draft-ietf-ecrit-held-routing-02.txt   draft-ietf-ecrit-held-routing-03.txt 
ECRIT J. Winterbottom ECRIT J. Winterbottom
Internet-Draft Winterb Consulting Services Internet-Draft Winterb Consulting Services
Updates: RFC6881, RFC5985 H. Tschofenig Updates: RFC6881, RFC5985 (if approved) H. Tschofenig
(if approved) Intended status: Standards Track
Intended status: Standards Track L. Liess Expires: January 21, 2016 L. Liess
Expires: October 7, 2015 Deutsche Telekom Deutsche Telekom
April 5, 2015 July 20, 2015
A Routing Request Extension for the HELD Protocol A Routing Request Extension for the HELD Protocol
draft-ietf-ecrit-held-routing-02.txt draft-ietf-ecrit-held-routing-03.txt
Abstract Abstract
In many circumstances public LoST servers or a distributed network of For cases where location servers have access to emergency routing
forest guides linking public LoST servers is not available. The information they are able to return routing information with the
general ECRIT calling models breakdown without publically accessible location information if the location request includes a request for
LoST servers. Sometimes location servers may have access to the desired routing information. This document specifies an
emergency routing information. This document defines an extension to extension to the HELD protocol to support this funciton.
the HELD protocol so a location request can include a request for
routing information and allowing the subsequent location response to
include routing information.
Status of this Memo Status of This Memo
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provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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Copyright Notice Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the Copyright (c) 2015 IETF Trust and the persons identified as the
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.1. LoST Reuse Considerations . . . . . . . . . . . . . . . . 6
5. HELD Schema Extension . . . . . . . . . . . . . . . . . . . . 8 4. Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . 6
6. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 5. HELD Schema Extension . . . . . . . . . . . . . . . . . . . . 7
7. Privacy Considerations . . . . . . . . . . . . . . . . . . . . 10 6. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 9
8. Security Considerations . . . . . . . . . . . . . . . . . . . 10 7. Privacy Considerations . . . . . . . . . . . . . . . . . . . 10
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 8. Security Considerations . . . . . . . . . . . . . . . . . . . 11
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
9.1. URN sub-namespace registration for 9.1. URN sub-namespace registration for
'urn:ietf:params:xml:ns:geopriv:held:ri' . . . . . . . . . 10 'urn:ietf:params:xml:ns:geopriv:held:ri' . . . . . . . . 11
9.2. XML Schema Registration . . . . . . . . . . . . . . . . . 11 9.2. XML Schema Registration . . . . . . . . . . . . . . . . . 11
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 11 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12
11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
11.1. Normative References . . . . . . . . . . . . . . . . . . . 12 11.1. Normative References . . . . . . . . . . . . . . . . . . 12
11.2. Informative References . . . . . . . . . . . . . . . . . . 12 11.2. Informative References . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 13 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13
1. Introduction 1. Introduction
The general ECRIT calling models described in [RFC6443] and The general ECRIT calling models described in [RFC6443] and
[RFC6881]require a local LoST server or network of forest guides in [RFC6881]require a local LoST server or network of forest guides in
order to determine the address of the PSAP in the best position to order to determine the address of the PSAP in the best position to
handle a call. Networks of forest guides have not eventuated and handle a call. Networks of forest guides have not eventuated and
while PSAPs are moving towards IP networks, LoST server deployment is while PSAPs are moving towards IP networks, LoST server deployment is
not ubiquitous. Some regions and countries have expressed reluctance not ubiquitous. Some regions and countries have expressed reluctance
to deploy LoST servers making aspects of the current ECRIT to deploy LoST servers making aspects of the current ECRIT
skipping to change at page 4, line 32 skipping to change at page 4, line 22
+------^-+ (3) | +--------+ +------^-+ (3) | +--------+
| | +--------V----+ ^ | | +--------V----+ ^
| +-----Service----| LoST Server | | | +-----Service----| LoST Server | |
| (4) +-------------+ +---+---+ | (4) +-------------+ +---+---+
+-------------Call Initiation------------>| VSP | +-------------Call Initiation------------>| VSP |
(5) +-------+ (5) +-------+
Figure 1: Device-Centric Emergency Services Model Figure 1: Device-Centric Emergency Services Model
The second approach is a softswitch-centric model, where a device The second approach is a softswitch-centric model, where a device
initiates and emergency call and the serving softswitch detects that initiates an emergency call and the serving softswitch detects that
the call is an emergency and initiates retrieving the caller's the call is an emergency and initiates retrieving the caller's
location from a Location Information Server (LIS) using HELD location from a Location Information Server (LIS) using HELD
[RFC5985] with identity extensions [RFC6155] [RFC6915] and then [RFC5985] with identity extensions [RFC6155] [RFC6915] and then
determining the route to the local PSAP using LoST [RFC5222]. determining the route to the local PSAP using LoST [RFC5222].
Figure 2 shows the high-level protocol interactions. Figure 2 shows the high-level protocol interactions.
+---Location Request---+ +---Location Request---+
| (2) | | (2) |
+---V---+ | +---V---+ |
| LIS | | | LIS | |
skipping to change at page 6, line 27 skipping to change at page 6, line 5
information. information.
This document specifies an extension to the HELD protocol so that This document specifies an extension to the HELD protocol so that
emergency routing information can be requested from the LIS at the emergency routing information can be requested from the LIS at the
same time that location information is requested. The document same time that location information is requested. The document
updates [RFC6881] by requiring devices and softswitches that updates [RFC6881] by requiring devices and softswitches that
understand this specification to always request routing information understand this specification to always request routing information
to avoid the risk of query failure where no LoST server or forest to avoid the risk of query failure where no LoST server or forest
guide network is deployed. guide network is deployed.
3.1. LoST Reuse Considerations
The LoST Protocol [RFC5222] defines a <mapping> element that
describes a service region and associated service URLs. Reusing this
element from LoST to provide the routing URIs was considered.
However, this would have meant that several of the mandatory
components in the <mapping> element would have had to contain
ambiguous or misleading values. Specifically, the "source" attribute
is required to contain a LoST application unique string for the
authoritative server. However, in the situations described in this
specification there may not be an authoritative LoST server, so any
value put into this attribute would be misleading. In addition to
this, routing information received in the manner described in this
specification should not be cached by the receiver, so detailing when
the routing information expires or was last updated is irrelevant.
4. Mechanism 4. Mechanism
The mechanism consists of adding an element to the HELD The mechanism consists of adding an element to the HELD
locationRequest and an element to the locationResponse. locationRequest and an element to the locationResponse.
The request element indicates that the requestor wants the LIS to The request element indicates that the requestor wants the LIS to
provide routing information based on the location of the end-device. provide routing information based on the location of the end-device.
If the routing request is sent with no attribute then URIs for If the routing request is sent with no attribute then URIs for
urn:service:sos are returned. If the requestor wants routing urn:service:sos are returned. If the requestor wants routing
information for a specific service then they may include an optional information for a specific service then they may include an optional
skipping to change at page 6, line 51 skipping to change at page 6, line 45
If the LIS understands the routing request and has routing If the LIS understands the routing request and has routing
information for the location then it includes the information in a information for the location then it includes the information in a
routingInformation element returned in the locationResponse. How the routingInformation element returned in the locationResponse. How the
LIS obtains this information is left to implementation, one possible LIS obtains this information is left to implementation, one possible
option is that the LIS acquires it from a LoST server, other option is that the LIS acquires it from a LoST server, other
possibilities are described in Section 3. possibilities are described in Section 3.
A LIS that does not understand the routing request element ignores it A LIS that does not understand the routing request element ignores it
and returns location as normal. and returns location as normal.
A LIS that does support the routing request element SHALL support A LIS that does support the routing request element MUST support
returning URIs for urn:service:sos returning URIs for urn:service:sos and any regionally defined sub-
services while following the URN traversal rules defined in
[RFC5031].
A LIS that does understand the routing request element but can't A LIS that does understand the routing request element but can't
obtain any routing information for the end-device's location SHALL obtain any routing information for the end-device's location MUST
only return location information. only return location information.
A LIS that understands the routing request element but not the A LIS that understands the routing request element but not the
specified service URN, returns the routing URIs for the specified service URN, MUST follow the URN traversal rules defined in
urn:service:sos service. [RFC5031].
A LIS that receives a request for emergency routing information that
it understands MUST return the correct emergency routing information
if it has or is able to acquire the routing information for the
location of the target device.
The routing information in the location response consists of a The routing information in the location response consists of a
service element identified by a service name. The service name is a service element identified by a service name. The service name is a
urn and might contain a general emergency service urn such as urn and might contain a general emergency service urn such as
urn:service:sos or might contain a specific service urn depending on urn:service:sos or might contain a specific service urn depending on
what was requested and what the LIS is able to provide. A list of what was requested and what the LIS is able to provide. A list of
one or more service destinations is provided for the service name. one or more service destinations is provided for the service name.
Each destination is expressed as a URI and each URI scheme should Each destination is expressed as a URI and each URI scheme should
only appear once in this list. The routing URIs are intended to be only appear once in this list. The routing URIs are intended to be
used at the time they are received. To avoid any risks of using used at the time they are received. To avoid any risks of using
stale routing URIs the values MUST NOT be cached by the receiving stale routing URIs the values MUST NOT be cached by the receiving
entity. entity.
The LoST Protocol [RFC5222] defines a <mapping> element that
describes a service region and associated service URLs. Reusing this
element from LoST to provide the routing URIs was considered.
However, this would have meant that several of the mandatory
components in the <mapping> element would have had to contain
ambiguous or misleading values. Specifically, the "source" attribute
is required to contain a LoST application unique string for the
authoritative server. However, in the situations described in this
specification there may not be an authoritative LoST server, so any
value put into this attribute would be misleading. In addition to
this, routing information received in the manner described in this
specification should not be cached by the receiver, so detailing when
the routing information expires or was last updated is irrelevant.
5. HELD Schema Extension 5. HELD Schema Extension
This section describes the schema extension to HELD. This section describes the schema extension to HELD.
<?xml version="1.0"?> <?xml version="1.0"?>
<xs:schema <xs:schema
targetNamespace="urn:ietf:params:xml:ns:geopriv:held:ri" targetNamespace="urn:ietf:params:xml:ns:geopriv:held:ri"
xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:ri="urn:ietf:params:xml:ns:geopriv:held:ri" xmlns:ri="urn:ietf:params:xml:ns:geopriv:held:ri"
xmlns:xml="http://www.w3.org/XML/1998/namespace" xmlns:xml="http://www.w3.org/XML/1998/namespace"
skipping to change at page 10, line 35 skipping to change at page 10, line 35
</service> </service>
</routingInformation> </routingInformation>
</locationResponse> </locationResponse>
Figure 4: Example Location Response Figure 4: Example Location Response
7. Privacy Considerations 7. Privacy Considerations
This document makes no changes that require privacy considerations This document makes no changes that require privacy considerations
beyond those already described in [RFC5985] and [RFC6155]. beyond those already described in [RFC5687]. It does however extend
those described in [RFC6155].
[RFC5687] describes the issues surrounding Layer 7 location
configuration protocols, which this document makes no specific
changes to.
[RFC6155] extends HELD beyond a simple LCP by enabling authorized
third-parties to acquire location information and describes the
issues in Section 4. The HELD Routing extension supports returning
URIs that represent specific services operating in the Target's
vicinity. This represents additional information about the Target,
as a consequence it is recommended that this option only be used when
a location URI is returned by the LIS.
8. Security Considerations 8. Security Considerations
This document imposes no additional security considerations beyond This document imposes no additional security considerations beyond
those already described in [RFC5985] and [RFC6155]. those already described in [RFC5687] and [RFC6155].
9. IANA Considerations 9. IANA Considerations
9.1. URN sub-namespace registration for 9.1. URN sub-namespace registration for
'urn:ietf:params:xml:ns:geopriv:held:ri' 'urn:ietf:params:xml:ns:geopriv:held:ri'
This document calls for IANA to register a new XML namespace, as per This document calls for IANA to register a new XML namespace, as per
the guidelines in [RFC3688]. the guidelines in [RFC3688].
URI: urn:ietf:params:xml:ns:geopriv:held:ri URI: urn:ietf:params:xml:ns:geopriv:held:ri
skipping to change at page 11, line 47 skipping to change at page 12, line 12
Registrant Contact: IETF, ECRIT working group, (ecrit@ietf.org), Registrant Contact: IETF, ECRIT working group, (ecrit@ietf.org),
James Winterbottom (a.james.winterbottom@gmail.com). James Winterbottom (a.james.winterbottom@gmail.com).
The XML for this schema can be found as the entirety of Section 5 The XML for this schema can be found as the entirety of Section 5
of this document. of this document.
10. Acknowledgements 10. Acknowledgements
We would like to thank Wilfried Lange for sharing his views with us. We would like to thank Wilfried Lange for sharing his views with us.
We would also like to thank Bruno Chatras for his early review We would also like to thank Bruno Chatras for his early review
comments and Bernd Henschel for his support. Thanks to Roger comments and Keith Drage ofr his more detailed review. Thanks to
Marshall and Randy Gellens for their helpful suggestions. Roger Marshall and Randy Gellens for their helpful suggestions.
11. References 11. References
11.1. Normative References 11.1. 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", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
January 2004. DOI 10.17487/RFC3688, January 2004,
<http://www.rfc-editor.org/info/rfc3688>.
[RFC5031] Schulzrinne, H., "A Uniform Resource Name (URN) for
Emergency and Other Well-Known Services", RFC 5031,
DOI 10.17487/RFC5031, January 2008,
<http://www.rfc-editor.org/info/rfc5031>.
[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, DOI 10.17487/RFC5222, August 2008,
<http://www.rfc-editor.org/info/rfc5222>.
[RFC5687] Tschofenig, H. and H. Schulzrinne, "GEOPRIV Layer 7 [RFC5687] Tschofenig, H. and H. Schulzrinne, "GEOPRIV Layer 7
Location Configuration Protocol: Problem Statement and Location Configuration Protocol: Problem Statement and
Requirements", RFC 5687, March 2010. Requirements", RFC 5687, DOI 10.17487/RFC5687, March 2010,
<http://www.rfc-editor.org/info/rfc5687>.
[RFC5985] Barnes, M., "HTTP-Enabled Location Delivery (HELD)", [RFC5985] Barnes, M., Ed., "HTTP-Enabled Location Delivery (HELD)",
RFC 5985, September 2010. RFC 5985, DOI 10.17487/RFC5985, September 2010,
<http://www.rfc-editor.org/info/rfc5985>.
[RFC6443] Rosen, B., Schulzrinne, H., Polk, J., and A. Newton, [RFC6443] Rosen, B., Schulzrinne, H., Polk, J., and A. Newton,
"Framework for Emergency Calling Using Internet "Framework for Emergency Calling Using Internet
Multimedia", RFC 6443, December 2011. Multimedia", RFC 6443, DOI 10.17487/RFC6443, December
2011, <http://www.rfc-editor.org/info/rfc6443>.
[RFC6881] Rosen, B. and J. Polk, "Best Current Practice for [RFC6881] Rosen, B. and J. Polk, "Best Current Practice for
Communications Services in Support of Emergency Calling", Communications Services in Support of Emergency Calling",
BCP 181, RFC 6881, March 2013. BCP 181, RFC 6881, DOI 10.17487/RFC6881, March 2013,
<http://www.rfc-editor.org/info/rfc6881>.
11.2. Informative References 11.2. Informative References
[M493] European Telecommunications Standards Institute, [M493] European Telecommunications Standards Institute,
"Functional architecture to support European requirements "Functional architecture to support European requirements
on emergency caller location determination and transport", on emergency caller location determination and transport",
ES 203 178, V 1.0.5, December 2014. ES 203 178, V 1.0.5, December 2014.
[RFC5986] Thomson, M. and J. Winterbottom, "Discovering the Local [RFC5986] Thomson, M. and J. Winterbottom, "Discovering the Local
Location Information Server (LIS)", RFC 5986, Location Information Server (LIS)", RFC 5986,
September 2010. DOI 10.17487/RFC5986, September 2010,
<http://www.rfc-editor.org/info/rfc5986>.
[RFC6155] Winterbottom, J., Thomson, M., Tschofenig, H., and R. [RFC6155] Winterbottom, J., Thomson, M., Tschofenig, H., and R.
Barnes, "Use of Device Identity in HTTP-Enabled Location Barnes, "Use of Device Identity in HTTP-Enabled Location
Delivery (HELD)", RFC 6155, March 2011. Delivery (HELD)", RFC 6155, DOI 10.17487/RFC6155, March
2011, <http://www.rfc-editor.org/info/rfc6155>.
[RFC6915] Bellis, R., "Flow Identity Extension for HTTP-Enabled [RFC6915] Bellis, R., "Flow Identity Extension for HTTP-Enabled
Location Delivery (HELD)", RFC 6915, April 2013. Location Delivery (HELD)", RFC 6915, DOI 10.17487/RFC6915,
April 2013, <http://www.rfc-editor.org/info/rfc6915>.
[RFC7216] Thomson, M. and R. Bellis, "Location Information Server [RFC7216] Thomson, M. and R. Bellis, "Location Information Server
(LIS) Discovery Using IP Addresses and Reverse DNS", (LIS) Discovery Using IP Addresses and Reverse DNS",
RFC 7216, April 2014. RFC 7216, DOI 10.17487/RFC7216, April 2014,
<http://www.rfc-editor.org/info/rfc7216>.
Authors' Addresses Authors' Addresses
James Winterbottom James Winterbottom
Winterb Consulting Services Winterb Consulting Services
Gwynneville, NSW 2500 Gwynneville, NSW 2500
AU AU
Phone: +61 448 266004 Phone: +61 448 266004
Email: a.james.winterbottom@gmail.com Email: a.james.winterbottom@gmail.com
Hannes Tschofenig Hannes Tschofenig
Halls in Tirol 6060 Halls in Tirol 6060
Austria Austria
Phone:
Email: Hannes.Tschofenig@gmx.net Email: Hannes.Tschofenig@gmx.net
URI: http://www.tschofenig.priv.at URI: http://www.tschofenig.priv.at
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:
Email: L.Liess@telekom.de Email: L.Liess@telekom.de
URI: http://www.telekom.de URI: http://www.telekom.de
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