Internet Engineering Task Force
Internet Draft Wu/Schulzrinne
Columbia University
wu-iptel-locswitch-00.txt
February 7, 2004
Expires: August 2004
Location-switch for Call Processing Language (CPL)
STATUS OF THIS MEMO
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026.
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Abstract
This document introduces two switch nodes named location-switch and
location-relation-switch to the Call Processing Language (CPL). The
new nodes enable CPL to handle location-based services.
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Table of Contents
1 Introduction ........................................ 2
1.1 Conventions of This Document ........................ 2
2 Terminology ......................................... 2
3 Location Switches ................................... 3
4 Location-relation Switches .......................... 5
5 IANA Considerations ................................. 7
5.1 URN Sub-Namespace Registration for
urn:ietf:params:xml:ns:cpl:location-switch ..................... 7
5.2 Schema registration ................................. 7
6 Examples ............................................ 8
A The XMl Schema for CPL location-switch and
location-relation-switch ....................................... 9
B Authors' Addresses .................................. 16
C Normative References ................................ 17
D Informative References .............................. 17
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1 Introduction
The Call Processing Language (CPL) [1] is a language that can be used
to describe and control Internet telephony services. CPL uses switch
nodes to check call conditions so as to make call control decisions.
This document introduces two new switch nodes named location-switch
and location-relation-switch. The new switch nodes check people's
physical locations and based on the location information to make call
control decisions.
Numerous applications today can get and share location information.
Location information may affect people on making call control
decisions. For example, in a place requiring quiet environment, it
is preferred to reject phone calls. There are two types of location
information. One is to describe location attributes, such as privacy
preference of a location. The other is to define physical locations,
such as geographical coordinates, or civil addresses. Both types of
location information can be encapsulated into XML-based Presence
Information Data Format (PIDF [6]). The encapsulation of location
attributes is defined in RPID -- Rich Presence Information Data
Format [7]. The encapsulation of physical location information is
defined in Presence-based GEOPRIV Location Object Format [8]. The
switch nodes defined in this document are used to handle physical
location information. The location attribute handling should be
defined in different switch nodes.
1.1 Conventions of This Document
In this document, the key words "MUST", "MUST NOT", "REQUIRED",
"SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",
and "OPTIONAL" are to be interpreted as described in RFC 2119 [2].
2 Terminology
This document uses the terms defined in [1]. We list additional
definitions that are related to location switches below:
Location occupier: A person whose current location will be
matched against the location specified in a location-
switch.
Script owner: For a location-switch, script owner refers to the
person who owns the CPL script that contains the location-
switch.
Location relation: The relationship between two persons
regarding their physical locations. The relationship can be
the distance between two persons, or the relative positions
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between two persons, e.g., person A is south of person B.
3 Location Switches
Location switches allow a CPL script to make call decisions based on
the physical location of a location occupier. They are summarized in
Figure 1.
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Node: "location-switch"
Outputs: "location" Specific location to match
Parameters: "type" "geospatial", "civil"
"uri" the location occupier's uri
Output: "location"
Parameters: "longitude" Longitude coordinates,
valid only for geospatial type
"latitude" Latitude coordinates,
valid only for geospatial type
"altitude" Altitude coordinates,
valid only for geospatial type
"country" Country of the location,
valid only for civil type
"A1" National subdivisions
(state, region, province, prefecture),
valid only for civil type
"A2" County, parish, gun (JP), district (IN),
valid only for civil type
"A3" City, township, shi (JP),
valid only for civil type
"A4" City division, borough, city district, ward,
chou (JP), valid only for civil type
"A5" neighborhood, block,
valid only for civil type
"A6" street, valid only for civil type
"PRD" Leading street direction,
valid only for civil type
"POD" Trailing street suffix,
valid only for civil type
"STS" Street suffix, valid only for civil type
"HNO" House number, numeric part only,
valid only for civil type
"HNS" House number suffix,
valid only for civil type
"LMK" Landmark or vanity address,
valid only for civil type
"LOC" Additional location information, such as room
valid only for civil type
"FLR" Floor, valid only for civil type
"NAM" Name (residence, business or office occupant)
valid only for civil type
"PC" Postal code, valid only for civil type
"distance" Distance value to a specified location.
Valid only if geospatial or
civil location presented.
"condition" Valid only if distance presented.
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Value is (in|out|at|). Default value is "at".
"unit" Valid only if distance presented.
Value is (m|km|mi|in|ft|yd|naut mi).
Default value is "m".
"direction" Direction relative to a specified location,
Valid only if geospatial or
civil location presented. Value is
"(south|north|west|east|above|below)".
Figure 1: Syntax of the "location-switch" node
Location switches have two node parameters: The mandatory parameter
"type" specifies the location type to match: either geospatial
location, or civil location. The optional parameter "uri" specifies
the location occupier's uri. If not provided, the location occupier
will be the script owner.
The "location" output tag may have one or more parameters, indicating
the exact location to match.
The "longitude", "latitude", and "altitude" are used to specify a
geographical location. The country, "A1", "A2", "A3", "A4", "A5",
"A6", "PRD", "POD", "STS", "HNO", "HNS", "LMK", "LOC", "FLR", "NAM",
and "PC" are used to specify a civil location.
The "distance" parameter cannot be used without geographical location
or civil location specified. Usually, the distance parameter is used
with geographical location since it is difficult to meature the
distance to a civil location. The "condition" and "unit" parameters
are used to provide more convinient ways for distance specification.
The available unit values are (m|km|mi|in|ft|yd|naut mi), mapped to
meter, kilometer, mile, inch, foot, yard, and nautical mile,
accordingly.
The "direction" parameter cannot be used without geographical
location or civil location specified. The value "south" or "north"
are usually used when latitude specified. The value "east" or "west"
are usually used when longitude specified. The value "above" and
"below" are usually used when altitude specified, or FLR sepcified.
4 Location-relation Switches
Location-relation switches allow a CPL script to make call decisions
based on the location relation of two persons. They are summarized in
Figure 2.
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Node: "location-relation-switch"
Outputs: "location-relation" Specific location relation to match
Parameters: "uri1" the first location occupier's uri
"uri2" the second location occupier's uri
Output: "location-relation"
Parameters: "distance" Distance value between two persons.
"condition" Valid only if distance presented.
Value is (in|out|at|).
Default value is "at".
"unit" Valid only if distance presented.
Value is (m|km|mi|in|ft|yd
|naut mi). Default value is "m".
"direction" Direction relation between two
persons, value is "(south|north|
west|east|above|below)".
"same" A space separated list containing
location attributes, e.g., LOC, that
two persons have the same value.
"difference" A space separated list containing
location attributes, that two
persons have different values.
Figure 2: Syntax of the "location-relation-switch" node
Location-relation switches have two node parameters: The mandatory
parameter "uri1" specifies the first location occupier's uri. The
optional parameter "uri2" specifies the second location occupier's
uri. If not provided, the second location occupier will be the script
owner.
The "location-relation" output tag may have one or more parameters,
indicating the exact relation to match.
The "distance" parameter indicates the distance between two persons.
The "condition" and "unit" parameters are used for distance
measuring. They have the same meanings as those defined in
"location-switch".
The "direction" parameter indicates relative positions between two
persons. For example, "south" means uri1 is south of uri2.
The "same" and "difference" indicating the relationship between two
persons' location attributes. The attributes can be geospatial
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location attributes, such as "longitude", "latitude", and "altitude".
They can also be civil location attributes, such as country, "A1",
"A2", "A3", "A4", "A5", "A6", "PRD", "POD", "STS", "HNO", "HNS",
"LMK", "LOC", "FLR", "NAM", and "PC".
5 IANA Considerations
This document registers a new URN per RFC 2141 [3], RFC 2648 [4], and
RFC 3688 [5].
5.1 URN Sub-Namespace Registration for
urn:ietf:params:xml:ns:cpl:location-switch
URI: urn:ietf:params:xml:ns:cpl:location-switch
Registrant Contact: Xiaotao Wu <xiaotaow@cs.columbia.edu>
Henning Schulzrinne <hgs@cs.columbia.edu>
XML:
BEGIN
<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN"
"http://www.w3.org/TR/xhtml-basic/xhtml-basic10.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="content-type"
content="text/html;charset=iso-8859-1"/>
<title>Call Processing Language location-switch Namespace
</title>
</head>
<body>
<h1>Namespace for Call Processing Language location-switch</h1>
<h2>urn:ietf:params:xml:ns:cpl:location-switch</h2>
<p><a href="[[[URL of published RFC]]]">RFCXXXX</a>.</p>
</body>
</html>
END
5.2 Schema registration
This specification registers XML Schema for CPL location-switch, and
location-relation-switch, as per the guidelines in [5].
URI: please assign.
Registrant contact:
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Xiaotao Wu <xiaotaow@cs.columbia.edu>
Henning Schulzrinne <hgs@cs.columbia.edu>
XML: The XML can be found in Section A.
6 Examples
The script in Figure 3 is a simple script which reject all calls when
the script owner is in conference-room.
<?xml version="1.0" encoding="UTF-8"?>
<cpl xmlns="urn:ietf:params:xml:ns:cpl"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="urn:ietf:params:xml:ns:cpl cpl.xsd
urn:ietf:params:xml:ns:cpl:location-switch location-switch.xsd">
<incoming>
<location-switch type="civil">
<location LOC="conference-room">
<reject status="busy"/>
</location>
</location-switch>
</incoming>
</cpl>
Figure 3: Example Script: Location based call rejection
The script in Figure 4 checks the location relation between the
script owner and sip:bob@examples.com, when it receives an event
notification showing that sip:bob@examples.com is online. If they
are at the same floor, the script will call sip:bob@examples.com.
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<?xml version="1.0" encoding="UTF-8"?>
<cpl xmlns:="urn:ietf:params:xml:ns:cpl:location-switch"
xmlns:CPL="urn:ietf:params:xml:ns:cpl"
xmlns:EVENT="urn:ietf:params:xml:ns:cpl:event"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="urn:ietf:params:xml:ns:cpl cpl.xsd
urn:ietf:params:xml:ns:cpl:event event.xsd
urn:ietf:params:xml:ns:cpl:location-switch locswitch.xsd">
<EVENT:notification>
<CPL:address-switch>
<CPL:address is="sip:bob@examples.com">
<EVENT:event-switch>
<EVENT:event is="open">
<location-relation-switch uri1="sip:bob@examples.com">
<location-relation distance="10" same="FLR">
<CPL:location url="sip:bob@examples.com">
<call/>
</CPL:location>
</location-relation>
</location-relation-switch>
</EVENT:event>
</EVENT:event-switch>
</CPL:address>
</CPL:address-switch>
</EVENT:notification>
</cpl>
Figure 4: Example Script: Location based call
A The XMl Schema for CPL location-switch and location-relation-switch
This section includes an XML schema describing the XML syntax of CPL
location-switch and location-relation-switch. The schema is based on
the XML schema for CPL.
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<?xml version="1.0" encoding="UTF-8"?>
<xs:schema targetNamespace="urn:ietf:params:xml:ns:cpl:location-switch"
xmlns="urn:ietf:params:xml:ns:cpl:location-switch"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:CPL="urn:ietf:params:xml:ns:cpl"
elementFormDefault="qualified"
attributeFormDefault="unqualified">
<xs:import namespace="urn:ietf:params:xml:ns:cpl"
schemaLocation="cpl.xsd"/>
<xs:complexType name="LocationSwitchType">
<xs:sequence>
<xs:element name="location" type="LocationType" minOccurs="0"
maxOccurs="unbounded"/>
<xs:sequence minOccurs="0">
<xs:element name="not-present" type="CPL:NotPresentAction"/>
<xs:element name="location" type="LocationType" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
<xs:element name="otherwise" type="CPL:OtherwiseAction"
minOccurs="0"/>
</xs:sequence>
<xs:attribute name="type" use="required">
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:enumeration value="geospatial"/>
<xs:enumeration value="civil"/>
</xs:restriction>
</xs:simpleType>
</xs:attribute>
<xs:attribute name="uri" type="xs:anyURI"/>
</xs:complexType>
<xs:element name="location-switch" type="LocationSwitchType"
substitutionGroup="CPL:switch"/>
<xs:complexType name="LocationType">
<xs:group ref="CPL:Node"/>
<xs:attribute name="longitude" type="xs:string">
<xs:annotation>
<xs:documentation>Valid only if type is
geospatial</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="latitude" type="xs:string">
<xs:annotation>
<xs:documentation>Valid only if type is
geospatial</xs:documentation>
</xs:annotation>
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</xs:attribute>
<xs:attribute name="altitude" type="xs:string">
<xs:annotation>
<xs:documentation>Valid only if type is
geospatial</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="A1" type="xs:string">
<xs:annotation>
<xs:documentation>Valid only if type is
civil</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="A2" type="xs:string">
<xs:annotation>
<xs:documentation>Valid only if type is
civil</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="A3" type="xs:string">
<xs:annotation>
<xs:documentation>Valid only if type is
civil</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="A4" type="xs:string">
<xs:annotation>
<xs:documentation>Valid only if type is
civil</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="A5" type="xs:string">
<xs:annotation>
<xs:documentation>Valid only if type is
civil</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="A6" type="xs:string">
<xs:annotation>
<xs:documentation>Valid only if type is
civil</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="PRD" type="xs:string">
<xs:annotation>
<xs:documentation>Valid only if type is
civil</xs:documentation>
</xs:annotation>
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</xs:attribute>
<xs:attribute name="POD" type="xs:string">
<xs:annotation>
<xs:documentation>Valid only if type is
civil</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="STS" type="xs:string">
<xs:annotation>
<xs:documentation>Valid only if type is
civil</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="HNO" type="xs:string">
<xs:annotation>
<xs:documentation>Valid only if type is
civil</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="HNS" type="xs:string">
<xs:annotation>
<xs:documentation>Valid only if type is
civil</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="LMK" type="xs:string">
<xs:annotation>
<xs:documentation>Valid only if type is
civil</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="LOC" type="xs:string">
<xs:annotation>
<xs:documentation>Valid only if type is
civil</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="FLR" type="xs:string">
<xs:annotation>
<xs:documentation>Valid only if type is
civil</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="NAM" type="xs:string">
<xs:annotation>
<xs:documentation>Valid only if type is
civil</xs:documentation>
</xs:annotation>
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</xs:attribute>
<xs:attribute name="PC" type="xs:string">
<xs:annotation>
<xs:documentation>Valid only if type is
civil</xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="distance">
<xs:annotation>
<xs:documentation>Valid only if geospatial or civil location
presented</xs:documentation>
</xs:annotation>
<xs:simpleType>
<xs:restriction base="xs:decimal">
<xs:minInclusive value="0"/>
</xs:restriction>
</xs:simpleType>
</xs:attribute>
<xs:attribute name="condition" default="at">
<xs:annotation>
<xs:documentation>Valid only if distance
presented</xs:documentation>
</xs:annotation>
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:enumeration value="in"/>
<xs:enumeration value="out"/>
<xs:enumeration value="at"/>
</xs:restriction>
</xs:simpleType>
</xs:attribute>
<xs:attribute name="unit" default="m">
<xs:annotation>
<xs:documentation>Valid only if distance
presented</xs:documentation>
</xs:annotation>
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:enumeration value="m"/>
<xs:enumeration value="km"/>
<xs:enumeration value="mi"/>
<xs:enumeration value="in"/>
<xs:enumeration value="ft"/>
<xs:enumeration value="yd"/>
<xs:enumeration value="naut mi"/>
</xs:restriction>
</xs:simpleType>
</xs:attribute>
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<xs:attribute name="direction">
<xs:annotation>
<xs:documentation>Valid only if geospatial or civil location
presented</xs:documentation>
</xs:annotation>
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:enumeration value="south"/>
<xs:enumeration value="north"/>
<xs:enumeration value="east"/>
<xs:enumeration value="west"/>
<xs:enumeration value="above"/>
<xs:enumeration value="below"/>
</xs:restriction>
</xs:simpleType>
</xs:attribute>
<xs:anyAttribute namespace="##other" processContents="lax"/>
</xs:complexType>
<xs:complexType name="LocationRelationSwitchType">
<xs:sequence>
<xs:element name="location-relation"
type="LocationRelationType" minOccurs="0"
maxOccurs="unbounded"/>
<xs:sequence minOccurs="0">
<xs:element name="not-present" type="CPL:NotPresentAction"/>
<xs:element name="location-relation"
type="LocationRelationType" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
<xs:element name="otherwise" type="CPL:OtherwiseAction"
minOccurs="0"/>
</xs:sequence>
<xs:attribute name="uri1" type="xs:anyURI" use="required"/>
<xs:attribute name="uri2" type="xs:anyURI"/>
</xs:complexType>
<xs:element name="location-relation-switch"
type="LocationRelationSwitchType"
substitutionGroup="CPL:switch"/>
<xs:simpleType name="LocationAttributes">
<xs:restriction base="xs:string">
<xs:enumeration value="latitude"/>
<xs:enumeration value="longitude"/>
<xs:enumeration value="altitude"/>
<xs:enumeration value="country"/>
<xs:enumeration value="A1"/>
<xs:enumeration value="A2"/>
<xs:enumeration value="A3"/>
<xs:enumeration value="A4"/>
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<xs:enumeration value="A5"/>
<xs:enumeration value="A6"/>
<xs:enumeration value="PRD"/>
<xs:enumeration value="POD"/>
<xs:enumeration value="STS"/>
<xs:enumeration value="HNO"/>
<xs:enumeration value="HNS"/>
<xs:enumeration value="LMK"/>
<xs:enumeration value="LOC"/>
<xs:enumeration value="FLR"/>
<xs:enumeration value="NAM"/>
<xs:enumeration value="PC"/>
</xs:restriction>
</xs:simpleType>
<xs:complexType name="LocationRelationType">
<xs:group ref="CPL:Node"/>
<xs:attribute name="distance">
<xs:annotation>
<xs:documentation>Valid only if geospatial or civil location
presented</xs:documentation>
</xs:annotation>
<xs:simpleType>
<xs:restriction base="xs:decimal">
<xs:minInclusive value="0"/>
</xs:restriction>
</xs:simpleType>
</xs:attribute>
<xs:attribute name="condition" default="at">
<xs:annotation>
<xs:documentation>Valid only if distance
presented</xs:documentation>
</xs:annotation>
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:enumeration value="in"/>
<xs:enumeration value="out"/>
<xs:enumeration value="at"/>
</xs:restriction>
</xs:simpleType>
</xs:attribute>
<xs:attribute name="unit" default="m">
<xs:annotation>
<xs:documentation>Valid only if distance
presented</xs:documentation>
</xs:annotation>
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:enumeration value="m"/>
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<xs:enumeration value="km"/>
<xs:enumeration value="mi"/>
<xs:enumeration value="in"/>
<xs:enumeration value="ft"/>
<xs:enumeration value="yd"/>
<xs:enumeration value="naut mi"/>
</xs:restriction>
</xs:simpleType>
</xs:attribute>
<xs:attribute name="direction">
<xs:annotation>
<xs:documentation>Valid only if geospatial or civil location
presented</xs:documentation>
</xs:annotation>
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:enumeration value="south"/>
<xs:enumeration value="north"/>
<xs:enumeration value="east"/>
<xs:enumeration value="west"/>
<xs:enumeration value="above"/>
<xs:enumeration value="below"/>
</xs:restriction>
</xs:simpleType>
</xs:attribute>
<xs:attribute name="same">
<xs:simpleType>
<xs:list itemType="LocationAttributes"/>
</xs:simpleType>
</xs:attribute>
<xs:attribute name="difference">
<xs:simpleType>
<xs:list itemType="LocationAttributes"/>
</xs:simpleType>
</xs:attribute>
<xs:anyAttribute namespace="##other" processContents="lax"/>
</xs:complexType>
</xs:schema>
B Authors' Addresses
Xiaotao Wu
Dept. of Computer Science
Columbia University
1214 Amsterdam Avenue, MC 0401
New York, NY 10027
USA
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electronic mail: xiaotaow@cs.columbia.edu
Henning Schulzrinne
Dept. of Computer Science
Columbia University
1214 Amsterdam Avenue, MC 0401
New York, NY 10027
USA
electronic mail: schulzrinne@cs.columbia.edu
C Normative References
[1] J. Lennox, X. Wu, and H. Schulzrinne, "CPL: a language for user
control of Internet telephony services," internet draft, Internet
Engineering Task Force, Aug. 2003. Work in progress.
[2] S. Bradner, "Key words for use in RFCs to indicate requirement
levels," RFC 2119, Internet Engineering Task Force, Mar. 1997.
[3] R. Moats, "URN syntax," RFC 2141, Internet Engineering Task
Force, May 1997.
[4] R. Moats, "A URN namespace for IETF documents," RFC 2648,
Internet Engineering Task Force, Aug. 1999.
[5] M. Mealling, "The ietf xml registry," RFC 3688, Internet
Engineering Task Force, Jan. 2004.
D Informative References
[6] H. Sugano, S. Fujimoto, et al., "Presence information data format
(PIDF)," internet draft, Internet Engineering Task Force, May 2003.
Work in progress.
[7] H. Schulzrinne, "RPID -- rich presence information data format,"
internet draft, Internet Engineering Task Force, July 2003. Work in
progress.
[8] J. Peterson, "A presence-based GEOPRIV location object format,"
Internet Draft draft-ietf-geopriv-pidf-lo-00, Internet Engineering
Task Force, Jan. 2004. Work in progress.
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Internet Draft wu-iptel-locswitch February 7, 2004
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