Observe Notifications as CoAP Multicast Responses
draft-tiloca-core-observe-multicast-notifications-01

• Status
• IESG evaluation record
• IESG writeups
• Email expansions
• History

• Versions
• 00
• 01

CoRE Working Group                                             M. Tiloca
Internet-Draft                                               R. Hoeglund
Updates: 7252, 7390, 7641 (if approved)                          RISE AB
Intended status: Standards Track                              C. Amsuess
Expires: May 7, 2020
                                                            F. Palombini
                                                             Ericsson AB
                                                       November 04, 2019

           Observe Notifications as CoAP Multicast Responses
          draft-tiloca-core-observe-multicast-notifications-01

Abstract

   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 to all the clients observing a
   same target resource.  This document defines how a CoAP server sends
   observe notifications as response messages over multicast, by
   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 from the CoAP
   server to the multiple observer clients.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on May 7, 2020.

Tiloca, et al.             Expires May 7, 2020                  [Page 1]
Internet-Draft       Observe Multicast Notifications       November 2019

Copyright Notice

   Copyright (c) 2019 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   4
   2.  Server-Side Requirements  . . . . . . . . . . . . . . . . . .   4
   3.  Client-Side Requirements  . . . . . . . . . . . . . . . . . .   6
   4.  Example . . . . . . . . . . . . . . . . . . . . . . . . . . .   7
   5.  Protection of Multicast Notifications with Group OSCORE . . .   9
     5.1.  OSCORE Group in Informative Response  . . . . . . . . . .   9
     5.2.  Server-Side Requirements  . . . . . . . . . . . . . . . .  11
     5.3.  Client-Side Requirements  . . . . . . . . . . . . . . . .  12
   6.  Example with Group OSCORE . . . . . . . . . . . . . . . . . .  12
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  14
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  15
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  15
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  15
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  16
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .  17
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  17

1.  Introduction

   The Constrained Application Protocol (CoAP) [RFC7252] has been
   extended with a number of mechanisms, including resource Observation
   [RFC7641].  This enables CoAP clients to register at a CoAP server as
   "observers" of a resource, and hence being automatically notified
   with an unsolicited response upon changes of the resource state.

   CoAP supports group communication over IP multicast [RFC7390], and
   [I-D.dijk-core-groupcomm-bis] has been enabling Observe registration
   requests over multicast, in order for clients to efficiently register
   as observers of a resource hosted at multiple servers.

Tiloca, et al.             Expires May 7, 2020                  [Page 2]
Internet-Draft       Observe Multicast Notifications       November 2019