[Docs] [txt|pdf] [Tracker] [Email] [Nits]

Versions: 00

CoRE Working Group                                                 K. Li
Internet-Draft                                             Alibaba Group
Intended status: Standards Track                               A. Rahman
Expires: January 9, 2017                                    InterDigital
                                                         C. Bormann, Ed.
                                                 Universitaet Bremen TZI
                                                           July 08, 2016


              Representing CoRE Groupcomm Formats in CBOR
                  draft-bormann-core-groupcomm-cbor-00

Abstract

   Group Communication for the Constrained Application Protocol
   (RFC7390) defines a number of JSON formats for controlling
   communication between groups of nodes employing the Constrained
   Application Protocol (CoAP).  This specification defines CBOR
   variants of these formats.

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 http://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 January 9, 2017.

Copyright Notice

   Copyright (c) 2016 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
   (http://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



Li, et al.               Expires January 9, 2017                [Page 1]


Internet-Draft              Groupcomm-in-CBOR                  July 2016


   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 . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Group Communication Management Objects in CBOR  . . . . . . .   3
     2.1.  Background  . . . . . . . . . . . . . . . . . . . . . . .   3
     2.2.  Information Model . . . . . . . . . . . . . . . . . . . .   3
     2.3.  Mapping . . . . . . . . . . . . . . . . . . . . . . . . .   3
     2.4.  Group Communication Example . . . . . . . . . . . . . . .   3
   3.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   5.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   6
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   6
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .   6
     6.2.  Informative References  . . . . . . . . . . . . . . . . .   6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   (See abstract for now.)

1.1.  Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   [RFC2119] when they appear in ALL CAPS.  These words may also appear
   in this document in lower case as plain English words, absent their
   normative meanings.

   The term "byte" is used in its now customary sense as a synonym for
   "octet".

   CoAP: Constrained Application Protocol [RFC7252]

   CBOR: Concise Binary Object Representation [RFC7049]

   CoRE: Constrained RESTful Environments, the field of work underlying
   [RFC6690], [RFC7049], [RFC7252], and [RFC7641]

   IoT: Internet of Things

   JSON: JavaScript Object Notation [RFC7159]




Li, et al.               Expires January 9, 2017                [Page 2]


Internet-Draft              Groupcomm-in-CBOR                  July 2016


2.  Group Communication Management Objects in CBOR

2.1.  Background

   The CoAP Group Communications specification [RFC7390] defines group
   management objects in JSON format.  These objects are used to
   represent IP multicast group information for CoAP endpoints.  See
   [I-D.ietf-core-resource-directory] for more examples of using these
   objects.

2.2.  Information Model

   This section discusses the information model underlying the CoAP
   Group Communication management object payload.

   A group membership JSON object contains one or more key/value pairs,
   and represents a single IP multicast group membership for the CoAP
   endpoint.  Each key/value pair is encoded as a member of the JSON
   object, where the key is the member name and the value is the
   member's value.

   The information model of the CoAP Group Communication management
   object can be summarized in CDDL [I-D.greevenbosch-appsawg-cbor-cddl]
   below:

   collection = { * index => membership }
   index = tstr .regexp "[A-Za-z0-9]{1,2}"
   membership = {
     ? n: groupname,
     ? a: groupaddress,
   }
   groupname = tstr    ; host [":" port]
   groupaddress = tstr ; IPv4address [ ":" port ]
                       ; / "[" IPv6address "]" [":" port ]

               Figure 1: CoAP Group Communication Data Model

2.3.  Mapping

   The objective of the mapping defined in this section is to map
   information from the JSON formats specified in [RFC7390] into CBOR
   format, using the rules of Section 4.2 of [RFC7049].

2.4.  Group Communication Example







Li, et al.               Expires January 9, 2017                [Page 3]


Internet-Draft              Groupcomm-in-CBOR                  July 2016


   { "8" :{ "a": "[ff15::4200:f7fe:ed37:14ca]" },
     "11":{ "n": "sensors.floor1.west.bldg6.example.com",
            "a": "[ff15::4200:f7fe:ed37:25cb]" },
     "12":{ "n": "All-Devices.floor1.west.bldg6.example.com",
            "a": "[ff15::4200:f7fe:ed37:abcd]:4567" }
   }

            Figure 2: Example from section 2.6.2.4 of [RFC7390]

   becomes:









































Li, et al.               Expires January 9, 2017                [Page 4]


Internet-Draft              Groupcomm-in-CBOR                  July 2016


  a3                                # map(3)
     61                             # text(1)
        38                          # "8"
     a1                             # map(1)
        61                          # text(1)
           61                       # "a"
        78 1b                       # text(27)
           5b666631353a3a343230
           303a663766653a656433
           373a313463615d           # "[ff15::4200:f7fe:ed37:14ca]"
     62                             # text(2)
        3131                        # "11"
     a2                             # map(2)
        61                          # text(1)
           6e                       # "n"
        78 25                       # text(37)
           73656e736f72732e666c
           6f6f72312e776573742e
           626c6467362e6578616d
           706c652e636f6d     # "sensors.floor1.west.bldg6.example.com"
        61                          # text(1)
           61                       # "a"
        78 1b                       # text(27)
           5b666631353a3a343230
           303a663766653a656433
           373a323563625d           # "[ff15::4200:f7fe:ed37:25cb]"
     62                             # text(2)
        3132                        # "12"
     a2                             # map(2)
        61                          # text(1)
           6e                       # "n"
        78 29                       # text(41)
           416c6c2d446576696365
           732e666c6f6f72312e77
           6573742e626c6467362e
           6578616d706c652e636f
           6d              # "All-Devices.floor1.west.bldg6.example.com"
        61                          # text(1)
           61                       # "a"
        78 20                       # text(32)
           5b666631353a3a343230
           303a663766653a656433
           373a616263645d3a34353637 # "[ff15::4200:f7fe:ed37:abcd]:4567"


      Figure 3: Group Communication Management Object Encoded in CBOR





Li, et al.               Expires January 9, 2017                [Page 5]


Internet-Draft              Groupcomm-in-CBOR                  July 2016


3.  IANA Considerations

   This specification registers the following additional Internet Media
   Types:

   TBD

4.  Security Considerations

   The security considerations relevant to the data models of [RFC7390],
   as well as those of [RFC7049] and [RFC7159] apply.

5.  Acknowledgements

   Special thanks to Bert Greevenbosch who was an author on the initial
   version of a contributing document as well as the original author on
   the CDDL notation.

   Hannes Tschofenig made many helpful suggestions for improving this
   document, in particular splitting off the [RFC7390] parts from
   [I-D.ietf-core-links-json].

6.  References

6.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.

   [RFC6690]  Shelby, Z., "Constrained RESTful Environments (CoRE) Link
              Format", RFC 6690, DOI 10.17487/RFC6690, August 2012,
              <http://www.rfc-editor.org/info/rfc6690>.

   [RFC7049]  Bormann, C. and P. Hoffman, "Concise Binary Object
              Representation (CBOR)", RFC 7049, DOI 10.17487/RFC7049,
              October 2013, <http://www.rfc-editor.org/info/rfc7049>.

   [RFC7159]  Bray, T., Ed., "The JavaScript Object Notation (JSON) Data
              Interchange Format", RFC 7159, DOI 10.17487/RFC7159, March
              2014, <http://www.rfc-editor.org/info/rfc7159>.

6.2.  Informative References







Li, et al.               Expires January 9, 2017                [Page 6]


Internet-Draft              Groupcomm-in-CBOR                  July 2016


   [I-D.greevenbosch-appsawg-cbor-cddl]
              Vigano, C. and H. Birkholz, "CBOR data definition language
              (CDDL): a notational convention to express CBOR data
              structures", draft-greevenbosch-appsawg-cbor-cddl-08 (work
              in progress), March 2016.

   [I-D.ietf-core-links-json]
              Li, K., Rahman, A., and D. Bormann, "Representing CoRE
              Formats in JSON and CBOR", draft-ietf-core-links-json-05
              (work in progress), April 2016.

   [I-D.ietf-core-resource-directory]
              Shelby, Z., Koster, M., Bormann, D., and P. Stok, "CoRE
              Resource Directory", draft-ietf-core-resource-directory-08
              (work in progress), July 2016.

   [RFC7252]  Shelby, Z., Hartke, K., and C. Bormann, "The Constrained
              Application Protocol (CoAP)", RFC 7252,
              DOI 10.17487/RFC7252, June 2014,
              <http://www.rfc-editor.org/info/rfc7252>.

   [RFC7390]  Rahman, A., Ed. and E. Dijk, Ed., "Group Communication for
              the Constrained Application Protocol (CoAP)", RFC 7390,
              DOI 10.17487/RFC7390, October 2014,
              <http://www.rfc-editor.org/info/rfc7390>.

   [RFC7641]  Hartke, K., "Observing Resources in the Constrained
              Application Protocol (CoAP)", RFC 7641,
              DOI 10.17487/RFC7641, September 2015,
              <http://www.rfc-editor.org/info/rfc7641>.

Authors' Addresses

   Kepeng LI
   Alibaba Group
   Wenyixi Road, Yuhang District
   Hangzhou, Zhejiang  311121
   China

   Email: kepeng.lkp@alibaba-inc.com











Li, et al.               Expires January 9, 2017                [Page 7]


Internet-Draft              Groupcomm-in-CBOR                  July 2016


   Akbar Rahman
   InterDigital Communications, LLC
   1000 Sherbrooke Street West
   Montreal, Quebec  H3A 3G4
   Canada

   Phone: +1-514-585-0761
   Email: akbar.rahman@interdigital.com


   Carsten Bormann (editor)
   Universitaet Bremen TZI
   Postfach 330440
   Bremen  D-28359
   Germany

   Phone: +49-421-218-63921
   Email: cabo@tzi.org

































Li, et al.               Expires January 9, 2017                [Page 8]


Html markup produced by rfcmarkup 1.129b, available from https://tools.ietf.org/tools/rfcmarkup/