HTTP-Enabled Location Delivery (HELD)
RFC 5985

Internet Engineering Task Force (IETF)                    M. Barnes, Ed.
Request for Comments: 5985                                       Polycom
Category: Standards Track                                 September 2010
ISSN: 2070-1721

                 HTTP-Enabled Location Delivery (HELD)

Abstract

   This document defines a Layer 7 Location Configuration Protocol (L7
   LCP) and describes the use of HTTP and HTTP/TLS as transports for the
   L7 LCP.  The L7 LCP is used for retrieving location information from
   a server within an access network.  It includes options for
   retrieving location information in two forms: by value and by
   reference.  The protocol is an extensible application-layer protocol
   that is independent of the session layer.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc5985.

Copyright Notice

   Copyright (c) 2010 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   described in the Simplified BSD License.

Barnes                       Standards Track                    [Page 1]
RFC 5985                          HELD                    September 2010

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Conventions and Terminology  . . . . . . . . . . . . . . . . .  3
   3.  Overview and Scope . . . . . . . . . . . . . . . . . . . . . .  4
   4.  Protocol Overview  . . . . . . . . . . . . . . . . . . . . . .  5
     4.1.  Device Identifiers, NAT and VPNs . . . . . . . . . . . . .  6
       4.1.1.  Devices and VPNs . . . . . . . . . . . . . . . . . . .  6
       4.1.2.  LIS Handling of NATs and VPNs  . . . . . . . . . . . .  7
     4.2.  Location by Value  . . . . . . . . . . . . . . . . . . . .  7
     4.3.  Location by Reference  . . . . . . . . . . . . . . . . . .  8
   5.  Protocol Description . . . . . . . . . . . . . . . . . . . . .  8
     5.1.  Location Request . . . . . . . . . . . . . . . . . . . . .  9
     5.2.  Location Response  . . . . . . . . . . . . . . . . . . . .  9
     5.3.  Indicating Errors  . . . . . . . . . . . . . . . . . . . .  9
   6.  Protocol Parameters  . . . . . . . . . . . . . . . . . . . . . 10
     6.1.  "responseTime" Parameter . . . . . . . . . . . . . . . . . 10
     6.2.  "locationType" Parameter . . . . . . . . . . . . . . . . . 11
       6.2.1.  "exact" Attribute  . . . . . . . . . . . . . . . . . . 13
     6.3.  "code" Parameter . . . . . . . . . . . . . . . . . . . . . 13
     6.4.  "message" Parameter  . . . . . . . . . . . . . . . . . . . 14
     6.5.  "locationUriSet" Parameter . . . . . . . . . . . . . . . . 14
       6.5.1.  "locationURI" Parameter  . . . . . . . . . . . . . . . 14
       6.5.2.  "expires" Parameter  . . . . . . . . . . . . . . . . . 15
     6.6.  "Presence" Parameter (PIDF-LO) . . . . . . . . . . . . . . 16
   7.  XML Schema . . . . . . . . . . . . . . . . . . . . . . . . . . 16
   8.  HTTP Binding . . . . . . . . . . . . . . . . . . . . . . . . . 20
   9.  Security Considerations  . . . . . . . . . . . . . . . . . . . 22
     9.1.  Assuring That the Proper LIS Has Been Contacted  . . . . . 23
     9.2.  Protecting Responses from Modification . . . . . . . . . . 23
     9.3.  Privacy and Confidentiality  . . . . . . . . . . . . . . . 23
   10. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
     10.1. Examples of HTTPS Messages . . . . . . . . . . . . . . . . 25
     10.2. Example of a Simple Location Request . . . . . . . . . . . 26
     10.3. An Example of a Location Request for Multiple Location
           Types  . . . . . . . . . . . . . . . . . . . . . . . . . . 27
   11. IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 28