CoAP over WebSockets
draft-savolainen-core-coap-websockets-00

CoRE Working Group                                         T. Savolainen
Internet-Draft                                                 K. Hartke
Intended status: Standards Track                                   Nokia
Expires: January 13, 2014                                  B. Silverajan
                                        Tampere University of Technology
                                                           July 12, 2013

                          CoAP over WebSockets
                draft-savolainen-core-coap-websockets-00

Abstract

   This document specifies how to retrieve and update CoAP resources
   using CoAP requests and responses over the WebSocket Protocol.

Status of this Memo

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   This Internet-Draft will expire on January 13, 2014.

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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
     1.1.  Overview . . . . . . . . . . . . . . . . . . . . . . . . .  4
     1.2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . .  6
   2.  CoAP over WebSockets . . . . . . . . . . . . . . . . . . . . .  6
     2.1.  Opening Handshake  . . . . . . . . . . . . . . . . . . . .  6
     2.2.  Message Format . . . . . . . . . . . . . . . . . . . . . .  7
     2.3.  Message Transmission . . . . . . . . . . . . . . . . . . .  8
     2.4.  Connection Health  . . . . . . . . . . . . . . . . . . . .  8
     2.5.  Closing the Connection . . . . . . . . . . . . . . . . . .  8
   3.  CoAP over WebSockets URIs  . . . . . . . . . . . . . . . . . .  8
   4.  Security Considerations  . . . . . . . . . . . . . . . . . . .  9
   5.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . .  9
     5.1.  URI Scheme Registrations . . . . . . . . . . . . . . . . .  9
     5.2.  WebSocket Subprotocol Registration . . . . . . . . . . . . 11
   6.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 12
   7.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 12
     7.1.  Normative References . . . . . . . . . . . . . . . . . . . 12
     7.2.  Informative References . . . . . . . . . . . . . . . . . . 12
   Appendix A.  Examples  . . . . . . . . . . . . . . . . . . . . . . 13
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16

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1.  Introduction

   The Constrained Application Protocol (CoAP) [I-D.ietf-core-coap] is a
   web protocol designed for communications between resource constrained
   nodes.  By default, CoAP operates on top of UDP or DTLS, but there is
   interest in using CoAP also over other types of transports, such as
   SMS [I-D.becker-core-coap-sms-gprs].

   An interesting transport for CoAP could be the WebSocket Protocol
   [RFC6455].  The WebSocket protocol provides two-way communication
   between a client and a server after upgrading an HTTP [RFC2616]
   connection, and may be available in an environment that does not
   allow transportation of CoAP over UDP.  This environment can be, for
   example, a corporate network with Internet access only via an HTTP
   proxy, or a CoAP application running in a web browser without access
   to connectivity means other than HTTP and WebSockets.

   This document specifies how to access resources using CoAP requests
   and responses over the WebSocket Protocol.  This allows connectivity-
   limited applications to obtain end-to-end CoAP connectivity either by