Proxy Operations for CoAP Group Communication
draft-tiloca-core-groupcomm-proxy-00

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

• Versions
• 00
• 01
• 02
• 03

CoRE Working Group                                             M. Tiloca
Internet-Draft                                                   RISE AB
Intended status: Standards Track                                 E. Dijk
Expires: September 10, 2020                            IoTconsultancy.nl
                                                          March 09, 2020

             Proxy Operations for CoAP Group Communication
                  draft-tiloca-core-groupcomm-proxy-00

Abstract

   This document specifies the operations performed by a forward-proxy,
   when using the Constrained Application Protocol (CoAP) in group
   communication scenarios.  Proxy operations involve the processing of
   individual responses from servers, as reply to a single request sent
   by the client over unicast to the proxy, and then distributed by the
   proxy over IP multicast to the servers.  When receiving the different
   responses via the proxy, the client is able to distinguish them and
   their originator servers, by acquiring their addressing information.

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 September 10, 2020.

Copyright Notice

   Copyright (c) 2020 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

Tiloca & Dijk          Expires September 10, 2020               [Page 1]
Internet-Draft  Proxy Operations for Group Communication      March 2020

   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 . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  The Multicast-Signaling Option  . . . . . . . . . . . . . . .   3
   3.  The Response-Forwarding Option  . . . . . . . . . . . . . . .   4
   4.  Requirements and Objectives . . . . . . . . . . . . . . . . .   5
   5.  Protocol Description  . . . . . . . . . . . . . . . . . . . .   6
     5.1.  Request Sending . . . . . . . . . . . . . . . . . . . . .   6
     5.2.  Request Processing at the Proxy . . . . . . . . . . . . .   7
     5.3.  Request and Response Processing at the Server . . . . . .   8
     5.4.  Response Processing at the Proxy  . . . . . . . . . . . .   8
     5.5.  Response Processing at the Client . . . . . . . . . . . .   9
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  10
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
     7.1.  CoAP Option Numbers Registry  . . . . . . . . . . . . . .  10
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  11
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  11
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  12
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .  12
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  12

1.  Introduction

   The Constrained Application Protocol (CoAP) [RFC7252] allows the
   presence of forward-proxies, as intermediary entities supporting
   clients to perform requests on their behalf.

   CoAP supports also group communication over IP multicast
   [I-D.dijk-core-groupcomm-bis], where a group request can be addressed
   to multiple recipient servers, each of which may reply with an
   individual unicast response.  As discussed in Section 2.3.3 of
   [I-D.dijk-core-groupcomm-bis], this group communication scenario
   poses a number of issues and limitations to proxy operations.

   In particular, the client sends a single unicast request to the
   proxy, which the proxy forwards to a group of servers over IP
   multicast.  Later on, the proxy delivers back to the client multiple
   responses to the original unicast request.  As defined by [RFC7252]
   the multiple responses are delivered to the client inside separate
   CoAP messages, all matching (by Token) to the client's original