One document matched: draft-ietf-ecrit-location-hiding-req-04.xml


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<rfc category="info" ipr="pre5378Trust200902" docName="draft-ietf-ecrit-location-hiding-req-04.txt">
  <front>
    <title abbrev="Location Hiding Requirements">Location Hiding: Problem Statement and Requirements</title>

    <author initials="H." surname="Schulzrinne" fullname="Henning Schulzrinne">
      <organization>Columbia University</organization>
      <address>
        <postal>
          <street>Department of Computer Science</street>
          <street>450 Computer Science Building</street>
          <city>New York</city>
          <region>NY</region>
          <code>10027</code>
          <country>US</country>
        </postal>
        <phone>+1 212 939 7004</phone>
        <email>hgs+ecrit@cs.columbia.edu</email>
        <uri>http://www.cs.columbia.edu</uri>
      </address>
    </author>
    <author initials="L." surname="Liess" fullname="Laura Liess">
      <organization abbrev="Deutsche Telekom">Deutsche Telekom Networks</organization>
      <address>
        <postal>
          <street>Deutsche Telekom Allee 7</street>
          <city>Darmstadt</city>
          <region>Hessen</region>
          <code>64295</code>
          <country>Germany</country>
        </postal>
        <phone> </phone>
        <email>L.Liess@telekom.de</email>
        <uri>http://www.telekom.de</uri>
      </address>
    </author>
    <author initials="H." surname="Tschofenig" fullname="Hannes Tschofenig">
      <organization>Nokia Siemens Networks</organization>
      <address>
        <postal>
          <street>Linnoitustie 6</street>
          <city>Espoo</city>
          <code>02600</code>
          <country>Finland</country>
        </postal>
        <phone>+358 (50) 4871445</phone>
        <email>Hannes.Tschofenig@gmx.net</email>
        <uri>http://www.tschofenig.priv.at</uri>
      </address>
    </author>
    <author initials="B." surname="Stark" fullname="Barbara Stark">
      <organization>AT&T</organization>
      <address>
        <postal>
          <street>725 W Peachtree St, NE</street>
          <city>Atlanta</city>
          <region>GA</region>
          <code>30308</code>
          <country>USA</country>
        </postal>
        <phone>+1 404 499 7026</phone>
        <email>barbara.stark@att.com</email>
      </address>
    </author>
    <author initials="A." surname="Kuett" fullname="Andres Kuett">
      <organization>Skype</organization>
      <address>
        <postal>
          <street/>
          <city/>
          <region/>
          <code/>
          <country/>
        </postal>
        <email>andres.kytt@skype.net</email>
      </address>
    </author>
    <date year="2010"/>
    <area>Real-time Applications and Infrastructure</area>
    <workgroup>ECRIT</workgroup>
    <keyword>Internet-Draft</keyword>
    <abstract>
      <t>The emergency services architecture developed in the IETF Emergency Context Resolution with
        Internet Technology (ECRIT) working group describes an architecture where location
        information is provided by access networks to end points or VoIP service providers in order
        to determine the correct dial string and information to route the call to a Public Safety
        Answering Point (PSAP). For determining the PSAP Uniform Resource Identifier (URI) the usage
        of the Location-to-Service Translation (LoST) Protocol is envisioned. </t>

      <t>This document provides a problem statement and lists requirements for situations where the
        Internet Access Provider (IAP) and/or the Internet Service Provider (ISP) are only willing
        to disclose limited or no location information.</t>

    </abstract>
  </front>
  <middle>

    <!-- ////////////////////////////////////////////////////////////////////////////////// -->
    <section anchor="introduction" title="Introduction">

      <section title="Emergency Services Architecture">

        <t>The emergency services architecture developed in the IETF Emergency Context Resolution
          with Internet Technology (ECRIT) working group, see <xref
            target="I-D.ietf-ecrit-framework"/>, describes an architecture where location
          information is provided by access networks to end points or VoIP service providers in
          order to determine the correct dial string and information to route the call to a Public
          Safety Answering Point (PSAP). The Location-to-Service Translation (LoST) Protocol <xref
            target="RFC5222"/> allows callers and other call-routing entities to determine the PSAP
          Uniform Resource Identifier (URI) for a specific geographical location together with a
          service URI <xref target="RFC5031"/>. The basic architecture is shown in Figure 1 of <xref
            target="I-D.ietf-ecrit-framework"/> and further detailed in the message flow in Figure 2
          of <xref target="I-D.ietf-ecrit-framework"/>. </t>

        <t>For emergency services, location information is needed in three ways: <list
            style="numbers">
            <t>Emergency call routing to the PSAP that is responsible for a specific geographical
              region</t>
            <t>Dispatch of the emergency personnel to the scene of an accident, crime or other types
              of incidents</t>
            <t>Additionally, a Voice Service Provider (VSP) may need to verify that an call is
              indeed an emergency call and may therefore require location information to ensure that
              calls routed to a specific URI point to a PSAP.</t>
          </list>
        </t>
        <t>This document focuses on item (1) and item (3). Providing location information by the ISP
          to the PSAP and to the emergency personnel are typically legal obligations covered by
          regulatory frameworks.</t>
      </section>


      <section title="Location Hiding">

        <t>Internet Access Providers (IAPs) and Internet Service Providers (ISPs)) typically have
          little incentives to provide location information to end hosts or independent VSPs
          (without monetary compensation) for any purpose, including for emergency call routing. The
          decision to deny disclosure of location information can be driven by a number of technical
          and business concerns. Some providers may perceive a risk that allowing users to access
          location information for non-emergency purposes or prior to an emergency call will incur
          additional server load and thus costs. Other providers may not want to make location
          information available without the ability to charge for it. Yet others fear problems with
          regard to privacy when disclosing location information to potentially unknown third
          parties.</t>

      </section>

      <section title="Location by Reference">

        <t>The work on the Location Configuration Protocol (LCP) indicated the need to provide the
          capability to obtain Location-by-References (LbyRs) in addition to Location-by-Value
          (LbyV) from a Location Information Server (LIS).</t>

        <t> The LCP problem statement and requirements document can be found in <xref
            target="I-D.ietf-geopriv-l7-lcp-ps"/>. The requirements for obtaining an LbyR via the
          LCP and the corresponding dereferencing step can be found in <xref
            target="I-D.ietf-geopriv-lbyr-requirements"/>. </t>

        <t>HTTP Enabled Location Delivery (HELD), see <xref
            target="I-D.ietf-geopriv-http-location-delivery"/>, is an instantiation of the LCP
          concept and allows LbyVs and LbyRs to be requested. </t>

        <t>A location reference may already satisfy the requirement for location hiding if the PSAP
          has the appropriate credentials to resolve the reference. These credentials allow the
          ISP/IAP to authenticate and to authorize the party that would like to request location
          information. The policy to obtain these credentials allows ISPs/IAPs to put constraints
          under which these credentials are handed out. ISP/IAPs ideally might want to engage in a
          business relationship with the VSP to receive a financial compensation for the service
          they provide. On the Internet the number of VSPs is potentially large and the VSPs would
          not want to enter a business contract with potentially every ISP/IAP worldwide. The number
          of potential contracts between ISPs/IAPs and PSAPs is, however, relatively small as they
          typically need to have a local relationship as PSAPs provide their emergency services
          support in a certain geographical region for which certain ISPs/IAPs have networks
          deployed. </t>

        <t>Note that the requirement being met here is for delivery of location information to the
          PSAP, not for LoST routing or for validation at the VSP. Another obstacle when it comes to
          the usage of location reference for location-based routing from a technical point of view
          is that a location reference cannot be used as input to LoST <xref target="RFC5222"/>, as
          LoST requires location per value rather than a reference. Also, LoST servers may be
          operated by independent parties, including VSPs, which again may not be able to resolve
          the reference to location by value. (Note that LoST is a protocol used for determining the
          location-appropriate PSAP based on location information and a Service URN <xref
            target="RFC5031"/>.</t>
      </section>

    </section>

    <!-- ////////////////////////////////////////////////////////////////////////////////// -->

    <section anchor="terminology" title="Terminology">

      <t>The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT",
        "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in
          <xref target="RFC2119"/>, with the important qualification that, unless otherwise stated,
        these terms apply to the design of an solution supporting location hiding, not its
        implementation or application.</t>

      <t>This document reuses terminology from <xref target="I-D.ietf-geopriv-l7-lcp-ps"/>. </t>

    </section>

    <!-- ////////////////////////////////////////////////////////////////////////////////// -->

    <section anchor="reqs" title="Requirements">
        <t>
          <list style="hanging">
            <t hangText="Req-1:"> There MUST be a way for the ISP/IAP to withhold precise location
              information from the endpoint and from the VSP.<vspace blankLines="1"/></t>
            <t hangText="Req-2:"> The ISP/IAP MUST support the ability of the endpoint or the VSP to
              route emergency calls. <vspace blankLines="1"/></t>
            <t hangText="Req-3:">The VSP MUST be able to validate that a call purported to be an
              emergency call is being routed to a bona fide URI, which is denoted by being a URI in
              LoST for the designated emergency service. This requirement is provided to deal with
              potential security problems described in Section 5.1 of <xref target="RFC5069"
                />.<vspace blankLines="1"/></t>
            <t hangText="Req-4:"> The PSAP MUST receive precise location information (by value)
              about emergency callers. As such, any solution MUST be able to provide location
              information to the PSAP even while withholding it from the emergency caller.</t>
            <t hangText="Req-5:"> The proposed solution MUST NOT assume a business or trust
              relationship between the caller's VSP and the caller's ISP. <vspace blankLines="1"/></t>
            <t hangText="Req-6:"> A solution MUST consider deployment scenarios where a VSP does not
              operate in the same jurisdiction as the PSAP. <vspace blankLines="1"/></t>
            <t hangText="Req-7:"> The solution MUST offer automated discovery of servers and and other
necessary configuration information. No manual configuration can be assumed. <vspace blankLines="1"/></t>
            <t hangText="Req-8:">The steps needed by the endpoint for emergency calling SHOULD be no
              different when location is withheld vs. when location is not withheld. In particular,
              user agents cannot require additional configuration to discover which particular
              environment (hiding or no hiding) they find themselves in. <vspace blankLines="1"/></t>
            <t hangText="Req-9:">The solution SHOULD work without the ISP/IAP having to support SIP
              and without the need to utilize SIP between the endpoint and the VSP. <vspace
                blankLines="1"/></t>
            <t hangText="Req-10:">The solution MUST work if PSAP boundaries have holes. (For a
              discussion about holes in PSAP boundaries and their encoding the reader is referred to
                <xref target="I-D.ietf-ecrit-specifying-holes"/>.)<vspace blankLines="1"/></t>
            <t hangText="Req-11:">The solution MUST NOT assume the existence of Emergency Service
              Routing Proxies (ESRPs) per country, state and city. <vspace blankLines="1"/></t>
            <t hangText="Req-12:">The solution MUST consider that service boundaries for different
              emergency services may differ, but they overlap at the location of the caller.<vspace
                blankLines="1"/></t>
            <t hangText="Req-13:"> Though the solution MAY add steps to the emergency call routing
              process described in <xref target="I-D.ietf-ecrit-framework"/>, these steps MUST NOT
              significantly increase call setup latency. For example, the revised process MUST NOT
              include "trial-and-error" operations on its critical path, such as attempts at LbyR
              resolutions that may take time to time out. <vspace blankLines="1"/></t>
            <t hangText="Req-14:">The solution MUST allow the end host to determine PSAP/ESRP URLs
              prior to the call, for all emergency services. <vspace blankLines="1"/></t>
            <t hangText="Req-15:">The solution MUST allow UAs to discover at least their dial string
              ahead of the emergency call. <vspace blankLines="1"/></t>
            <t hangText="Req-16:">The solution MUST have minimal impact on UAs, i.e., a solution is
              preferred if it does not require an substantially different emergency services
              procedures compared to the procedure of dealing with emergency services where no
              location hiding is applied. <vspace blankLines="1"/></t>
            <t hangText="Req-17:">The solution MUST NOT interfere with the use of LoST for
              non-emergency services. <vspace blankLines="1"/></t>
            <t hangText="Req-18:">The solution MUST allow emergency calls to reach an IP-to-PSTN
              gateway rather than the IP-based PSAP directly. <vspace blankLines="1"/></t>
            <t hangText="Req-19:">The solution MUST NOT shift effort (externality), i.e., the
              convenience of the location-hiding ISP MUST NOT impose a burden on user agents or
              non-hiding ISPs/IAPs and SHOULD NOT impose a burden on VSPs.<vspace blankLines="1"/></t>
            <t hangText="Req-20:">The solution SHOULD minimize the impact on LoST, SIP conveyance
                <xref target="I-D.ietf-sipcore-location-conveyance"/> and DHCP.<vspace blankLines="1"/></t>
            <t hangText="Req-21:">The solution SHOULD NOT break in the presence of NATs and SHOULD
              consider the presence of legacy devices, as described in <xref
                target="I-D.ietf-geopriv-l7-lcp-ps"/>.</t>
          </list>
        </t>

    </section>

    <!-- ////////////////////////////////////////////////////////////////////////////////// -->

    <section title="IANA Considerations">
      <t>This document does not require actions by IANA.</t>
    </section>

    <!-- ////////////////////////////////////////////////////////////////////////////////// -->

    <section title="Security Considerations">
      <t>This document does not raise additional security consideration beyond those mentioned in
          <xref target="I-D.ietf-geopriv-l7-lcp-ps"/> and discussed in this document.</t>
    </section>

    <!-- ////////////////////////////////////////////////////////////////////////////////// -->

    <section title="Acknowledgments">
      <t>We would like to thank the following ECRIT working group members (in no particular order)
        for their contributions:</t>
      <t>
        <list style="symbols">
          <t>Andrew Newton (andy@hxr.us) </t>
          <t>James Winterbottom (James.Winterbottom@andrew.com) </t>
          <t>Brian Rosen (br@brianrosen.net) </t>
          <t>Richard Barnes (rbarnes@bbn.com)</t>
          <t>Marc Linsner (mlinsner@cisco.com)</t>
          <t>Ted Hardie (hardie@qualcomm.com)</t>
        </list>
      </t>
      <t>The authors would also like to thank Ben Campbell for his Gen-ART review. Additionally, we would like to thank Jari Arkko, Alexey Melnikov, Tim Polk, and Dan Romascanu for their IESG review.</t>
    </section>

    <!-- ////////////////////////////////////////////////////////////////////////////////// -->

  </middle>

  <!-- ////////////////////////////////////////////////////////////////////////////////// -->

  <back>
    <references title="Normative References">
      <reference anchor="RFC2119">
        <front>
          <title abbrev="RFC Key Words">Key words for use in RFCs to Indicate Requirement Levels</title>
          <author initials="S." surname="Bradner" fullname="Scott Bradner">
            <organization>Harvard University</organization>
          </author>
          <date month="March" year="1997"/>
        </front>
        <format type="TXT" octets="4723" target="ftp://ftp.isi.edu/in-notes/rfc2119.txt"/>
      </reference>
	  &I-D.ietf-geopriv-l7-lcp-ps;
      &I-D.ietf-sipcore-location-conveyance; 
	  &I-D.ietf-ecrit-framework; 
	  &RFC5069;
      &RFC5222; 
	  &I-D.ietf-geopriv-lbyr-requirements; 
	  &RFC5031;
      &I-D.ietf-geopriv-http-location-delivery; 
	  &I-D.ietf-ecrit-specifying-holes;
    </references>

    <references title="Informative References"> 
    </references>
  </back>

</rfc>

PAFTECH AB 2003-20262026-04-22 06:48:29