CoAP (Constrained Application Protocol) over TCP, TLS, and WebSockets

Approval announcement
Draft of message to be sent after approval:

From: The IESG <>
To: IETF-Announce <>
Cc: The IESG <>,,,, Jaime Jimenez <>,,,
Subject: Protocol Action: 'CoAP (Constrained Application Protocol) over TCP, TLS, and WebSockets' to Proposed Standard (draft-ietf-core-coap-tcp-tls-11.txt)

The IESG has approved the following document:
- 'CoAP (Constrained Application Protocol) over TCP, TLS, and WebSockets'
  (draft-ietf-core-coap-tcp-tls-11.txt) as Proposed Standard

This document is the product of the Constrained RESTful Environments Working

The IESG contact persons are Adam Roach, Alexey Melnikov and Ben Campbell.

A URL of this Internet Draft is:

Technical Summary

   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.  It also formally updates RFC 7641 for use with these
   transports and RFC 7959 to enable the use of larger messages over a
   reliable transport.

Working Group Summary

   The document has gone through multiple expert reviews over
   the years and was last presented on multiple IETF sessions.

   The discussion on whether the document should use coaps+ws://
   versa coap+wss:// URI scheme was rather protracted, but the WG
   finally came to a conclusion.

   The decision to allocate several new URI schemes for different
   underlying transports has caused some controversy, but was finally
   settled after a discussion with IESG and URI experts.

Document Quality

   Several vendors are interested in implementing the specification.


   Document Shepherd: Jaime Jiménez <>
   Responsible Area Director: Alexey Melnikov