draft-ietf-ecrit-location-hiding-req-01.txt   draft-ietf-ecrit-location-hiding-req-02.txt 
ECRIT H. Schulzrinne ECRIT H. Schulzrinne
Internet-Draft Columbia University Internet-Draft Columbia University
Intended status: Informational L. Liess Intended status: Informational L. Liess
Expires: April 15, 2009 Deutsche Telekom Expires: January 14, 2010 Deutsche Telekom
H. Tschofenig H. Tschofenig
Nokia Siemens Networks Nokia Siemens Networks
B. Stark B. Stark
AT&T AT&T
A. Kuett A. Kuett
Skype Skype
October 12, 2008 July 13, 2009
Location Hiding: Problem Statement and Requirements Location Hiding: Problem Statement and Requirements
draft-ietf-ecrit-location-hiding-req-01.txt draft-ietf-ecrit-location-hiding-req-02.txt
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Abstract Abstract
The emergency services architecture developed in the IETF Emergency The emergency services architecture developed in the IETF Emergency
Context Resolution with Internet Technology (ECRIT) working group Context Resolution with Internet Technology (ECRIT) working group
describes an architecture where location information is provided by describes an architecture where location information is provided by
access networks to end points or VoIP service providers in order to access networks to end points or VoIP service providers in order to
determine the correct dial string and information to route the call determine the correct dial string and information to route the call
to a Public Safety Answering Point (PSAP). For determining the PSAP to a Public Safety Answering Point (PSAP). For determining the PSAP
Uniform Resource Identifier (URI) the usage of the Location-to- Uniform Resource Identifier (URI) the usage of the Location-to-
Service Translation (LoST) Protocol is envisioned. Service Translation (LoST) Protocol is envisioned.
This document explores the architectural impact for the IETF This document provides a problem statement and lists requirements for
emergency services architecture for situations where the Internet situations where the Internet Access Provider (IAP) and/or the
Access Provider (IAP) and/or the Internet Service Provider (ISP) are Internet Service Provider (ISP) are only willing to disclose limited
only willing to disclose limited or no location information. or no location information.
This document provides a problem statement and lists requirements.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Emergency Services Architecture . . . . . . . . . . . . . 3 1.1. Emergency Services Architecture . . . . . . . . . . . . . . 4
1.2. Location Hiding . . . . . . . . . . . . . . . . . . . . . 3 1.2. Location Hiding . . . . . . . . . . . . . . . . . . . . . . 4
1.3. Location by Reference . . . . . . . . . . . . . . . . . . 4 1.3. Location by Reference . . . . . . . . . . . . . . . . . . . 5
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1. High-Level Requirements . . . . . . . . . . . . . . . . . 4 3.1. High-Level Requirements . . . . . . . . . . . . . . . . . . 6
3.2. Detailed Requirements . . . . . . . . . . . . . . . . . . 5 3.2. Detailed Requirements . . . . . . . . . . . . . . . . . . . 6
3.3. Desirable Properties . . . . . . . . . . . . . . . . . . . 6 3.3. Desirable Properties . . . . . . . . . . . . . . . . . . . 7
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 8
5. Security Considerations . . . . . . . . . . . . . . . . . . . 6 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 8
6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 7 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 8
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 8
7.1. Normative References . . . . . . . . . . . . . . . . . . . 7 7.1. Normative References . . . . . . . . . . . . . . . . . . . 8
7.2. Informative References . . . . . . . . . . . . . . . . . . 7 7.2. Informative References . . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 9
Intellectual Property and Copyright Statements . . . . . . . . . . 10
1. Introduction 1. Introduction
1.1. Emergency Services Architecture 1.1. Emergency Services Architecture
The emergency services architecture developed in the IETF Emergency The emergency services architecture developed in the IETF Emergency
Context Resolution with Internet Technology (ECRIT) working group, Context Resolution with Internet Technology (ECRIT) working group,
see [I-D.ietf-ecrit-framework], describes an architecture where see [I-D.ietf-ecrit-framework], describes an architecture where
location information is provided by access networks to end points or location information is provided by access networks to end points or
VoIP service providers in order to determine the correct dial string VoIP service providers in order to determine the correct dial string
skipping to change at page 3, line 28 skipping to change at page 4, line 28
geographical location together with a service URI [RFC5031]. The geographical location together with a service URI [RFC5031]. The
basic architecture is shown in Figure 1 of [I-D.ietf-ecrit-framework] basic architecture is shown in Figure 1 of [I-D.ietf-ecrit-framework]
and further detailed in the message flow in Figure 2 of and further detailed in the message flow in Figure 2 of
[I-D.ietf-ecrit-framework]. [I-D.ietf-ecrit-framework].
For emergency services, location information is needed in three ways: For emergency services, location information is needed in three ways:
1. Emergency call routing to the PSAP that is responsible for a 1. Emergency call routing to the PSAP that is responsible for a
specific geographical region specific geographical region
2. Dispatch of the emergency personnel to the scene of an accident, 2. Dispatch of the emergency personnel to the scene of an accident,
crime or other types of incidents crime or other types of incidents
3. Additionally, a VSP may need to verify that an call is indeed an 3. Additionally, a Voice Service Provider (VSP) may need to verify
emergency call and may therefore require location information to that an call is indeed an emergency call and may therefore
ensure that calls routed to a specific URI point to a PSAP. require location information to ensure that calls routed to a
specific URI point to a PSAP.
It is very important to note that this document only discusses This document focuses on item (1) and item (3). Providing location
location hiding in the context of location information that is need information by the ISP to the PSAP and to the emergency personnel are
for call routing. ISPs have no interest or even legal basis for typically legal obligations covered by regulatory frameworks.
hiding location information from emergency services personnel.
1.2. Location Hiding 1.2. Location Hiding
In some cases, location providers (e.g., Internet Access Providers Internet Access Providers (IAPs) and Internet Service Providers
(IAPs) and/or the Internet Service Providers (ISPs)) are unwilling to (ISPs)) typically have little incentives to provide location
provide precise location information to end points or VSPs, as is information to end hosts or independent VSPs (without monetary
called for in the above model. The decision to deny location can be compensation) for any purpose, including for emergency call routing.
driven by a number of technical and business concerns. Some The decision to deny disclosure of location information can be driven
providers may perceive a risk that allowing users to access location by a number of technical and business concerns. Some providers may
information for non-emergency purposes or prior to an emergency call perceive a risk that allowing users to access location information
will incur additional server load and thus costs. Other providers for non-emergency purposes or prior to an emergency call will incur
may not want to make location information available without the additional server load and thus costs. Other providers may not want
ability to charge for it. 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.
1.3. Location by Reference 1.3. Location by Reference
The work on the Location Configuration Protocol (LCP) indicated the The work on the Location Configuration Protocol (LCP) indicated the
need to provide the capability to obtain Location-by-References need to provide the capability to obtain Location-by-References
(LbyRs) in addition to Location-by-Value (LbyV) from a Location (LbyRs) in addition to Location-by-Value (LbyV) from a Location
Information Server (LIS). Information Server (LIS).
The LCP problem statement and requirements document can be found in The LCP problem statement and requirements document can be found in
[I-D.ietf-geopriv-l7-lcp-ps]. The requirements for obtaining an LbyR [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 via the LCP and the corresponding dereferencing step can be found in
[I-D.ietf-geopriv-lbyr-requirements]. [I-D.ietf-geopriv-lbyr-requirements].
HTTP Enabled Location Delivery (HELD), see HTTP Enabled Location Delivery (HELD), see
[I-D.ietf-geopriv-http-location-delivery], is an instantiation of the [I-D.ietf-geopriv-http-location-delivery], is an instantiation of the
LCP concept and allows LbyVs and LbyRs to be requested. LCP concept and allows LbyVs and LbyRs to be requested.
A location reference may already satisfy the requirement for location A location reference may already satisfy the requirement for location
hiding if the PSAP has the appropriate credentials to resolve the hiding if the PSAP has the appropriate credentials to resolve the
reference. This requires a trust relationship between the PSAP and reference. These credentials allow the ISP/IAP to authenticate and
the ISP. Note that the requirement being met here is for delivery of to authorize the party that would like to request location
location information to the PSAP, not for LoST routing or for information. The policy to obtain these credentials allows ISPs/IAPs
validation at the VSP. 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.
Unfortunately, a location reference is not compatible with LoST, as Note that the requirement being met here is for delivery of location
LoST requires an information value rather than a reference. Also, information to the PSAP, not for LoST routing or for validation at
LoST servers may be operated by the VSP, which may not have a trust the VSP. Another obstacle when it comes to the usage of location
relationship with the ISP. reference for location-based routing from a technical point of view
is that a location reference cannot be used as input to LoST
[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 [RFC5031].
2. Terminology 2. Terminology
The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119], with the document are to be interpreted as described in [RFC2119], with the
important qualification that, unless otherwise stated, these terms important qualification that, unless otherwise stated, these terms
apply to the design of an solution supporting location hiding, not apply to the design of an solution supporting location hiding, not
its implementation or application. its implementation or application.
This document reuses terminology from [I-D.ietf-geopriv-l7-lcp-ps]. This document reuses terminology from [I-D.ietf-geopriv-l7-lcp-ps].
3. Requirements 3. Requirements
3.1. High-Level Requirements 3.1. High-Level Requirements
Req-A: There MUST be a way an access network can withhold detailed
location information from any entity it wishes to, and Req-A: There MUST be a way for the ISP/IAP to withhold precise
specifically, the endpoint, and a VSP. location information from the endpoint and from the VSP.
Req-B: The ISP/IAP MUST support the ability of the endpoint or the Req-B: The ISP/IAP MUST support the ability of the endpoint or the
VSP to route emergency calls. VSP to route emergency calls.
Req-C: The VSP MUST be able to validate that a call purported to be Req-C: 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 an emergency call is being routed to a bona fide URI, which is
denoted by being a URI in LoST for the designated emergency denoted by being a URI in LoST for the designated emergency
service. service. This requirement is provided to deal with potential
security problems described in Section 5.1 of [RFC5069].
Req-D: The PSAP MUST be provided precise location information (by Req-D: The PSAP MUST receive precise location information (by value)
value) for emergency callers. The endpoint and/or VSP may provide about emergency callers. As such, any solution MUST be able to
this information either by value or by reference. provide location information to the PSAP even while withholding it
from the emergency caller.
3.2. Detailed Requirements 3.2. Detailed Requirements
Req-1: The proposed solution MUST NOT assume a business or trust Req-1: The proposed solution MUST NOT assume a business or trust
relationship between the caller's VSP and the caller's ISP. relationship between the caller's VSP and the caller's ISP.
Req-2: A solution MUST consider deployment scenarios where a VSP is Req-2: A solution MUST consider deployment scenarios where a VSP
outside the jurisdiction of the PSAP. does not operate in the same jurisdiction as the PSAP.
Req-3: The solution MUST offer automated discovery of servers and Req-3: The solution MUST offer automated discovery of servers and
other behavior, i.e., no manual configuration can be assumed. other behavior, i.e., no manual configuration can be assumed.
Req-4: The steps needed by the endpoint for emergency calling SHOULD Req-4: The steps needed by the endpoint for emergency calling SHOULD
be no different when location is withheld vs. when location is not be no different when location is withheld vs. when location is not
withheld. In particular, user agents cannot require additional withheld. In particular, user agents cannot require additional
configuration to discover which particular environment (hiding or configuration to discover which particular environment (hiding or
no hiding) they find themselves in. no hiding) they find themselves in.
Req-5: The solution SHOULD work for non-SIP entities, without the Req-5: The solution SHOULD work without the ISP/IAP having to
ISP/IAP having to support these protocols. support SIP and without the need to utilize SIP between the
endpoint and the VSP.
Req-6: The solution MUST work if PSAP boundaries have holes. Req-6: 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 [I-D.ietf-ecrit-specifying-holes].)
Req-7: The solution MUST NOT assume the existence of Emergency Req-7: The solution MUST NOT assume the existence of Emergency
Service Routing Proxies (ESRPs) per country, state and city. Service Routing Proxies (ESRPs) per country, state and city.
Req-8: The solution MUST consider that service boundaries for Req-8: The solution MUST consider that service boundaries for
different emergency services may differ, but they overlap at the different emergency services may differ, but they overlap at the
location of the caller. location of the caller.
Req-9: Though the solution MAY add steps to the emergency call Req-9: Though the solution MAY add steps to the emergency call
routing process described in [framework], these steps MUST NOT routing process described in [I-D.ietf-ecrit-framework], these
significantly increase call setup latency. For example, the steps MUST NOT significantly increase call setup latency. For
revised process MUST NOT include "trial-and-error" operations on example, the revised process MUST NOT include "trial-and-error"
its critical path, such as attempts at LbyR resolutions that may operations on its critical path, such as attempts at LbyR
take time to time out. resolutions that may take time to time out.
Req-10: The solution MUST allow the end host to determine PSAP/ESRP Req-10: The solution MUST allow the end host to determine PSAP/ESRP
URLs prior to the call, for all emergency services. URLs prior to the call, for all emergency services.
Req-11: The solution MUST allow UAs to discover at least their dial Req-11: The solution MUST allow UAs to discover at least their dial
string ahead of the emergency call. string ahead of the emergency call.
Req-12: The solution MUST have minimal impact on UAs. Req-12: 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.
Req-13: The solution MUST NOT interfere with the use of LoST for Req-13: The solution MUST NOT interfere with the use of LoST for
non-emergency services. non-emergency services.
Req-14: Deleted Req-14: The solution MUST allow emergency calls to reach an IP-to-
PSTN gateway rather than the IP-based PSAP directly.
Req-15: Calls may reach a PSTN gateway, rather than the PSAP
directly.
3.3. Desirable Properties 3.3. Desirable Properties
o The solution MUST NOT shift effort(externality), i.e., the o The solution MUST NOT shift effort(externality), i.e., the
convenience of the location-hiding ISP MUST NOT impose a burden on 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 user agents or non-hiding ISPs/IAPs and SHOULD NOT impose a burden
on VSPs. on VSPs.
o The solution SHOULD minimize the impact on LoST, SIP conveyance o The solution SHOULD minimize the impact on LoST, SIP conveyance
[I-D.ietf-sip-location-conveyance] and DHCP. [I-D.ietf-sip-location-conveyance] and DHCP.
o The solution SHOULD NOT rely on DHCP for LoST configuration, as o The solution SHOULD NOT break by the presence of NATs and SHOULD
the information in the DHCP server provided by the ISP may not consider the presence of legacy devices, as described in
reach the UA, due to NATs. [I-D.ietf-geopriv-l7-lcp-ps].
4. IANA Considerations 4. IANA Considerations
This document does not require actions by IANA. This document does not require actions by IANA.
5. Security Considerations 5. Security Considerations
This document does not raise additional security consideration beyond This document does not raise additional security consideration beyond
those mentioned in [I-D.ietf-geopriv-l7-lcp-ps] and discussed in this those mentioned in [I-D.ietf-geopriv-l7-lcp-ps] and discussed in this
document. document.
skipping to change at page 7, line 18 skipping to change at page 8, line 34
We would like to thank the following ECRIT working group members (in We would like to thank the following ECRIT working group members (in
no particular order) for their contributions: no particular order) for their contributions:
o Andrew Newton (andy@hxr.us) o Andrew Newton (andy@hxr.us)
o James Winterbottom (James.Winterbottom@andrew.com) o James Winterbottom (James.Winterbottom@andrew.com)
o Brian Rosen (br@brianrosen.net) o Brian Rosen (br@brianrosen.net)
o Richard Barnes (rbarnes@bbn.com) o Richard Barnes (rbarnes@bbn.com)
o Marc Linsner (mlinsner@cisco.com) o Marc Linsner (mlinsner@cisco.com)
o Ted Hardie (hardie@qualcomm.com) o Ted Hardie (hardie@qualcomm.com)
The authors would also like to thank Ben Campbell for his Gen-ART
review.
7. References 7. References
7.1. Normative References 7.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", March 1997. Requirement Levels", March 1997.
7.2. Informative References 7.2. Informative References
[I-D.ietf-geopriv-l7-lcp-ps] [I-D.ietf-geopriv-l7-lcp-ps]
Tschofenig, H. and H. Schulzrinne, "GEOPRIV Layer 7 Tschofenig, H. and H. Schulzrinne, "GEOPRIV Layer 7
Location Configuration Protocol; Problem Statement and Location Configuration Protocol; Problem Statement and
Requirements", draft-ietf-geopriv-l7-lcp-ps-08 (work in Requirements", draft-ietf-geopriv-l7-lcp-ps-09 (work in
progress), June 2008. progress), February 2009.
[I-D.ietf-sip-location-conveyance] [I-D.ietf-sip-location-conveyance]
Polk, J. and B. Rosen, "Location Conveyance for the Polk, J. and B. Rosen, "Location Conveyance for the
Session Initiation Protocol", Session Initiation Protocol",
draft-ietf-sip-location-conveyance-10 (work in progress), draft-ietf-sip-location-conveyance-13 (work in progress),
September 2008. March 2009.
[I-D.ietf-ecrit-framework] [I-D.ietf-ecrit-framework]
Rosen, B., Schulzrinne, H., Polk, J., and A. Newton, Rosen, B., Schulzrinne, H., Polk, J., and A. Newton,
"Framework for Emergency Calling using Internet "Framework for Emergency Calling using Internet
Multimedia", draft-ietf-ecrit-framework-06 (work in Multimedia", draft-ietf-ecrit-framework-09 (work in
progress), July 2008. progress), March 2009.
[RFC5069] Taylor, T., Tschofenig, H., Schulzrinne, H., and M.
Shanmugam, "Security Threats and Requirements for
Emergency Call Marking and Mapping", RFC 5069,
January 2008.
[RFC5222] Hardie, T., Newton, A., Schulzrinne, H., and H. [RFC5222] Hardie, T., Newton, A., Schulzrinne, H., and H.
Tschofenig, "LoST: A Location-to-Service Translation Tschofenig, "LoST: A Location-to-Service Translation
Protocol", RFC 5222, August 2008. Protocol", RFC 5222, August 2008.
[I-D.ietf-geopriv-lbyr-requirements] [I-D.ietf-geopriv-lbyr-requirements]
Marshall, R., "Requirements for a Location-by-Reference Marshall, R., "Requirements for a Location-by-Reference
Mechanism", draft-ietf-geopriv-lbyr-requirements-03 (work Mechanism", draft-ietf-geopriv-lbyr-requirements-07 (work
in progress), July 2008. in progress), February 2009.
[RFC5031] Schulzrinne, H., "A Uniform Resource Name (URN) for [RFC5031] Schulzrinne, H., "A Uniform Resource Name (URN) for
Emergency and Other Well-Known Services", RFC 5031, Emergency and Other Well-Known Services", RFC 5031,
January 2008. January 2008.
[I-D.ietf-geopriv-http-location-delivery] [I-D.ietf-geopriv-http-location-delivery]
Barnes, M., Winterbottom, J., Thomson, M., and B. Stark, Barnes, M., Winterbottom, J., Thomson, M., and B. Stark,
"HTTP Enabled Location Delivery (HELD)", "HTTP Enabled Location Delivery (HELD)",
draft-ietf-geopriv-http-location-delivery-09 (work in draft-ietf-geopriv-http-location-delivery-15 (work in
progress), September 2008. progress), June 2009.
[I-D.ietf-ecrit-specifying-holes]
Winterbottom, J. and M. Thomson, "Specifying Holes in LoST
Service Boundaries", draft-ietf-ecrit-specifying-holes-01
(work in progress), October 2008.
Authors' Addresses Authors' Addresses
Henning Schulzrinne Henning Schulzrinne
Columbia University Columbia University
Department of Computer Science Department of Computer Science
450 Computer Science Building 450 Computer Science Building
New York, NY 10027 New York, NY 10027
US US
skipping to change at page 8, line 38 skipping to change at page 10, line 25
Email: hgs+ecrit@cs.columbia.edu Email: hgs+ecrit@cs.columbia.edu
URI: http://www.cs.columbia.edu URI: http://www.cs.columbia.edu
Laura Liess Laura Liess
Deutsche Telekom Networks Deutsche Telekom Networks
Deutsche Telekom Allee 7 Deutsche Telekom Allee 7
Darmstadt, Hessen 64295 Darmstadt, Hessen 64295
Germany Germany
Phone: Phone:
Email: Laura.Liess@t-systems.com Email: L.Liess@telekom.de
URI: http://www.telekom.de URI: http://www.telekom.de
Hannes Tschofenig Hannes Tschofenig
Nokia Siemens Networks Nokia Siemens Networks
Linnoitustie 6 Linnoitustie 6
Espoo 02600 Espoo 02600
Finland Finland
Phone: +358 (50) 4871445 Phone: +358 (50) 4871445
Email: Hannes.Tschofenig@gmx.net Email: Hannes.Tschofenig@gmx.net
URI: http://www.tschofenig.priv.at URI: http://www.tschofenig.priv.at
skipping to change at page 9, line 22 skipping to change at page 11, line 4
URI: http://www.tschofenig.priv.at URI: http://www.tschofenig.priv.at
Barbara Stark Barbara Stark
AT&T AT&T
725 W Peachtree St, NE 725 W Peachtree St, NE
Atlanta, GA 30308 Atlanta, GA 30308
USA USA
Phone: +1 404 499 7026 Phone: +1 404 499 7026
Email: barbara.stark@att.com Email: barbara.stark@att.com
Andres Kuett Andres Kuett
Skype Skype
Email: andres.kytt@skype.net Email: andres.kytt@skype.net
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
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