One document matched: draft-ma-core-dhcp-pd-00.txt

CoRE Working Group                                                 Y. Ma
Internet-Draft                                                     X. He
Intended status: Informational              Hitachi (China) Research and
Expires: April 3, 2012                           Development Corporation
                                                                  Z. Cao
                                                            China Mobile
                                                                Oct 2011


                  dhcp option for CoAP Proxy Discovery
                        draft-ma-core-dhcp-pd-00

Abstract

   CoAP utilizes DNS to discovery the IP address of the CoAP server.
   However DNS is heavy for the most resource constrained end-points.
   In this case the assistance from CoAP proxy or research directory
   (RD) is needed for CoAP transaction.  This specification proposes to
   define one new dhcp option for proxy/RD discovery for the most
   resource constrained end-points.

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 April 3, 2012.

Copyright Notice

   Copyright (c) 2011 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



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   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  . . . . . . . . . . . . . . . . . . . . . . . . . 3
     1.1.  Conventions used in this document . . . . . . . . . . . . . 3
   2.  dhcp option for proxy discovery . . . . . . . . . . . . . . . . 3
   3.  Security Considerations . . . . . . . . . . . . . . . . . . . . 4
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4
   5.  Normative References  . . . . . . . . . . . . . . . . . . . . . 4
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . . 4




































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1.  Introduction

   CoAP [I-D.ietf-core-coap] is a RESTful protocol designed for
   constrained devices.  The ultimate goal of CoAP is to enable the "Web
   of Things" concept, which connects the smart sensor network with the
   global internet.

   CoAP utilizes DNS for CoAP server IP address discovery.  However in
   some circumstances, DNS is heavy to be implemented in the resource
   constrained nodes.  In this case the assistance from CoAP proxy is
   needed for CoAP transaction.

   Also in many M2M scenarios, direct discovery of resources is not
   practical due to sleeping nodes, disperse networks, or networks where
   multicast traffic is inefficient.  These problems can be solved by
   employing an entity called a Resource Directory
   (RD)[I-D.shelby-core-resource-directory], which hosts descriptions of
   resources held on other servers, allowing lookups to be performed for
   those resources .

   Before the CoAP sensor makes use of the CoAP proxy or RD, it must
   know the location of the proxy or RD.  There can be multiple ways to
   discover the proxy's location, including both static and dynamic
   methods.  Static configuration is a straightforward way for the
   client to access the server.  However, in many situations, static
   configuration is not enough to meet the requirements.

1.1.  Conventions used in this document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL","SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119]


2.  dhcp option for proxy discovery

   dhcp [RFC2131] provides dynamic methods to deliver configuration
   information to the end node. dhcp options [RFC2132] are defined to
   specify server information.  This document specifies one new dhcp
   option for CoAP proxy/rd discovery.

   The CoAP proxy/rd option specifies a list of CoAP proxy or Research
   Directory servers available to the client.  Servers SHOULD be listed
   in order of preference.

   The code for the name server option is x.  The minimum length for
   this option is 4 octets, and the length MUST always be a multiple of
   4.



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             Code   Len         Address 1               Address 2
            +-----+-----+-----+-----+-----+-----+-----+-----+--
            |  x  |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
            +-----+-----+-----+-----+-----+-----+-----+-----+--



                           CoAP proxy/rd option


3.  Security Considerations

   TBD.


4.  IANA Considerations

   This document needs to register one new dhcp option number at IANA.


5.  Normative References

   [I-D.ietf-core-coap]
              Shelby, Z., Hartke, K., Bormann, C., and B. Frank,
              "Constrained Application Protocol (CoAP)",
              draft-ietf-core-coap-07 (work in progress), July 2011.

   [I-D.shelby-core-resource-directory]
              Shelby, Z. and S. Krco, "CoRE Resource Directory",
              draft-shelby-core-resource-directory-01 (work in
              progress), September 2011.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2131]  Droms, R., "Dynamic Host Configuration Protocol",
              RFC 2131, March 1997.

   [RFC2132]  Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor
              Extensions", RFC 2132, March 1997.











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Authors' Addresses

   Yuanchen Ma
   Hitachi (China) Research and Development Corporation
   301, Tower C North, Raycom, 2 Kexuyuan Nanlu, Haidian District
   Beijing 100190
   China

   Email: ycma@hitachi.cn


   Xuan He
   Hitachi (China) Research and Development Corporation
   301, Tower C North, Raycom, 2 Kexuyuan Nanlu, Haidian District
   Beijing 100190
   China

   Email: xhe@hitachi.cn


   Zhen Cao
   China Mobile
   Unit2, 28 Xuanwumenxi Ave,Xuanwu District
   Beijing 100053
   China

   Email: zehn.cao@gmail.com
























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