CoAP Transport Indication

The Constrained Application Protocol (CoAP, [RFC7252]) is available over different transports (UDP, DTLS, TCP, TLS, WebSockets), but lacks a way to unify these addresses. This document provides terminology and provisions based on Web Linking [RFC8288] and Service Bindings (SVCB, [RFC9460]) to express alternative transports available to a device, and to optimize exchanges using these.