Dynamic Host Configuration Protocol (DHCPv4 and DHCPv6) Option for Civic Addresses Configuration Information
RFC 4776

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Network Working Group                                     H. Schulzrinne
Request for Comments: 4776                                   Columbia U.
Obsoletes: 4676                                            November 2006
Category: Standards Track

    Dynamic Host Configuration Protocol (DHCPv4 and DHCPv6) Option
             for Civic Addresses Configuration Information

Status of This Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The IETF Trust (2006).

RFC Editor Note

   RFC 4776 is being published to correct an error in the assignment of
   the numeric value of the DHCPv6 option-code in RFC 4676 (Section
   3.2).  This document obsoletes RFC 4676.

Abstract

   This document specifies a Dynamic Host Configuration Protocol (DHCPv4
   and DHCPv6) option containing the civic location of the client or the
   DHCP server.  The Location Configuration Information (LCI) includes
   information about the country, administrative units such as states,
   provinces, and cities, as well as street addresses, postal community
   names, and building information.  The option allows multiple
   renditions of the same address in different scripts and languages.

Schulzrinne                 Standards Track                     [Page 1]
RFC 4776                       DHCP Civic                  November 2006

Table of Contents

   1. Introduction ....................................................2
   2. Terminology .....................................................5
   3. Format of the DHCP Civic Location Option ........................5
      3.1. Overall Format for DHCPv4 ..................................5
      3.2. Overall Format for DHCPv6 ..................................6
      3.3. Element Format .............................................7
      3.4. Civic Address Components ...................................7
   4. Postal Addresses ...............................................13
   5. Example ........................................................14
   6. Security Considerations ........................................15
   7. IANA Considerations ............................................15
   8. References .....................................................16
      8.1. Normative References ......................................16
      8.2. Informative References ....................................17
   Acknowledgements ..................................................17

1.  Introduction

   Many end system services can benefit by knowing the approximate
   location of the end device.  In particular, IP telephony devices need
   to know their location to contact the appropriate emergency response
   agency and to be found by emergency responders.

   There are two common ways to identify the location of an object,
   either through geospatial coordinates or by so-called civic
   addresses.  Geospatial coordinates indicate longitude, latitude, and
   altitude, while civic addresses indicate a street address.

   The civic address is commonly, but not necessarily, closely related
   to the postal address, used by the local postal service to deliver
   mail.  However, not all postal addresses correspond to street
   addresses.  For example, the author's address is a postal address
   that does not appear on any street or building sign.  Naturally, post
   office boxes would be unsuitable for the purposes described here.
   The term 'civil address' or 'jurisdictional address' is also
   sometimes used instead of civic address.  This document mainly
   supports civic addresses, but allows the postal community name to be
   indicated if it differs from the civic name.

   A related document [15] describes a DHCPv4 [2] option for conveying
   geospatial information to a device.  This document describes how
   DHCPv4 and DHCPv6 [6] can be used to convey the civic and postal
   address to devices.  Both geospatial and civic formats can be used
   simultaneously, increasing the chance to deliver accurate and timely

Schulzrinne                 Standards Track                     [Page 2]
RFC 4776                       DHCP Civic                  November 2006

   location information to emergency responders.  The reader should also
   be familiar with the concepts in [11], as many of the protocol
   elements below are designed to dovetail with PIDF-LO elements.

   This document only defines the delivery of location information from
   the DHCP server to the client, due to security concerns related to
   using DHCP to update the database.  Within the GEOPRIV architecture
   as defined by RFC 3693 [9], the defined mechanism in this document