LPWAN Static Context Header Compression (SCHC) for CoAP
draft-ietf-lpwan-coap-static-context-hc-17
| The information below is for an old version of the document | |||
|---|---|---|---|
| Document | Type | Active Internet-Draft (lpwan WG) | |
| Authors | Ana Minaburo , Laurent Toutain , Ricardo Andreasen | ||
| Last updated | 2021-01-21 | ||
| Replaces | draft-toutain-lpwan-coap-static-context-hc | ||
| Stream | Internet Engineering Task Force (IETF) | ||
| Formats | pdf htmlized (tools) htmlized bibtex | ||
| Reviews | |||
| Stream | WG state | Submitted to IESG for Publication | |
| Document shepherd | Pascal Thubert | ||
| Shepherd write-up | Show (last changed 2019-10-09) | ||
| IESG | IESG state | IESG Evaluation::AD Followup | |
| Consensus Boilerplate | Yes | ||
| Telechat date |
Has enough positions to pass. |
||
| Responsible AD | Éric Vyncke | ||
| Send notices to | Pascal Thubert <pthubert@cisco.com> | ||
| IANA | IANA review state | Version Changed - Review Needed | |
lpwan Working Group A. Minaburo
Internet-Draft Acklio
Intended status: Standards Track L. Toutain
Expires: July 25, 2021 Institut MINES TELECOM; IMT Atlantique
R. Andreasen
Universidad de Buenos Aires
January 21, 2021
LPWAN Static Context Header Compression (SCHC) for CoAP
draft-ietf-lpwan-coap-static-context-hc-17
Abstract
This draft defines how to compress the Constrained Application
Protocol (CoAP) using the Static Context Header Compression (SCHC).
SCHC is 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 for 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 protocol messages format is asymmetric:
the request messages have a header format different from the one 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.
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/.
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 July 25, 2021.
Minaburo, et al. Expires July 25, 2021 [Page 1]
Internet-Draft LPWAN CoAP compression January 2021
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document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
2. SCHC Applicability to CoAP . . . . . . . . . . . . . . . . . 4
3. CoAP Headers compressed with SCHC . . . . . . . . . . . . . . 7
3.1. Differences between CoAP and UDP/IP Compression . . . . . 8
4. Compression of CoAP header fields . . . . . . . . . . . . . . 9
4.1. CoAP version field . . . . . . . . . . . . . . . . . . . 9
4.2. CoAP type field . . . . . . . . . . . . . . . . . . . . . 9
4.3. CoAP code field . . . . . . . . . . . . . . . . . . . . . 9
4.4. CoAP Message ID field . . . . . . . . . . . . . . . . . . 10
4.5. CoAP Token fields . . . . . . . . . . . . . . . . . . . . 10
5. CoAP options . . . . . . . . . . . . . . . . . . . . . . . . 10
5.1. CoAP Content and Accept options. . . . . . . . . . . . . 11
5.2. CoAP option Max-Age, Uri-Host, and Uri-Port fields . . . 11
5.3. CoAP option Uri-Path and Uri-Query fields . . . . . . . . 11
5.3.1. Variable-length Uri-Path and Uri-Query . . . . . . . 12
5.3.2. Variable number of Path or Query elements . . . . . . 13
5.4. CoAP option Size1, Size2, Proxy-URI and Proxy-Scheme
fields . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.5. CoAP option ETag, If-Match, If-None-Match, Location-Path,
and Location-Query fields . . . . . . . . . . . . . . . . 13
6. SCHC compression of CoAP extension RFCs . . . . . . . . . . . 13
6.1. Block . . . . . . . . . . . . . . . . . . . . . . . . . . 13
6.2. Observe . . . . . . . . . . . . . . . . . . . . . . . . . 13
6.3. No-Response . . . . . . . . . . . . . . . . . . . . . . . 14
6.4. OSCORE . . . . . . . . . . . . . . . . . . . . . . . . . 14
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