[Docs] [txt|pdf|xml|html] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: (draft-polk-ecrit-dhc-lost-discovery) 00 01 02 03 RFC 5223

ECRIT                                                     H. Schulzrinne
Internet-Draft                                       Columbia University
Intended status:  Standards Track                                J. Polk
Expires:  November 30, 2008                                        Cisco
                                                           H. Tschofenig
                                                  Nokia Siemens Networks
                                                            May 29, 2008


 A Dynamic Host Configuration Protocol (DHCP) based Location-to-Service
            Translation Protocol (LoST) Discovery Procedure
               draft-ietf-ecrit-dhc-lost-discovery-03.txt

Status of this Memo

   By submitting this Internet-Draft, each author represents that any
   applicable patent or other IPR claims of which he or she is aware
   have been or will be disclosed, and any of which he or she becomes
   aware will be disclosed, in accordance with Section 6 of BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-
   Drafts.

   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."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/ietf/1id-abstracts.txt.

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.

   This Internet-Draft will expire on November 30, 2008.

Abstract

   The Location-to-Service Translation Protocol (LoST) describes an XML-
   based protocol for mapping service identifiers and geospatial or
   civic location information to service contact Uniform Resource
   Locators (URLs).  LoST servers can be located anywhere but a
   placement closer to the end host, e.g., in the access network, is
   desireable.  Such a LoST server placement provides benefits in
   disaster situations with intermittent network connectivity regarding
   the resiliency of emergency service communication.



Schulzrinne, et al.     Expires November 30, 2008               [Page 1]

Internet-Draft          DHCP-based LoST Discovery               May 2008


   This document describes how a LoST client can discover a LoST server
   using the Dynamic Host Configuration Protocol (DHCP).


Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3
   3.  Domain Name Encoding  . . . . . . . . . . . . . . . . . . . . . 3
   4.  LoST Server DHCPv4 Option . . . . . . . . . . . . . . . . . . . 4
   5.  LoST Server DHCPv6 Option . . . . . . . . . . . . . . . . . . . 5
   6.  Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6
     7.1.  IANA Consideration for DHCPv4 Option  . . . . . . . . . . . 6
     7.2.  IANA Consideration for DHCPv6 Option  . . . . . . . . . . . 6
   8.  Security Considerations . . . . . . . . . . . . . . . . . . . . 6
   9.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . 6
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . . . 7
     10.1. Normative References  . . . . . . . . . . . . . . . . . . . 7
     10.2. Informative References  . . . . . . . . . . . . . . . . . . 7
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . . 8
   Intellectual Property and Copyright Statements  . . . . . . . . . . 9





























Schulzrinne, et al.     Expires November 30, 2008               [Page 2]

Internet-Draft          DHCP-based LoST Discovery               May 2008


1.  Introduction

   The Location-to-Service Translation Protocol (LoST)
   [I-D.ietf-ecrit-lost] describes an XML-based protocol for mapping
   service identifiers and geospatial or civic location information to
   service contact Uniform Resource Locators (URLs).

   In order to interact with a LoST server, the LoST client eventually
   needs to discover the server's IP address.  Several mechanisms can be
   used to learn this address, including manual configuration.  In
   environments where the access network itself either deploys a LoST
   server or knows a third party that operates a LoST server, DHCP can
   provide the end host with a domain name.  This domain name is then
   used as input to the DNS-based resolution mechanism described in LoST
   [I-D.ietf-ecrit-lost] that reuses the URI-enabled NAPTR specification
   (see [RFC4848]).

   This document specifies a DHCPv4 and a DHCPv6 option that allows LoST
   clients to discover local LoST servers.

   Section 2 provides terminology.  Section 3 shows the encoding of the
   domain name.  Section 4 describes the DHCPv4 option while Section 5
   describes the DHCPv6 option, with the same functionality.  IANA and
   Security Considerations complete the document in Section 7 and
   Section 8.


2.  Terminology

   In this document, the key words "MUST", "MUST NOT", "REQUIRED",
   "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",
   and "OPTIONAL" are to be interpreted as described in RFC 2119
   [RFC2119].

   Within this document, we use terminology from [RFC5012] and
   [I-D.ietf-ecrit-lost].


3.  Domain Name Encoding

   This section describes the encoding of the domain name used in the
   DHCPv4 option shown in Section 4 and also used in the DHCPv6 option
   shown in Section 5.

   The domain name is encoded according to Section 3.1 of RFC 1035
   [RFC1035] whereby each label is represented as a one octet length
   field followed by that number of octets.  Since every domain name
   ends with the null label of the root, a domain name is terminated by



Schulzrinne, et al.     Expires November 30, 2008               [Page 3]

Internet-Draft          DHCP-based LoST Discovery               May 2008


   a length byte of zero.  The high order two bits of every length octet
   MUST be zero, and the remaining six bits of the length field limit
   the label to 63 octets or less.  To simplify implementations, the
   total length of a domain name (i.e., label octets and label length
   octets) is restricted to 255 octets or less.


4.  LoST Server DHCPv4 Option

   The LoST server DHCPv4 option carries a DNS (RFC 1035 [RFC1035])
   fully-qualified domain name to be used by the LoST client to locate a
   LoST server.

   The DHCP option for this encoding has the following format:

         Code    Len   LoST Server Domain Name
         +-----+-----+-----+-----+-----+-----+-----+----
         | TBD1|  n  |  s1 |  s2 |  s3 |  s4 | s5  |  ...
         +-----+-----+-----+-----+-----+-----+-----+----

                     Figure 1: LoST FQDN DHCPv4 Option

   The values s1, s2, s3, etc. represent the domain name labels in the
   domain name encoding.  Note that the length field in the DHCPv4
   option represents the length of the entire domain name encoding,
   whereas the length fields in the domain name encoding (see Section 3)
   is the length of a single domain name label.


      Code: OPTION_V4_LOST (TBD1)

      Len: Length of the 'LoST Server Domain Name' field
      in octets; variable.

      LoST server Domain Name: The domain name of the LoST
      server for the client to use.

   A DHCPv4 client MAY request a LoST server domain name in an Parameter
   Request List option, as described in [RFC2131].

   The encoding of the domain name is described in Section 3.

   This option contains a single doamin name, and as such MUST contain
   precisely one root label.







Schulzrinne, et al.     Expires November 30, 2008               [Page 4]

Internet-Draft          DHCP-based LoST Discovery               May 2008


5.  LoST Server DHCPv6 Option

   This section defines a DHCPv6 option to carry a domain name.

   The DHCPv6 option has the format shown in Figure 2.

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |      OPTION_V6_LOST           |         option-length         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                LoST Server Domain Name                        |
      |                              ...                              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

         Figure 2: DHCPv6 Option for LoST Server Domain Name List


      option-code: OPTION_V6_LOST (TBD2)

      option-length: Length of the 'LoST Server Domain Name' field
      in octets; variable.

      LoST server Domain Name: The domain name of the LoST
      server for the client to use.

   A DHCPv6 client MAY request a LoST server domain name in an Options
   Request Option (ORO), as described in [RFC3315].

   The encoding of the domain name is described in Section 3.

   This option contains a single doamin name, and as such MUST contain
   precisely one root label.


6.  Example

   This section shows an example of a DHCPv4 option where the DHCP
   server wants to offer the "example.com" domain name to the client as
   input to the U-NAPTR LoST discovery procedure.  This domain name
   would be encoded as follows:


   +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
   |TBD1|13 | 7 |'e'|'x'|'a'|'m'|'p'|'l'|'e'| 3 |'c'|'o'|'m'| 0 |
   +----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+

              Figure 3: Example for a LoST FQDN DHCPv4 Option



Schulzrinne, et al.     Expires November 30, 2008               [Page 5]

Internet-Draft          DHCP-based LoST Discovery               May 2008


7.  IANA Considerations

7.1.  IANA Consideration for DHCPv4 Option

   The following DHCPv4 option code for the Location-to-Service
   Translation Protocol (LoST) server option must be assigned by IANA:


       Option  Name            Value       Described in
       -----------------------------------------------
       OPTION_V4_LOST           TBD1         Section 4

7.2.  IANA Consideration for DHCPv6 Option

   IANA is requested to assign the following DHCPv6 option codes for the
   Location-to-Service Translation Protocol (LoST) options:


       Option  Name            Value       Described in
       ------------------------------------------------
       OPTION_V6_LOST           TBD2         Section 5


8.  Security Considerations

   If an adversary manages to modify the response from a DHCP server or
   insert its own response, a LoST client could be led to contact a
   rogue LoST server under the control of the adversary or be given an
   invalid address.  These threats are documented in [RFC5069].  The
   security considerations in [RFC2131], [RFC2132] and [RFC3315] are
   applicable to this document.

   With respect to the LoST security mechanisms please refer to
   [I-D.ietf-ecrit-lost].


9.  Acknowledgements

   The authors would like to thank Andrew Newton and Leslie Daigle for
   their draft review and Andy for the proposed simplifications.

   Mark Stapp and David W. Hankins did the document review for the DHC
   working group as part of the joint working group last call.

   We would like to thank Vijay K. Gurbani for the Gen-ART review.
   Furthermore, we would like to thank Russ Housley, Tim Polk, Jari
   Arkko, and Christian Vogt.




Schulzrinne, et al.     Expires November 30, 2008               [Page 6]

Internet-Draft          DHCP-based LoST Discovery               May 2008


10.  References

10.1.  Normative References

   [RFC1034]  Mockapetris, P., "Domain names - concepts and facilities",
              STD 13, RFC 1034, November 1987.

   [RFC1035]  Mockapetris, P., "Domain names - implementation and
              specification", STD 13, RFC 1035, November 1987.

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

   [RFC3315]  Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C.,
              and M. Carney, "Dynamic Host Configuration Protocol for
              IPv6 (DHCPv6)", RFC 3315, July 2003.

   [RFC3396]  Lemon, T. and S. Cheshire, "Encoding Long Options in the
              Dynamic Host Configuration Protocol (DHCPv4)", RFC 3396,
              November 2002.

10.2.  Informative References

   [I-D.ietf-ecrit-lost]
              Hardie, T., Newton, A., Schulzrinne, H., and H.
              Tschofenig, "LoST: A Location-to-Service Translation
              Protocol", draft-ietf-ecrit-lost-10 (work in progress),
              May 2008.

   [RFC4848]  Daigle, L., "Domain-Based Application Service Location
              Using URIs and the Dynamic Delegation Discovery Service
              (DDDS)", RFC 4848, April 2007.

   [RFC5012]  Schulzrinne, H. and R. Marshall, "Requirements for
              Emergency Context Resolution with Internet Technologies",
              RFC 5012, January 2008.

   [RFC5069]  Taylor, T., Tschofenig, H., Schulzrinne, H., and M.
              Shanmugam, "Security Threats and Requirements for
              Emergency Call Marking and Mapping", RFC 5069,
              January 2008.




Schulzrinne, et al.     Expires November 30, 2008               [Page 7]

Internet-Draft          DHCP-based LoST Discovery               May 2008


Authors' Addresses

   Henning Schulzrinne
   Columbia University
   Department of Computer Science
   450 Computer Science Building
   New York, NY  10027
   US

   Phone:  +1 212 939 7004
   Email:  hgs+ecrit@cs.columbia.edu
   URI:    http://www.cs.columbia.edu


   James Polk
   Cisco
   2200 East President George Bush Turnpike
   Richardson, Texas  75082
   US

   Email:  jmpolk@cisco.com


   Hannes Tschofenig
   Nokia Siemens Networks
   Linnoitustie 6
   Espoo  02600
   Finland

   Phone:  +358 (50) 4871445
   Email:  Hannes.Tschofenig@nsn.com
   URI:    http://www.tschofenig.priv.at



















Schulzrinne, et al.     Expires November 30, 2008               [Page 8]

Internet-Draft          DHCP-based LoST Discovery               May 2008


Full Copyright Statement

   Copyright (C) The IETF Trust (2008).

   This document is subject to the rights, licenses and restrictions
   contained in BCP 78, and except as set forth therein, the authors
   retain all their rights.

   This document and the information contained herein are provided on an
   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
   THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
   OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
   THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.


Intellectual Property

   The IETF takes no position regarding the validity or scope of any
   Intellectual Property Rights or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
   might or might not be available; nor does it represent that it has
   made any independent effort to identify any such rights.  Information
   on the procedures with respect to rights in RFC documents can be
   found in BCP 78 and BCP 79.

   Copies of IPR disclosures made to the IETF Secretariat and any
   assurances of licenses to be made available, or the result of an
   attempt made to obtain a general license or permission for the use of
   such proprietary rights by implementers or users of this
   specification can be obtained from the IETF on-line IPR repository at
   http://www.ietf.org/ipr.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights that may cover technology that may be required to implement
   this standard.  Please address the information to the IETF at
   ietf-ipr@ietf.org.











Schulzrinne, et al.     Expires November 30, 2008               [Page 9]


Html markup produced by rfcmarkup 1.108, available from http://tools.ietf.org/tools/rfcmarkup/