entities of the end-point, and other SoR cannot be manipulated.

   Management rules are explicitly define in the SoR, see Figure 5.
   They are compression Rules for CORECONF messages to get or modify the
   SoR of the end-point.  The management can be limited with the
   [I-D.ietf-schc-access-control] access definition.

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   +-----------------+                 +-----------------+
   |       ^         |                 |       ^         |
   |  C/D  !  M ___  |                 |       !  M ___  |
   |       +-->[SoR] |       ...       |       +-->[SoR] |
   |       !   [___] |                 |       !   [___] |
   |       !         |                 |       !         |
   |      F/R        |                 |      F/R        |
   +------ins_id1----+-----ins_idi-----+------ins_idn----+
   .                   C/D  !                       ___  .
   .                        +--------------------->[SoR] .
   .                       F/R               M     [___] .
   +.................. Discriminator ....................+

                        Figure 5: Inband Management

4.7.1.  SCHC Instance Manager

   The SCHC Instance Manager provides the management of SCHC end-points,
   the SoR of each end-point and the dialog between hosts to keep the
   SCHC synchronization, and the establishment of SCHC Instances with
   peer nodes.  Changes that involve the SoR must be transactional, in a
   way that ensures that the compression and decompression of a datagram
   is done with the same SoR on every end-points.

   The management of the SCHC end-points includes the capability for the
   end-points to modify the common SoR, by:

   *  modifyng rules values (such as TV, MO or CDA) in existing rules,

   *  adding or

   *  removing rules.

   The rule management uses the CORECONF interface based on CoAP.  The
   management traffic is carried as SCHC compressed datagrams tagged to
   some specific rule IDs.

4.7.2.  SCHC Data Model

   A SCHC end-point, summarized in the Figure 6, implies C/D and/or F/R
   and CORECONF_Management and SCHC end-points Rules present in both end
   and that both ends are provisioned with the same SoR.

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           -----                                  -----
          [ SoR ]                                [ SoR ]
           -----                                  -----
             .                                      .
             .                                      .
             .                                      .
          +- M ---+                              +- M ---+
      <===| R & D |<===                      <===| C & F |<===
      ===>| C & F |===>                      ===>| R & D |===>
          +-------+                              +-------+

                     Figure 6: Summarized SCHC elements

   A common rule representation that expresses the SCHC rules in an
   interoperable fashion is needed to be able to provision end-points
   from different vendors to that effect, [rfc9363] defines a rule
   representation using the YANG [rfc7950] formalism.

   [rfc9363] defines a YANG data model to represent the rules.  This
   enables the use of several protocols for rule management, such as
   NETCONF[RFC6241], RESTCONF[RFC8040], and
   CORECONF[I-D.ietf-core-comi].  NETCONF uses SSH, RESTCONF uses HTTPS,
   and CORECONF uses CoAP(s) as their respective transport layer
   protocols.  The data is represented in XML under NETCONF, in
   JSON[RFC8259] under RESTCONF and in CBOR[RFC8949] under CORECONF.

                  create
           -----  read    +=======+
          [ SoR ]<------->|Rule   |<-----+ NETCONF,
           -----  update  |Manager|      | RESTCONF or
                   delete +=======+      | CORECONF
              +--------------------------+ request
              |
              v M
          +---+---+
      <===| R & D |<===
      ===>| C & F |===>
          +-------+

                     Figure 7: Summerized SCHC elements

   The Rule Manager (RM) is in charge of handling data derived from the
   YANG Data Model and apply changes to the context and SoR of each SCHC
   end-point Figure 7.

   The RM is an Application using the Internet to exchange information,
   therefore:

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   *  for the network-level SCHC, the communication does not require
      routing.  Each of the end-points having an RM and both RMs can be
      viewed on the same link, therefore wellknown Link Local addresses
      can be used to identify the Device and the core RM.  L2 security
      MAY be deemed as sufficient, if it provides the necessary level of
      protection.

   *  for application-level SCHC, routing is involved and global IP
      addresses SHOULD be used.  End-to-end encryption is RECOMMENDED.

   Management messages can also be carried in the negotiation protocol,
   for instace, the [I-D.ietf-schc-over-ppp] proposes a solution.  The
   RM traffic may be itself compressed by SCHC: if CORECONF protocol is
   used, [rfc8824] can be applied.

5.  SCHC Architecture

   As described in [rfc8824], SCHC combining several SCHC end-points.
   The [rfc8724] states that a SCHC end-point needs the rules to process
   C/D and F/R before the SCHC Instance starts and that the SoR of the
   end-point control layer cannot be modified.  However, the rules may
   be updated in certain end-points to improve the performance of C/D,
   F/R, or CORECONF_Management.  The [I-D.ietf-schc-access-control]
   defines the possible modifications and who can modify, update, create
   and delete Rules or part of them in the end-points' SoR.

   As represented in Figure 8, the compression of the IP and UDP headers
   may be operated by a network SCHC end-point whereas the end-to-end
   compression of the application payload happens between the Device and
   the application.  The compression of the application payload may be
   split in two end-points to deal with the encrypted portion of the
   application PDU.  Fragmentation applies before LPWAN transmission
   layer.

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            (Device)            (NGW)                           (App)

            +--------+                                        +--------+
     A S    |  CoAP  |                                        |  CoAP  |
     p C    |  inner |                                        |  inner |
     p H    +--------+                                        +--------+
     . C    |  SCHC  |                                        |  SCHC  |
            |  inner |   cryptographical boundary             |  inner |
    -._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-.._.-._.-._.-._.-._
     A S    |  CoAP  |                                        |  CoAP  |
     p C    |  outer |                                        |  outer |
     p H    +--------+                                        +--------+
     . C    |  SCHC  |                                        |  SCHC  |
            |  outer |   layer / functional boundary          |  outer |
    -._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.--._.-._.-._.-._
     N      .  UDP   .                                        .  UDP   .
     e      ..........     ..................                 ..........
     t      .  IPv6  .     .      IPv6      .                 .  IPv6  .
     w S    ..........     ..................                 ..........
     o C    .SCHC/L3 .     . SCHC/L3.       .                 .        .
     r H    ..........     ..........       .                 .        .
     k C    .  LPWAN .     . LPWAN  .       .                 .        .
            ..........     ..................                 ..........
                ((((LPWAN))))             ------   Internet  ------

           Figure 8: Different SCHC end-points in a global system

   This document defines a generic architecture for SCHC that can be
   used at any of these levels.  The goal of the architectural document
   is to orchestrate the different protocols and data model defined by
   the LPWAN and SCHC working groups to design an operational and
   interoperable framework for allowing IP application over constrained
   networks.

   The Figure 9 shows the protocol stack and the corresponding SCHC
   stratas enabling the compression of the different protocol headers.
   The SCHC Control Header eases the introduction of intermediary host
   in the end-to-end communication transparently.  All the SCHC Control
   Headers are compressed and in some cases are elided, for example for
   LPWAN networks.  The layers using encryption does not have a SCHC
   Control Header in the middle because they are the same entity.
   Figure 10 shows an example of an IP/UDP/CoAP in an LPWAN network.

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   DEV                                 NGW              APP

   {[(Encrypted Application Layer)]} . . . . . . . . {[(EAL)]}
   (Application Layer Protocol) . . . . . . . . . . .({[ALP]})
   (SCHC) . . . . . . . . . . . . . . . . . . . . . ({[SCHC]})
   {[(Encrypted Security Layer)]} . . . . . . . . . .{[(ESL)]}
   {(Security Layer Protocol)}. . . . . . . . . . . . .{(SLP)}
   {(SCHC)} . . . . . . . . . . . . . . . . . . . . . {(SCHC)}
   (Transport Layer Protocol). . . (TLP) TLP . . . . . .TLP
   {(SCHC)} . . . . . . . . . . {(SCHC)}
   (Internet Layer Protocol) . . . (IP)  IP . . . . . . IP
   (SCHC). . . . . . . . . . . . .(SCHC)
   Network Layer Protocol . . . . . . . . . . . . . . . NLP

   Where: {} Optional; [] Encrypted; () Compressed.

                        Figure 9: SCHC Architecture

   In Figure 9, each line represents a layer or a stratum, parentheses
   surround a compressed header, and if it is optional, it has curly
   brackets.  All the SCHC strata are compressed.  Square brackets
   represent the encrypted data; if the encryption is optional, curly
   brackets precede the square brackets.

   Figure 10 represents the stack of SCHC end-points that operate over 3
   strata, one for OSCORE, one for CoAP, and one for IP and UDP.

      +--------------------------OSCORE-------------------------+
      | +-----------------+                 +-----------------+ |
      | |       ^         |                 |       ^         | |
      | |  C/D  !  M ___  |                 |       !  M ___  | |
   S  | |       +-->[SoR] |       ...       |       +-->[SoR] | |
   C  | |       !   [___] |                 |       !   [___] | |
   H  | |       !         |                 |       !         | |
   C  | |      F/R        |                 |      F/R        | |
      | +------ins_id1----+-----ins_idi-----+------ins_idn----+ |
      | |                   C/D  !  (OSCORE)             ___  | |
      | |                        +--------------------->[SoR] | |
      | |                       F/R               M     [___] | |
      +------- Discriminator: IP:A->B/UDP, prot = OSCORE--------+

             IP/UDP,port=CoAP  CoAP  ( ) (OSCORE)
                ^                _____^     ^
                |               /           |
                |      (SCHC Control Header)( SCHC-compressed data)
             |

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      +-------- | ---------------CoAP---------------------------+
      | +-----------------+                 +-----------------+ |
      | |       ^         |                 |       ^         | |
      | |  C/D  !  M ___  |                 |       !  M ___  | |
   S  | |       +-->[SoR] |       ...       |       +-->[SoR] | |
   C  | |       !   [___] |                 |       !   [___] | |
   H  | |       !         |                 |       !         | |
   C  | |      F/R        |                 |      F/R        | |
      | +------ins_id1----+-----ins_idi-----+------ins_idn----+ |
      | |                   C/D  !  (CoAP)               ___  | |
      | |                        +--------------------->[SoR] | |
      | |                       F/R               M     [___] | |
      +------- Discriminator: IP:A->B/UDP port=SCHC  -----------+

             IP/UDP   ( ) (CoAP)   PAYLOAD2
                ^      ^     ^_____________
                |      |                   \
                |      +-(SCHC Control Header)( SCHC-compressed data)
             |
      +-------- | --------------IP/UDP--------------------------+
      | +------ | --------+                 +-----------------+ |
      | |       |         |                 |       ^         | |
      | |  C/D  !  M ___  |                 |       !  M ___  | |
   S  | |       +-->[SoR] |       ...       |       +-->[SoR] | |
   C  | |       !   [___] |                 |       !   [___] | |
   H  | |       !         |                 |       !         | |
   C  | |      F/R        |                 |      F/R        | |
      | +------ins_id1----+-----ins_idi-----+------ins_idn----+ |
      | |                   C/D  !  (IP/UDP)                  | |
      | |                        +--------------------->[SoR] | |
      | |                       F/R               M     [___] | |
      +-+-----------Discriminator: interface ID        -------+-+
   N      ______________^
   E     /
   T    |    ( ) (IP/UDP)    PAYLOAD1
   W    |     ^    ^_______
        |     |            \
        +-(SCHC Control Header)( SCHC-compressed data)

                       Figure 10: SCHC Strata Example

6.  The Static Context Header Compression

   SCHC [rfc8724] specifies an extreme compression capability based on a
   description that must match on the compressor and decompressor side.
   This description comprises a set of Compression/Decompression (C/D)
   rules.

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   The SCHC Parser analyzes incoming datagrams and creates a list of
   fields that it matches against the compression rules.  The rule that
   matches is used to compress the datagram, and the rule identifier
   (RuleID) is transmitted together with the compression residue to the
   decompressor.  Based on the RuleID and the residue, the decompressor
   can rebuild the original datagram and forward it in its uncompressed
   form over the Internet.  When no Rule matches the header, the No
   Compression Rule is used.  When several Rules match the header the
   implementation must choose one.  How it is done or based on which
   parameters is out of the scope of this document.  SCHC compresses
   datagrams and there is no notion of flows.

   [rfc8724] also provides a Fragmentation/Reassembly (F/R) capability
   to cope with the maximum and/or variable frame size of a Link, which
   is extremely constrained in the case of an LPWAN network.

   If a SCHC-compressed datagram is too large to be sent in a single
   Link-Layer PDU, the SCHC fragmentation can be applied on the
   compressed datagram.  The process of SCHC fragmentation is similar to
   that of compression; the fragmentation rules that are programmed for
   this Device are checked to find the most appropriate one, regarding
   the SCHC datagram size, the link error rate, and the reliability
   level required by the application.

   The ruleID allows to determine if it is a compression or
   fragmentation rule or any other type of Rule.

6.1.  SCHC over Network Technologies

   SCHC can be used in multiple environments and multiple protocols.  It
   was designed by default to work on native MAC frames with LPWAN
   technologies such as LoRaWAN[rfc9011], IEEE std 802.15.4
   [I-D.ietf-6lo-schc-15dot4], and SigFox[rfc9442].

   To operate SCHC over Ethernet, IPv6, and UDP, the definition of,
   respectively, an Ethertype, an IP Protocol Number, and a UDP Port
   Number are necessary, more in
   [I-D.ietf-intarea-schc-protocol-numbers].  In either case, there's a
   need for a SCHC Control Header that is sufficient to identify the
   SCHC peers (endpoints) and their role (device vs. app), as well as
   the SCHC Instance between those peers that the datagram pertains to.

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   In either of the above cases, the expectation is that the SCHC
   Control Header is transferred in a compressed form.  This implies
   that the rules to uncompress the header are well known and separate
   from the rules that are used to uncompress the SCHC Data Header.  The
   expectation is that for each stratum, the format of the SCHC Control
   Header and the compression rules are well known, with enough
   information to identify the SCHC Instance at that stratum, but there
   is no expectation that they are the same across strata.

6.1.1.  SCHC over PPP

   The LPWAN architecture (Figure 15) generalizes the model to any kind
   of peers.  In the case of more capable devices, a SCHC Device may
   maintain more than one end-point with the same peer, or a set of
   different peers.  Since SCHC does not signal the end-point in its
   datagrams, the information must be derived from a lower layer point
   to point information.  For end-point, the SCHC end-point control can
   be associated one-to-one with a tunnel, a TLS SCHC Instance, or a TCP
   or a PPP connection.

   For end-point, [I-D.ietf-schc-over-ppp] describes a type of
   deployment where the C/D and/or F/R operations are performed between
   peers of equal capabilities over a PPP [rfc2516] connection.  SCHC
   over PPP illustrates that with SCHC, the protocols that are
   compressed can be discovered dynamically and the rules can be fetched
   on-demand using CORECONF messages Rules, ensuring that the peers use
   the exact same set of rules.

       +----------+  Wi-Fi /   +----------+                ....
       |    IP    |  Ethernet  |    IP    |            ..          )
       |   Host   +-----/------+  Router  +----------(   Internet   )
       | SCHC C/D |  Serial    | SCHC C/D |            (         )
       +----------+            +----------+               ...
                   <-- SCHC -->
                     over PPP

                    Figure 11: PPP-based SCHC Deployment

   In that case, the SCHC end-point is derived from the PPP connection.
   This means that there can be only one end-point per PPP connection,
   and that all the flow and only the flow of that end-point is
   exchanged within the PPP connection.  As discussed in Section 7, the
   Uplink direction is from the node that initiated the PPP connection
   to the node that accepted it.

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6.1.2.  SCHC over Ethernet

   Before the SCHC compression takes place, the SCHC Control Header
   showed in the Figure 12, is virtually inserted before the real
   protocol header and data that are compressed in the SCHC Instance,
   e.g. a IPv6 in this figure.

                                           <--- SCHC datagram ->
    +------------------+------------------+---------+-----------+
    |                  | SCHC             | SCHC    |  uncomp-  |
    | IEEE 802 Header  | Stratum Header   | Data    |  pressed  |
    | Ethertype = SCHC | Ethertype = IPv6 | Header  |  payload  |
    +------------------+------------------+---------+-----------+
                        <-
                          SCHC overhead
                                        ->

                       Figure 12: SCHC over Ethernet

6.1.3.  SCHC over IPv6

   In the case of IPv6, the expectation is that the Upper Layer Protocol
   (ULP) checksum can be elided in the SCHC compression of the ULP,
   because the SCHC Control Header may have its own checksum that
   protects both the SCHC Control Header and the whole ULP, header and
   payload.

   The SCHC Control Header between IPv6 and the ULP is not needed
   because of the Next Header field on the IPv6 header format.

                                    <--- SCHC datagram ->
    +-------------+----------------+---------+-----------+
    |             | SCHC           | SCHC    |  uncomp-  |
    | IPv6 Header | Stratum Header | Data    |  pressed  |
    |  NH=SCHC    | NH = ULP       | Header  |  payload  |
    +-------------+----------------+---------+-----------+
                   <-
                   SCHC overhead
                                 ->

                         Figure 13: SCHC over IPv6

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   In the air, both the SCHC Control Header and the ULP are compressed.
   The SCHC Instance endpoints are typically identified by the source
   and destination IP addresses.  If the roles are well-known, then the
   endpoint information can be elided and deduced from the IP header.
   If there is only one SCHC Instance, it can be elided as well,
   otherwise a rule and residue are needed to extract the SCHC Instance
   ID.

6.1.4.  SCHC over UDP

   When SCHC operates over the Internet, middleboxes may block datagrams
   with a next header that is SCHC.  To avoid that issue, it would be
   desirable to prepend a UDP header before the SCHC Control Header as
   shown in figure Figure 14.

                                                  <--- SCHC datagram ->
    +-------------+-------------+----------------+---------+-----------+
    |             |             | SCHC           | SCHC    |  uncomp-  |
    | IPv6 Header | UDP Header  | Stratum Header | Data    |  pressed  |
    |  NH=UDP     | Port = SCHC | NH = ULP       | Header  |  payload  |
    +-------------+-------------+----------------+---------+-----------+
                   <-
                          SCHC overhead
                                               ->
   ~

                          Figure 14: SCHC over UDP

   In that case, the destination port can indicate SCHC as in an header
   chain, and the source port can indicate the SCHC Instance in which
   case it can be elided in the compressed form of the SCHC Control
   Header.  The UDP checksum protects both the SCHC Control Header and
   the whole ULP, so the SCHC and the ULP checksums can both be elided.
   In other words, in the SCHC over UDP case, the SCHC Control Header
   can be fully elided, but the datagram must carry the overhead of a
   full UDP header.

7.  SCHC Endpoints for LPWAN Networks

   Section 3 of [rfc8724] depicts a typical network architecture for an
   LPWAN network, simplified from that shown in [rfc8376] and reproduced
   in Figure 15.

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    ()   ()   ()       |
     ()  () () ()     / \       +---------+
   () () () () () () /   \======|    ^    |             +-----------+
    ()  ()   ()     |           | <--|--> |             |Application|
   ()  ()  ()  ()  / \==========|    v    |=============|   Server  |
     ()  ()  ()   /   \         +---------+             +-----------+
    Dev            RGWs             NGW                      App

               Figure 15: Typical LPWAN Network Architecture

   Typically, an LPWAN network topology is star-oriented, which means
   that all datagrams between the same source-destination pair follow
   the same path from/to a central point.  In that model, highly
   constrained Devices (Dev) exchange information with LPWAN Application
   Servers (App) through a central Network Gateway (NGW), which can be
   powered and is typically a lot less constrained than the Devices.
   Because Devices embed built-in applications, the traffic flows to be
   compressed are known in advance and the location of the C/D and F/R
   functions (e.g., at the Dev and NGW), and the associated rules, can
   be pre provisioned in the system before use.

7.1.  SCHC Device Lifecycle

   In the context of LPWANs, the expectation is that SCHC rules are
   associated with a physical device that is deployed in a network.
   This section describes the actions taken to enable an automatic
   commissioning of the device in the network.

7.1.1.  Device Development

   The expectation for the development cycle is that message formats are
   documented as a data model that is used to generate rules.  Several
   models are possible:

   1.  In the application model, an interface definition language and
       binary communication protocol such as Apache Thrift is used, and
       the parser code includes the SCHC operation.  This model imposes
       that both ends are compiled with the generated structures and
       linked with generated code that represents the rule operation.

   2.  In the device model, the rules are generated separately.  Only
       the device-side code is linked with generated code.  The Rules
       are published separately to be used by a generic SCHC engine that
       operates in a middle box such as a SCHC gateway.

   3.  In the protocol model, both endpoint generate a datagram format
       that is imposed by a protocol.  In that case, the protocol itself
       is the source to generate the Rules.  Both ends of the SCHC

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       compression are operated in middle boxes, and special attention
       must be taken to ensure that they operate on the compatible SoR,
       basically the same major version of the same SoR.

   Depending on the deployment, the tools that generate the Rules should
   provide knobs to optimize the SoR, e.g., more rules vs. larger
   residue.

7.1.2.  Rules Publication

   In the device model and in the protocol model, at least one of the
   endpoints must obtain the SoR dynamically.  The expectation is that
   the SoR are published to a reachable repository and versionned
   (minor, major).  Each SoR should have its own Uniform Resource Names
   (URN) [RFC8141] and a version.

   The SoR should be authenticated to ensure that it is genuine, or
   obtained from a trusted app store.  A corrupted SoR may be used for
   multiple forms of attacks, more in Section 8.

7.1.3.  SCHC Device Deployment

   The device and the network should mutually authenticate themselves.
   The autonomic approach [RFC8993] provides a model to achieve this at
   scale with zero touch, in networks where enough bandwidth and compute
   are available.  In highly constrained networks, one touch is usually
   necessary to program keys in the devices.

   The initial handshake between the SCHC endpoints should comprise a
   capability exchange whereby URN and the version of the SoR are
   obtained or compared.  SCHC may not be used if both ends can not
   agree on an URN and a major version.
   Manufacturer Usage Descriptions (MUD) [RFC8520] may be used for that
   purpose in the device model.

   Upon the handshake, both ends can agree on a SoR, their role when the
   rules are asymmetrical, and fetch the SoR if necessary.  Optionally,
   a node that fetched a SoR may inform the other end that it is reacy
   from transmission.

7.1.4.  SCHC Device Maintenance

   URN update without device update (bug fix) FUOTA => new URN =>
   reprovisioning

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7.1.5.  SCHC Device Decommissionning

   Signal from device/vendor/network admin

8.  Security Considerations

   SCHC is sensitive to the rules that could be abused to form arbitrary
   long messages or as a form of attack against the C/D and/or F/R
   functions, say to generate a buffer overflow and either modify the
   Device or crash it.  It is thus critical to ensure that the rules are
   distributed in a fashion that is protected against tempering, e.g.,
   encrypted and signed.

9.  IANA Consideration

   This document has no request to IANA

10.  Acknowledgements

   The authors would like to thank (in alphabetic order): Laurent
   Toutain

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/rfc/rfc2119>.

   [RFC8141]  Saint-Andre, P. and J. Klensin, "Uniform Resource Names
              (URNs)", RFC 8141, DOI 10.17487/RFC8141, April 2017,
              <https://www.rfc-editor.org/rfc/rfc8141>.

   [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>.

   [rfc8724]  Minaburo, A., Toutain, L., Gomez, C., Barthel, D., and JC.
              Zuniga, "SCHC: Generic Framework for Static Context Header
              Compression and Fragmentation", RFC 8724,
              DOI 10.17487/RFC8724, April 2020,
              <https://www.rfc-editor.org/rfc/rfc8724>.

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   [rfc8824]  Minaburo, A., Toutain, L., and R. Andreasen, "Static
              Context Header Compression (SCHC) for the Constrained
              Application Protocol (CoAP)", RFC 8824,
              DOI 10.17487/RFC8824, June 2021,
              <https://www.rfc-editor.org/rfc/rfc8824>.

11.2.  Informative References

   [I-D.ietf-6lo-schc-15dot4]
              Gomez, C. and A. Minaburo, "Transmission of SCHC-
              compressed packets over IEEE 802.15.4 networks", Work in
              Progress, Internet-Draft, draft-ietf-6lo-schc-15dot4-11,
              14 October 2025, <https://datatracker.ietf.org/doc/html/
              draft-ietf-6lo-schc-15dot4-11>.

   [I-D.ietf-core-comi]
              Veillette, M., Van der Stok, P., Pelov, A., Bierman, A.,
              and C. Bormann, "CoAP Management Interface (CORECONF)",
              Work in Progress, Internet-Draft, draft-ietf-core-comi-20,
              6 May 2025, <https://datatracker.ietf.org/doc/html/draft-
              ietf-core-comi-20>.

   [I-D.ietf-intarea-schc-protocol-numbers]
              Moskowitz, R., Card, S. W., Wiethuechter, A., and P.
              Thubert, "Protocol Numbers for SCHC", Work in Progress,
              Internet-Draft, draft-ietf-intarea-schc-protocol-numbers-
              02, 8 April 2024, <https://datatracker.ietf.org/doc/html/
              draft-ietf-intarea-schc-protocol-numbers-02>.

   [I-D.ietf-schc-access-control]
              Minaburo, A., Toutain, L., and I. Martinez, "SCHC Access
              Control", Work in Progress, Internet-Draft, draft-ietf-
              schc-access-control-00, 13 December 2023,
              <https://datatracker.ietf.org/doc/html/draft-ietf-schc-
              access-control-00>.

   [I-D.ietf-schc-over-ppp]
              Thubert, P., "SCHC over PPP", Work in Progress, Internet-
              Draft, draft-ietf-schc-over-ppp-00, 25 July 2023,
              <https://datatracker.ietf.org/doc/html/draft-ietf-schc-
              over-ppp-00>.

   [rfc2516]  Mamakos, L., Lidl, K., Evarts, J., Carrel, D., Simone, D.,
              and R. Wheeler, "A Method for Transmitting PPP Over
              Ethernet (PPPoE)", RFC 2516, DOI 10.17487/RFC2516,
              February 1999, <https://www.rfc-editor.org/rfc/rfc2516>.

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Internet-Draft              SCHC Architecture               October 2025

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <https://www.rfc-editor.org/rfc/rfc6241>.

   [rfc7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/rfc/rfc7950>.

   [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
              <https://www.rfc-editor.org/rfc/rfc8040>.

   [RFC8259]  Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
              Interchange Format", STD 90, RFC 8259,
              DOI 10.17487/RFC8259, December 2017,
              <https://www.rfc-editor.org/rfc/rfc8259>.

   [rfc8376]  Farrell, S., Ed., "Low-Power Wide Area Network (LPWAN)
              Overview", RFC 8376, DOI 10.17487/RFC8376, May 2018,
              <https://www.rfc-editor.org/rfc/rfc8376>.

   [RFC8520]  Lear, E., Droms, R., and D. Romascanu, "Manufacturer Usage
              Description Specification", RFC 8520,
              DOI 10.17487/RFC8520, March 2019,
              <https://www.rfc-editor.org/rfc/rfc8520>.

   [RFC8949]  Bormann, C. and P. Hoffman, "Concise Binary Object
              Representation (CBOR)", STD 94, RFC 8949,
              DOI 10.17487/RFC8949, December 2020,
              <https://www.rfc-editor.org/rfc/rfc8949>.

   [RFC8993]  Behringer, M., Ed., Carpenter, B., Eckert, T., Ciavaglia,
              L., and J. Nobre, "A Reference Model for Autonomic
              Networking", RFC 8993, DOI 10.17487/RFC8993, May 2021,
              <https://www.rfc-editor.org/rfc/rfc8993>.

   [rfc9011]  Gimenez, O., Ed. and I. Petrov, Ed., "Static Context
              Header Compression and Fragmentation (SCHC) over LoRaWAN",
              RFC 9011, DOI 10.17487/RFC9011, April 2021,
              <https://www.rfc-editor.org/rfc/rfc9011>.

   [rfc9363]  Minaburo, A. and L. Toutain, "A YANG Data Model for Static
              Context Header Compression (SCHC)", RFC 9363,
              DOI 10.17487/RFC9363, March 2023,
              <https://www.rfc-editor.org/rfc/rfc9363>.

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   [rfc9442]  Zúñiga, J., Gomez, C., Aguilar, S., Toutain, L., Céspedes,
              S., Wistuba, D., and J. Boite, "Static Context Header
              Compression (SCHC) over Sigfox Low-Power Wide Area Network
              (LPWAN)", RFC 9442, DOI 10.17487/RFC9442, July 2023,
              <https://www.rfc-editor.org/rfc/rfc9442>.

Authors' Addresses

   Alexander Pelov
   IMT Atlantique
   rue de la Chataigneraie
   35576 Cesson-Sevigne Cedex
   France
   Email: alexander.pelov@imt-atlantique.fr

   Pascal Thubert
   06330 Roquefort les Pins
   France
   Email: pascal.thubert@gmail.com

   Ana Minaburo
   Consultant
   35510 Cesson-Sevigne Cedex
   France
   Email: anaminaburo@gmail.com

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