RFC 8323

CoAP (Constrained Application Protocol) over TCP, TLS, and WebSockets, February 2018

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RFC 7641, RFC 7959
Updated by:
RFC 8974
C. Bormann
S. Lemay
H. Tschofenig
K. Hartke
B. Silverajan
B. Raymor, Ed.
core (wit)

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DOI:  https://doi.org/10.17487/RFC8323

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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.

For the definition of Status, see RFC 2026.

For the definition of Stream, see RFC 8729.

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