C.3 IUT preferences XML schema

24.3373GPPIP Multimedia (IM) Core Network (CN) subsystem IP Multimedia Subsystem (IMS) inter-UE transferRelease 17Stage 3TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

C.3.1 General

This subclause defines XML schema and MIME type related to IUT user preferences.

The IUT service contains a rule set that specifies how the IUT service shall react to external stimuli.

The AUID of the IUT user preferences XCAP application usage is "org.3gpp.iut".

The default namespace of the IUT user preferences XCAP application usage is "urn:3gpp:ns:iut:1.0".

The MIME type of the IUT user preferences XML document is specified in annex C.4.

C.3.2 Structure of the XML document

C.3.2.1 IUT element

The IUTconfiguration can contain a Controller Loss Preferences element and a rule set.

The rule set reuses the syntax as specified by the common policy draft (see IETF RFC 4745 [42]).

<cp:ruleset>

rule1

rule2

</cp:ruleset>

</iut>

In general the following procedure applies:

When the service processes a set of rules it shall start with the first rule and test if its conditions are all true, if this is the case the rule matches and the specified action shall be executed.

When the rule does not match the following rule shall be selected and the same procedure repeated, until a matching rule is found or the set of remaining rules is empty.

In subclause C.3.2.4 all allowed conditions are specified, normally rules are evaluated at communication setup time, for conditions where this is not the case this is explicitly indicated.

C.3.2.2 IUT rules

The IUT service is configured with an ordered set of IUT rules. The XML Schema reuses the rule syntax as specified by the common policy draft (see IETF RFC 4745 [42]). The rules take the following form:

<cp:rule id="rule66">

<cp:conditions>

condition1

condition2

</cp:conditions>

<cp:actions>

<enable-collaborative-sessions/>

</cp:actions>

</cp:rule>

To give more guidance, examples of rules are shown below:

<cp:rule id="rule66">

<cp:conditions>

<cp:identity>

<cp:one>id=serveduser@domain</cp:one>

</cp:identity>

</cp:conditions>

<cp:actions>

<enable-collaborative-sessions/>

</cp:actions>

</cp:rule>

<cp:rule id="rule66">

<cp:conditions/>

<cp:actions>

<controller-loss-preferences>

</controller-loss-preference>

</cp:actions>

</cp:rule>

When the service processes a set of rules it shall start with the first rule and test if its conditions are all true, if this is the case the rule matches and the specified action is executed. When a rule matches remaining rules in the rule set shall be discarded. Applied to the fragment above this means that only if the expression (condition1 AND condition2) evaluates to true that then the rule66 matches and the forward-to action is executed.

When the rule does not match the following rule shall be selected and the same procedure repeated, until a matching rule is found or the set of remaining rules is empty.

The "id" attribute value of a rule shall uniquely identify the rule within a rule set. This can be used in XCAP usage to address one specific rule.

C.3.2.3 IUT rule conditions

The following conditions are allowed by the XML Schema for IUT service:

– cp:identity: This condition evaluates to true when the calling user’s identity matches with the value of the identity element. The interpretation of all the elements of this condition is described in OMA-TS-XDM-Core-V1_1 [45]. In all other cases the condition evaluates to false. The Identity shall be matched against the value taken from the P-Asserted-Identity header field, and in addition as an option matched against the From header field and/or the Referred-By header field, unless both the <identity> element value and the Contact header field value contain a "gr" parameter, then the <identity> element value shall be matched against the value taken from the Contact header field;

– anonymous: This condition evaluates to true when the P-Asserted-Identity of the calling user is not provided or privacy restricted;

– media: When the incoming call request for certain media, the forwarding rule can decide to forward the call for this specific media. This condition evaluates to true when the value of this condition matches the media field in one of the "m=" lines in the SDP (IETF RFC 4566 [41]) offered in an INVITE request (IETF RFC 3261 [26]).

NOTE: As described in IETF RFC 4745 [42] the case of unconditional evaluates to be true in all cases where all other reasons are not applicable. Collaborative sessions are enabled as soon as the served user is the called user. The indication of unconditional is the absence of any reason element in the cp:conditions element.

The following conditions are allowed by the XML Schema for the IUT service:

– ICSI: This condition evaluates to true when the value of the ICSI element matches with a URI parameter in the P-Asserted-Service header field;

– RequestURI: This condition evaluates to true when the value of the RequestURI element matches with the Request-URI.

Information of which of the above mentioned conditions the user is allowed to use can be obtained from the network by using the schema defined in subclause C.3.3.

C.3.2.4 IUT rule actions

The action supported by the CDIV service is forwarding of calls. For this the forward-to action has been defined. The forward-to action takes the following elements:

enable-collaborative-sessions: specifies that collaborative sessions are enabled.

controller-loss-preferences: candidate UEs in controller loss preferences can be configured using the value of the <controller> child element of the <controller-loss-preferences> element. Each <controller> element contains a URI. The URI identifies a UE that is a candidate UE for controller loss preference in priority order.

C.3.3 XML schema

<?xml version="1.0" encoding="UTF-8"?>

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"

xmlns:iut="urn:3gpp:ns:iut:1.0"

xmlns:cp="urn:ietf:params:xml:ns:common-policy"

xmlns:ocp="urn:oma:xml:xdm:common-policy"

targetNamespace="urn:3gpp:ns:iut:1.0"

elementFormDefault="qualified"

attributeFormDefault="unqualified">

<!– import common policy definitions –>

<xs:import namespace="urn:ietf:params:xml:ns:common-policy" schemaLocation="common-policy.xsd"/>

<!– import OMA common policy extensions –>

<xs:import namespace="urn:oma:xml:xdm:common-policy" schemaLocation="OMA-SUP-XSD_xdm_commonPolicy-V1_0_2-20070830-A.xsd"/>

<!– IUT specific extensions to IETF common policy conditions –>

<!– IUT rule set based on the common policy rule set.–>

<xs:element name="iut">

<xs:annotation>

<xs:documentation>This is the IUT configuration document.</xs:documentation>

</xs:annotation>

<xs:complexType>

<xs:sequence>

<xs:element ref="cp:ruleset" minOccurs="0"/>

</xs:sequence>

<xs:attribute name="active" type="xs:boolean" use="optional" default="true"/>

<xs:anyAttribute namespace="##any" processContents="lax"/>

</xs:complexType>

</xs:element>

<!– iut specific to extensions IETF common policy conditions –>

<xs:element name="anonymous" type="iut:empty-element-type"/>

<xs:element name="RequestURI" type="xs:anyURI"/>

<xs:element name="ICSI" type="xs:string"/>

<xs:complexType name="supported-media-type">

<xs:choice>

<xs:element name="all-media" type="iut:empty-element-type"/>

<xs:element name="no-media" type="iut:empty-element-type"/>

<xs:sequence maxOccurs="unbounded">

<xs:element name="media" type="iut:media-type"/>

</xs:sequence>

<xs:any namespace="##other" processContents="lax"/>

</xs:choice>

</xs:complexType>

<!– iut specific extensions to IETF common policy actions–>

<xs:element name="enable-collaborative-sessions" type="iut:empty-element-type"/>

<xs:element name="controller-loss-preferences">

<xs:complexType>

<xs:sequence>

<xs:element name="controller" type="xs:anyURI" minOccurs="0" maxOccurs="unbounded"/>

</xs:sequence>

</xs:complexType>

</xs:element>

<!– utility xml elements –>

<xs:complexType name="empty-element-type"/>

<xs:simpleType name="media-type" final="list restriction">

<xs:restriction base="xs:string"/>

</xs:simpleType>

</xs:schema>

C.3.4 IANA registration template

Editor’s note: The MIME type "application/vnC.3gpp.iut-config+xml" as defined in this subclause is to be registered in the IANA registry for Application Media Types based upon the following template.

MIME media type name:

Application.

MIME subtype name:

vnC.3gpp.iut-config+xml.

Required parameters:

None.

Optional parameters:

"charset" the parameter has identical semantics to the charset parameter of the "application/xml" media type as specified in IETF RFC 3023 [29].

Encoding considerations:

binary.

Security considerations:

Same as general security considerations for application/xml as specified in section 10 of IETF RFC 3023 [29]. In addition, this content type provides a format for exchanging information in SIP, so the security considerations from IETF RFC 3261 [30] apply. Furthermore, 3GPP has defined mechanisms for ensuring the privacy and integrity protection of the bodies of XCAP messages used in the 3GPP IM CN Subsystem.

The information transported in this MIME media type does not include active or executable content.

Mechanisms for privacy and integrity protection of protocol parameters exist. Those mechanisms as well as authentication and further security mechanisms are described in 3GPP TS 24.229 [7].

Interoperability considerations:

Same as interoperability considerations as specified in section 3.1 of IETF RFC 3023 [29].

Published specification:

3GPP TS 24.337: "IP Multimedia Subsystem (IMS) inter-UE transfer; Stage 3"

Applications which use this media:

Applications that use the 3GPP IM CN Subsystem as defined by 3GPP.

Intended usage:

COMMON

Additional information:

1. Magic number(s): none

2. File extension(s): none

3. Macintosh file type code: none

4. Object Identifiers: none