CoAP (Constrained Application Protocol) over TCP, TLS, and WebSockets
draft-ietf-core-coap-tcp-tls-03

The information below is for an old version of the document
Document Type Active Internet-Draft (core WG)
Last updated 2016-07-08
Replaces draft-tschofenig-core-coap-tcp-tls, draft-bormann-core-block-bert, draft-bormann-core-coap-sig, draft-savolainen-core-coap-websockets
Stream IETF
Intended RFC status Proposed Standard
Formats plain text pdf html bibtex
Stream WG state WG Document (wg milestone: Oct 2016 - CoAP over TCP, TLS, ... )
Document shepherd Jaime Jimenez
IESG IESG state AD is watching
Consensus Boilerplate Unknown
Telechat date
Responsible AD Alexey Melnikov
Send notices to "Jaime Jimenez" <jaime.jimenez@ericsson.com>
CORE                                                          C. Bormann
Internet-Draft                                   Universitaet Bremen TZI
Intended status: Standards Track                                S. Lemay
Expires: January 9, 2017                              Zebra Technologies
                                                           H. Tschofenig
                                                                ARM Ltd.
                                                               K. Hartke
                                                 Universitaet Bremen TZI
                                                           B. Silverajan
                                        Tampere University of Technology
                                                          B. Raymor, Ed.
                                                               Microsoft
                                                           July 08, 2016

 CoAP (Constrained Application Protocol) over TCP, TLS, and WebSockets
                    draft-ietf-core-coap-tcp-tls-03

Abstract

   The Constrained Application Protocol (CoAP), although inspired by
   HTTP, was designed to use UDP instead of TCP.  The message layer of
   the CoAP over UDP protocol includes support for reliable delivery,
   simple congestion control, and flow control.

   Some environments benefit from the availability of CoAP carried over
   reliable transports such as TCP or TLS.  This document outlines the
   changes required to use CoAP over TCP, TLS, and WebSockets
   transports.

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 http://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 January 9, 2017.

Bormann, et al.          Expires January 9, 2017                [Page 1]
Internet-Draft   TCP/TLS/WebSockets Transports for CoAP        July 2016

Copyright Notice

   Copyright (c) 2016 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
   (http://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 and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   4
   2.  CoAP over TCP . . . . . . . . . . . . . . . . . . . . . . . .   5
     2.1.  Messaging Model . . . . . . . . . . . . . . . . . . . . .   5
     2.2.  UDP-to-TCP gateways . . . . . . . . . . . . . . . . . . .   6
     2.3.  Message Format  . . . . . . . . . . . . . . . . . . . . .   6
     2.4.  Message Transmission  . . . . . . . . . . . . . . . . . .   9
   3.  CoAP over WebSockets  . . . . . . . . . . . . . . . . . . . .  10
     3.1.  Opening Handshake . . . . . . . . . . . . . . . . . . . .  12
     3.2.  Message Format  . . . . . . . . . . . . . . . . . . . . .  12
     3.3.  Message Transmission  . . . . . . . . . . . . . . . . . .  13
     3.4.  Connection Health . . . . . . . . . . . . . . . . . . . .  14
     3.5.  Closing the Connection  . . . . . . . . . . . . . . . . .  14
   4.  Signaling . . . . . . . . . . . . . . . . . . . . . . . . . .  14
     4.1.  Signaling Codes . . . . . . . . . . . . . . . . . . . . .  15
     4.2.  Signaling Option Numbers  . . . . . . . . . . . . . . . .  15
     4.3.  Capability and Settings Messages (CSM)  . . . . . . . . .  15
     4.4.  Ping and Pong Messages  . . . . . . . . . . . . . . . . .  17
     4.5.  Release Messages  . . . . . . . . . . . . . . . . . . . .  18
     4.6.  Abort Messages  . . . . . . . . . . . . . . . . . . . . .  19
     4.7.  Capability and Settings examples  . . . . . . . . . . . .  20
   5.  Block-wise Transfer and Reliable Transports . . . . . . . . .  21
     5.1.  Example: GET with BERT Blocks . . . . . . . . . . . . . .  22
     5.2.  Example: PUT with BERT Blocks . . . . . . . . . . . . . .  22
   6.  CoAP URIs . . . . . . . . . . . . . . . . . . . . . . . . . .  23
     6.1.  CoAP over TCP and TLS URIs  . . . . . . . . . . . . . . .  23
Show full document text