CoAP over TCP, TLS, and WebSockets
RFC 8323, “CoAP over TCP, TLS, and WebSockets”, is a Proposed Standard document published in February 2018 by C. Bormann, S. Lemay, H. Tschofenig, K. Hartke, B. Silverajan, B. Raymor. It updates RFC 7641, RFC 7959. It has since been updated by RFC 8974. The canonical text is published by the RFC Editor.
Abstract
The Constrained Application Protocol (CoAP), although inspired by HTTP, was designed to use UDP instead of TCP. The message layer of CoAP over UDP 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 Transport Layer Security (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.
What “Proposed Standard” means
An entry-level standards-track specification: stable, peer-reviewed and a solid basis for implementation, though it may still evolve before becoming an Internet Standard.
The canonical text of RFC 8323 is hosted at rfc-editor.org. Available in TXT,HTML.
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