@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.},
}