AiVibeConstrained Application Protocol (CoAP)
CoAP is an IETF web transfer protocol, specified in RFC 7252, designed for constrained devices and networks, offering a REST-style request-response model similar to HTTP over lightweight UDP messaging.
CoAP uses methods such as GET, PUT, POST and DELETE on resources identified by URIs, like HTTP, but with a compact binary header and UDP transport. Messages can be confirmable, requiring acknowledgement and retransmission, or non-confirmable. The Observe extension, RFC 7641, lets a client register interest in a resource and receive notifications when it changes, and resource discovery uses the CoRE Link Format. Security is provided by DTLS, and CoAP over TCP and WebSockets is also defined.
CoAP targets battery-powered sensors, actuators and microcontrollers on low-power networks such as 6LoWPAN, Thread and cellular IoT links, where the overhead of HTTP and TCP is too high. It is the main transport beneath the OMA LwM2M device management standard and is used in smart metering, building automation and environmental monitoring. Proxies can translate between CoAP and HTTP.
Compared with MQTT, CoAP is request-response and does not require a broker, though Observe offers a form of publish-subscribe. UDP traversal of firewalls and NAT can be harder than TCP, and DTLS session management adds complexity on constrained devices. OSCORE, RFC 8613, adds object-level security that can be maintained across proxies.
Key points
- IETF protocol specified in RFC 7252
- REST-style methods and URIs over UDP with a compact header
- Observe (RFC 7641) delivers change notifications
- Secured with DTLS; OSCORE adds object-level security
- Main transport beneath the OMA LwM2M device management standard
Where AiVibe comes in
AiAmbA IoT is AiVibe's edge protocol layer: it discovers devices and normalises industrial signals, with supported protocols including Siemens S7, Mitsubishi MC, Delta Modbus, OPC UA and MQTT, and driver availability confirmed per installation. Writes to machines are deny-by-default.