@misc{rfc7641, series = {Request for Comments}, number = 7641, howpublished = {RFC 7641}, publisher = {RFC Editor}, doi = {10.17487/RFC7641}, url = {https://www.rfc-editor.org/info/rfc7641}, author = {Klaus Hartke}, title = {{Observing Resources in the Constrained Application Protocol (CoAP)}}, pagetotal = 30, year = 2015, month = sep, abstract = {The Constrained Application Protocol (CoAP) is a RESTful application protocol for constrained nodes and networks. The state of a resource on a CoAP server can change over time. This document specifies a simple protocol extension for CoAP that enables CoAP clients to "observe" resources, i.e., to retrieve a representation of a resource and keep this representation updated by the server over a period of time. The protocol follows a best-effort approach for sending new representations to clients and provides eventual consistency between the state observed by each client and the actual resource state at the server.}, }