ecrit                                                           B. Rosen
Internet-Draft                                                   Neustar
Intended status: Standards Track                       November 04, 2013
Expires: May 08, 2014

            Validation of Locations Around a Planned Change


   This document defines an extension to LoST (RFC5222) that allows a
   planned change to the data in the LoST server to occur.  Records that
   previously were valid will become invalid at a date in the future,
   and new locations will become valid after the date.  The extension
   adds two elements to the <findservice> request: a URI to be used to
   inform the LIS that previously valid locations will be invalid after
   the planned change date, and add a date which requests the server to
   perform validation as of the date specified.

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
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   Internet-Drafts are draft documents valid for a maximum of six months
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   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 May 08, 2014.

Copyright Notice

   Copyright (c) 2013 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
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   ( 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

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   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
   2.  Conventions used in this document . . . . . . . . . . . . . .   3
   3.  <plannedChange> element . . . . . . . . . . . . . . . . . . .   3
   4.  <locationInvalidated> object  . . . . . . . . . . . . . . . .   4
   5.  Relax NG Schema . . . . . . . . . . . . . . . . . . . . . . .   4
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
     7.1.  Relax NG Schema Registration  . . . . . . . . . . . . . .   6
     7.2.  LoST Namespace Registration . . . . . . . . . . . . . . .   7
   8.  Normative References  . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   This document describes an update to the LoST protocol [RFC5222]
   which allows a <findservice> request to add a URI and a date to be
   used with planned changes to the underlying location information in
   the server which is used by the validation function.  The URI is
   retained by the LoST server, associated with the data record that was
   validated, and used to notify the LIS (the LoST client) when a
   location which was previously valid will become invalid.  The date is
   used by the client to ask the server to perform validation as of a
   future date.

   Validation of civic locations involves dealing with data that changes
   over time.  A typical example is a portion of a county or province
   that was not part of a municipality is "annexed" to a municipality.
   Prior to the change, the content of the PIDF A3 element would be
   blank, or represent some other value and after the change would be
   the municipality that annexed that part of the county/province.  This
   kind of annexation has an effectivity date (typically 00:00 on some

   Records in a LIS must change around these kinds of events.  The old
   record must be discarded, and a new, validated record must be loaded
   into the LIS.  It is often difficult for the LIS operator to know
   that records must be changed.  There are other circumstances where
   locations that were previously valid become invalid.  As RFC5222
   defines validation, the only way for a LIS to discover such changes
   was to periodically revalidate its entire database.  Of course, this
   would not facilitate timely changes, and also adds significant load
   to the LoST server.

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   This extension allows the client to provide a stable URI that is
   retained by the server associated with the location provided that the
   location information in the request was valid.  In the event of a
   planned change, or any other circumstance where the LI becomes
   invalid, the server sends a notification to the URI informing it of a
   change.  The notification contains the date and time when the LI
   becomes invalid.

   Ideally, the LIS will prepare a new record, to be inserted in its
   active database, that becomes valid at the precise planned event date
   and time, at which point it would also delete the old record.
   However, the new record has to be valid, and the LIS would like to
   validate it prior to the planned change event.  If it requests
   validation before the planned event, the server (without this
   extension) would inform the client that the location was invalid.
   This extension includes an optional "asOf" date and time in the
   request that allows the LoST server to provide validation as of the
   date and time specified, as opposed to the "as of now" implied in the
   current LoST protocol.

2.  Conventions used in this document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   document are to be interpreted as described in [RFC2119].

   "Server" in this document refers to the LoST server and "Client" is
   the LoST client, even when the server is performing an operation on
   the client.

3.  <plannedChange> element

   This document defines a new element to <findService> called
   'plannedChange'.  This element contains two attributes: 'uri' and
   'asOf'.  The 'uri' attribute MUST be a URI with a scheme of https.
   The URI will be stored by the server against the location in the
   request for subsequent use with the notification function defined
   below.  To minimize storage requirements of at the server, the length
   of the URI MUST be less than 256 bytes.  Each client of the server
   may only store one URI against a location, where "location" is
   defined by policy at the server, since a given unique location may
   have many combinations of LI elements that resolve to the same
   location.  If the server receives a 'uri' for the same location from
   the same client, the URI in the request replaces the URI it
   previously retained.  Policy at the server may limit how many uris it
   retains for a given location.  A new warning is defined below to be
   used to indicate that the URI has not been stored.

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4.  <locationInvalidated> object

   When the server needs to invalidate a location where the client
   provided a URI in <plannedChange>, the server sends
   <locationInvalidated> to the URI previously provided.  This is the
   notice from the server to the client that the location may be invalid
   and should be revalidated.  <locationInvalidated> contains an asOf
   attribute that specifies when the location may become invalid.  If
   the date/time in asOf is earlier than the time the
   <locationInvalidated> was sent, the location may already be invalid
   and the LIS should take immediate action.

5.  Relax NG Schema

   The Relax NG schema in [RFC5222] is modified to be:

   namespace a = ""
   default namespace ns1 = "urn:ietf:params:xml:ns:lost-plannedChange1"

   ##       Extension to Location-to-Service Translation (LoST) Protocol
   ##       to support a planned change to location data
   ##       plannedChange is used in the extensionPoint of
   ##       commonRequestPattern in a findService request
   ##       locationInvalidated is used by the LoST server to notify a
   ##       LIS that a previously valid location may be (or will become)
   ##       invalid
   ##       uriNotStored is a new warning to be used in a
   ##       exceptionContainer in the warnings element of a
   ##       findServiceResponse
   start =
     | locationInvalidated
     | uriNotStored
   ##       plannedChange
   div {
     plannedChange =
       element plannedChange {
         attribute uri {
           xsd:anyURI }?,
         attribute asOf {
           xsd:dateTime }?,

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   ##       locationInvalidated
   div {
     locationInvalidated =
       element locationInvalidated {
         attribute asOf {
           xsd:dateTime }?,

   ##       uriNotStored
   div {
     uriNotStored =
       element uriNotStored { basicException }

   ##       Patterns for inclusion of elements from schemas in
   ##       other namespaces.
   div {

     ##         Any element not in the LoST namespace.
     notLostChange = element * - (ns1:* | ns1:*) { anyElement }

     ##         A wildcard pattern for including any element
     ##         from any other namespace.
     anyElement =
       (element * { anyElement }
        | attribute * { text }
        | text)*

     ##         A point where future extensions
     ##         (elements from other namespaces)
     ##         can be added.

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     extensionPoint = notLostChanged*

6.  Security Considerations

   As an extension to LoST, this document inherits the security issues
   raised in [RFC5222].  The server could be tricked into storing a
   malicious URI which, when sent the locationInvalidated object could
   trigger something untoward.  The server MUST NOT accept any data from
   the client in response to POSTing the locationInvalidated.

   The server is subject to abuse by clients because it is being asked
   to store something and may need to send data to an uncontrolled URI.
   Clients could request many URIs for the same location for example.
   The server MUST have policy that limits use of this mechanism by a
   given client.  If the policy is exceeded, the server returns the
   uriNotStored warning.  The server MUST validate that the content of
   the uri sent is syntactically valid and meets the 256 byte limit.
   When sending the locationInvalidated object to the uri stored, the
   server MUST protect itself against common http vulnerabilities.

   The mutual authentication between client and server when is
   RECOMMENDED for both the initial findService operation that requests
   storing the uri and the sending of the locationInvalidated object.
   The server should be well known to the client, and its credential can
   be learned in a reliable way.  For example, a public safety system
   operating the LoST server may have a credential traceable to a well
   known Certificate Authority known to provide credentials for public
   safety agencies.  Many of the clients will be operated by local ISPs
   or other service providers where the server operator can reasonably
   obtain a good credential to use for the URI.  Where the server does
   not recognize the client, it's policy MAY limit the use of this
   feature beyond what it would limit a client it recognized.

7.  IANA Considerations

7.1.  Relax NG Schema Registration

      URI:  urn:ietf:params:xml:schema:lost-planedChange1

      Registrant Contact:  IETF ECRIT Working Group, Brian Rosen

      Relax NG Schema: The Relax NG schema to be registered is contained
         in Section 5.  Its first line is

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      default namespace = "urn:ietf:params:xml:ns:lost-PlannedChange1

      and its last line is


7.2.  LoST Namespace Registration

      URI:  urn:ietf:params:xml:ns:lost-plannedChange1

      Registrant Contact:  IETF ECRIT Working Group, Brian Rosen


   <?xml version="2.0"?>
   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN"
   <html xmlns="">
     <meta http-equiv="content-type"
     <title>LoST Planned Change Namespace</title>
     <h1>Namespace for LoST Planned Change extension</h1>
   <p>See <a href="">

8.  Normative References

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

   [RFC5222]  Hardie, T., Newton, A., Schulzrinne, H., and H.
              Tschofenig, "LoST: A Location-to-Service Translation
              Protocol", RFC 5222, August 2008.

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Author's Address

   Brian Rosen
   470 Conrad Dr
   Mars, PA  16046


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