Skip to main content

Observe Notifications as CoAP Multicast Responses

Document Type Replaced Internet-Draft (candidate for core WG)
Expired & archived
Authors Marco Tiloca , Rikard Höglund , Christian Amsüss , Francesca Palombini
Last updated 2021-03-12 (Latest revision 2021-02-22)
Replaced by draft-ietf-core-observe-multicast-notifications
RFC stream Internet Engineering Task Force (IETF)
Intended RFC status (None)
Additional resources Mailing list discussion
Stream WG state Call For Adoption By WG Issued
Document shepherd (None)
IESG IESG state Replaced by draft-ietf-core-observe-multicast-notifications
Consensus boilerplate Unknown
Telechat date (None)
Responsible AD (None)
Send notices to (None)

This Internet-Draft is no longer active. A copy of the expired Internet-Draft is available in these formats:


The Constrained Application Protocol (CoAP) allows clients to "observe" resources at a server, and receive notifications as unicast responses upon changes of the resource state. In some use cases, such as based on publish-subscribe, it would be convenient for the server to send a single notification addressed to all the clients observing a same target resource. This document updates RFC7252 and RFC7641, and defines how a server sends observe notifications as response messages over multicast, synchronizing all the observers of a same resource on a same shared Token value. Besides, this document defines how Group OSCORE can be used to protect multicast notifications end-to-end between the server and the observer clients.


Marco Tiloca
Rikard Höglund
Christian Amsüss
Francesca Palombini

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)