Static Context Header Compression (schc) Internet Drafts


      
 Static Context Header Compression (SCHC) for the Constrained Application Protocol (CoAP)
 
 draft-ietf-schc-8824-update-03.txt
 Date: 21/10/2024
 Authors: Marco Tiloca, Laurent Toutain, Ivan Martinez, Ana Minaburo
 Working Group: Static Context Header Compression (schc)
This document defines how to compress Constrained Application Protocol (CoAP) headers using the Static Context Header Compression and fragmentation (SCHC) framework. SCHC defines a header compression mechanism adapted for constrained devices. SCHC uses a static description of the header to reduce the header's redundancy and size. While RFC 8724 describes the SCHC compression and fragmentation framework, and its application for IPv6/UDP headers, this document applies SCHC to CoAP headers. The CoAP header structure differs from IPv6 and UDP, since CoAP uses a flexible header with a variable number of options, themselves of variable length. The CoAP message format is asymmetric: the request messages have a header format different from the format in the response messages. This specification gives guidance on applying SCHC to flexible headers and how to leverage the asymmetry for more efficient compression Rules. This document replaces and obsoletes RFC 8824.
 Protocol Numbers for SCHC
 
 draft-ietf-schc-protocol-numbers-00.txt
 Date: 25/06/2024
 Authors: Robert Moskowitz, Stuart Card, Adam Wiethuechter, Pascal Thubert
 Working Group: Static Context Header Compression (schc)
This document requests an Internet Protocol Number, an Ethertype, and UDP port assignment for SCHC. The Internet Protocol Number request is so that SCHC can be used for IP independent SCHC of other transports such as UDP and ESP. The Ethertype is to support generic use of native SCHC over any IEEE 802 technology for IP and non-IP protocols. The UDP port request is to support End-to-End SCHC through potentially blocking firewalls.
 Static Context Header Compression and Fragmentation over networks prone to disruptions
 
 draft-ietf-schc-over-networks-prone-to-disruptions-00.txt
 Date: 26/08/2024
 Authors: Edgar Ramos, Lorenzo Corneo, Ana Minaburo
 Working Group: Static Context Header Compression (schc)
This document describes the use of SCHC over different network topologies and devices regardless of their capabilities and configurations. The use of SCHC will bring connectivity to devices with disruptive connections caused by restrained use of battery and connectionless setups with long delays and latency.
 Static Context Header Compression (SCHC) for the Internet Control Message Protocol (ICMPv6)
 
 draft-ietf-schc-icmpv6-compression-01.txt
 Date: 25/11/2024
 Authors: Dominique Barthel, Laurent Toutain
 Working Group: Static Context Header Compression (schc)
This document describes how the ICMPv6 protocol can be integrated into the SCHC architecture. It extends the YANG Data Model with new field IDs specific to ICMPv6 headers. To enhance the compression of ICMPv6 error messages, the document also introduces two new Matching Operators and two new Compression Decompression Actions to manipulate the ICMPv6 payload. Finally, for constrained networks such as LPWAN, it introduces a proxy behavior, where a SCHC Core end-point may anticipate the device reaction to incorrect messages.


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Static Context Header Compression (schc)

WG Name Static Context Header Compression
Acronym schc
Area Internet Area (int)
State Active
Charter charter-ietf-schc-01 Approved
Document dependencies
Personnel Chairs Alexander Pelov, Pascal Thubert
Area Director Éric Vyncke
Delegates Éric Vyncke, Laurent Toutain
Mailing list Address schc@ietf.org
To subscribe https://www.ietf.org/mailman/listinfo/schc
Archive https://mailarchive.ietf.org/arch/browse/schc/
Chat Room address https://zulip.ietf.org/#narrow/stream/schc

Charter for Working Group

The scope of the Static Context Header Compression (SCHC) Working Group (to be pronounced as "chic" in French) is to extend the benefits of the RFC 8724 SCHC technology in Low-Power Wide-Area (LPWA) and non-LPWA networks, including Low Power devices such as zero-energy / scavenging devices that may operate in Delay Tolerant mode. To that effect, the group will provide specifications for the application of SCHC over underlying layers, where underlying layers include but are not limited to UDP tunnels, IP, PPP, and Ethernet, as well as the use of SCHC by upper-layer protocols.

To extend SCHC over multi-hop networks with remote endpoints, there is a need in the data plane to signal the SCHC session and some operational values in the packets. For instance, the INT-AREA WG is working on a SCHC protocol type for IP and a SCHC Ethertype (in coordination with IEEE) for Ethernet. The WG will provide standards track specifications for a SCHC Header that conveys the SCHC Session Info over IP.

A complete SCHC solution also requires control plane technologies to secure the operations and manage the SCHC sessions, devices, and gateways. The group will provide specifications to securely identify the rule sets and negotiate the associated parameters between the pair of endpoints. The group will also work on the rules provisioning to the nodes, including the instantiation of generic rules to the nodes and networks in which they are applied.

The WG will work on:

1) Perform SCHC Maintenance, including enabling SCHC mechanisms for Upper layer Protocols, and providing additional reliability mechanisms such as FEC for fragments.

2) Produce a Standards Track document to enable Operations, Administration, and Maintenance (OAM), including support for delayed (as some devices can be asleep) or proxied (via the gateway) reachability verification.

3) Produce Standard Track documents for SCHC over underlying layers and carried protocols over SCHC where underlying layers includes but is not limited to IP, UDP tunnels, PPP, and Ethernet and carried protocols may include IPv4, ICMPv6-based protocols, TCP, IP tunnels, DLMS, and other protocols over CoAP such as LwM2M; define and maintain data models for the protocols supported by SCHC.

4) Produce an informational document describing how a carried protocol can use SCHC.

5) Define in a Standard Track document the SCHC Protocol Header to convey SCHC Session Info over IP

6) Produce Standard Track documents for SCHC Rule Discovery and Parameter Negotiation, including the specification of how work from the IETF security area is leveraged to secure these operations

7) Produce Standard Track documents for SCHC Rule Provisioning, including the specification of generic SCHC rules that can be instantiated, e.g., to apply to a certain node or within a certain network.

The SCHC WG will coordinate with INTAREA WG for the IP protocol type definition, 6MAN WG for possible ICMPv6 code(s), and with other WGs for possible Protocols-over-SCHC or SCHC-over-protocol activities (e.g., in TSV area). It will work with the relevant security area WGs to appropriately secure the SCHC session. If required, the SCHC WG will liaise and coordinate with other Standard Development Organisations when SCHC will be used over or under protocols not defined with IETF.

Milestones

Date Milestone Associated documents
Mar 2025 Request for publication of a standard track specification for rules provisioning
Mar 2025 Request for publication of a standard track specification of a standard track specification SCHC over IP
Mar 2025 Request for publication of a standard track specification for rules discovery and parameters negotiation
Feb 2025 Request for publication of a standard track specification for generic SCHC header
Dec 2024 Request for publication of a standard track specification of Operations, Administration, and Maintenance (OAM)
Dec 2024 Request for publication of a standard track specification of FEC for fragments
Mar 2024 Request for publication of an information document about SCHC architecture
Mar 2024 Request for publication of a standard track specification for SCHC over PPP
Dec 2023 WG adoption of a standard track specification of FEC for fragments
Dec 2023 WG adoption of a standard track specification for rules discovery and parameters negotiation
Dec 2023 WG adoption of a standard track specification for rules provisioning
Nov 2023 WG adoption of a standard track specification for generic SCHC header
Nov 2023 WG adoption of a standard track specification SCHC over IP draft-moskowitz-intarea-schc-ip-protocol-number

Done milestones

Date Milestone Associated documents
Done WG adoption of a standard track specification of Operations, Administration, and Maintenance (OAM) draft-barthel-lpwan-oam-schc
Done WG adoption of an information document about SCHC architecture draft-ietf-lpwan-architecture
Done WG adoption of a standard track specification for SCHC over PPP draft-thubert-intarea-schc-over-ppp