D.2 state-and-event-info XML schema

24.2373GPPIP Multimedia (IM) Core Network (CN) subsystem IP Multimedia Subsystem (IMS) service continuityRelease 17Stage 3TS

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

D.2.1 General

This subclause defines XML schema and MIME type for session state and event information. It is used in the present document for the PS to CS SRVCC for calls in alerting phase, for accepting of a call in alerting state transferred by the PS-PS access transfer procedures, for the PS to CS SRVCC for originating calls in pre-alerting phase, for PS to CS SRVCC for terminating calls in pre-alerting phase and for requesting and providing remote leg information.

D.2.2 XML schema

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

<xs:schema

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

elementFormDefault="qualified"

attributeFormDefault="unqualified">

<xs:simpleType name="directionType">

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

<xs:enumeration value="initiator"/>

<xs:enumeration value="receiver"/>

</xs:restriction>

</xs:simpleType>

<xs:element name="state-and-event-info" type="Tstate-and-event-info"/>

<xs:complexType name="Tstate-and-event-info">

<xs:sequence>

<xs:element name="state-info" type="xs:string" minOccurs="0" maxOccurs="1"/>

<xs:element name="direction" type="directionType" minOccurs="0" maxOccurs="1"/>

<xs:element name="event" type="xs:string" minOccurs="0" maxOccurs="1"/>

<xs:element name="anyExt" type="anyExtType" minOccurs="0" />

<xs:any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>

</xs:sequence>

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

</xs:complexType>

<xs:complexType name="anyExtType">

<xs:sequence>

<xs:any namespace="##any" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>

</xs:sequence>

</xs:complexType>

<xs:element name="remoteLegInfoRequest" type="anyExtType"/>

<xs:element name="remoteLegInfoResponse" type="anyExtType"/>

<xs:complexType name="dialogIdType">

<xs:sequence>

<xs:any namespace="##any" processContents="lax" minOccurs="0" maxOccurs="unbounded"/>

</xs:sequence>

<xs:attribute name="call-id" type="xs:string"/>

<xs:attribute name="local-tag" type="xs:string" use="optional"/>

<xs:attribute name="remote-tag" type="xs:string" use="optional"/>

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

</xs:complexType>

<!– elements which can be included in remoteLegInfoRequest –>

<xs:element name="localAssertedIdRequest"/>

<xs:element name="dialogIdRequest"/>

<!– elements which can be included in remoteLegInfoResponse–> <xs:element name="localAssertedId" type="xs:anyURI"/>

<xs:element name="dialogId" type="dialogIdType"/>

</xs:schema>

D.2.3 XML schema description

This subclause describes the elements of the state-and-info XML Schema.

<state-and-event-info>: The <state-and-event-info> element is used to indicate state and event information related to a specific dialog. In the present document, it is used to communicate information between the SCC AS and the MSC-server for the purpose of PS to CS SRVCC for calls in alerting phase, for UE to communicate acceptance of incoming alerting phase call transferred using PS-PS access transfer procedures and communicate information between the SCC AS and the MSC server for the purpose of the PS to CS SRVCC for originating calls in pre-alerting phase.

<state-info>: The <state-info> element is used to indicate the state of the dialog and is modelled on the FSM described in IETF RFC 4235 [48]. In the present document, it can only have the values specified in table D.2.3-1 for state-info-values.

Table D.2.3-1: ABNF syntax of values of the <state-info> element

state-info-values = early-value / pre-alerting-value

early-value = %x65.61.72.6c.79 ; "early"

pre-alerting-value = %x70.72.65.2d.61.6c.65.72.74.69.6e.67 ; "pre-alerting"

<direction>: The <direction> element indicates whether the observed user was the initiator of the dialog, or the recipient of the INVITE that created it. It can only have the values specified in table D.2.3-2 for direction-values. In the present document it must be included together with the <state-info> element.

Table D.2.3-2: ABNF syntax of values of the <direction> element

direction-values = initiator-value / receiver-value

initiator-value = %x69.6e.69.74.69.61.74.6f.72 ; "initiator"

receiver-value = %x72.65.63.65.69.76.65.72 ; "receiver"

<event>: The <event> element is used to communicate an event that causes a dialog state transition. In the present document, the <event> element can only have the values specified in table D.2.3-3 for event-values.

Table D.2.3-3: ABNF syntax of values of the <event> element

event-values = call-accepted-value / alerting-started-value

call-accepted-value = %x63.61.6c.6c.2d.61.63.63.65.70.74.65.64 ; "call-accepted"

alerting-started-value = %x61.6c.65.72.74.69.6e.67.2d.73.74.61.72.74.65.64 ; "alerting-started"

<anyExt>: The <anyExt> element is used to convey extensions. In the present document, the <anyExt> element contains a <remoteLegInfoRequest> element or a <remoteLegInfo> element.

NOTE 1: The subelements of the <anyExt> are validated by the <xs:any namespace="##any" processContents="lax" minOccurs="0" maxOccurs="unbounded"/> particle of the <anyExt> element.

<remoteLegInfoRequest> The <remoteLegInfoRequest>element indicates request for the remote leg information. The <remoteLegInfoRequest> element contains the optional <localAssertedIdRequest> element and the optional <dialogIdRequest> element.

NOTE 2: The subelements of the <remoteLegInfoRequest> are validated by the <xs:any namespace="##any" processContents="lax" minOccurs="0" maxOccurs="unbounded"/> particle of the <anyExt> element.

<localAssertedIdRequest> The <localAssertedIdRequest> element indicates that SCC AS is to provide <localAssertedId> in the <remoteLegInfoResponse>.

<dialogIdRequest> The <dialogIdRequest> element indicates that SCC AS is to provide <dialogId> in the <remoteLegInfoResponse>.

<remoteLegInfoResponse> The <remoteLegInfoResponse> indicates the remote leg information. The <remoteLegInfoResponse> element contains the optional <localAssertedId> element and the optional <dialogId> element.

NOTE 3: The subelements of the <remoteLegInfoResponse> are validated by the <xs:any namespace="##any" processContents="lax" minOccurs="0" maxOccurs="unbounded"/> particle of the <anyExt> element.

<localAssertedId> The <localAssertedId> element contains URI provided by SCC AS in P-Asserted-Identity header field towards remote UE in remote leg associated with the dialog within which the SIP INFO request is sent.

<dialogId> The <dialogId> element contains dialog identifier of remote leg associated with the dialog within which the SIP INFO request is sent, i.e. the "call-id" attribute containing the call-id of the remote leg, the optional "local-tag" attribute containing tag that would be viewed as the local tag of the remote leg from the perspective of SCC AS and the optional "remote-tag" attribute containing tag that would be viewed as the remote tag of the remote leg from the perspective of SCC AS.

Recipient of the XML ignores any unknown element and any unknown attribute.

D.2.4 IANA registration template

Your Name:

Your Email Address:

Media Type Name:

Application

Subtype name:

vnd.3gpp.state-and-event-info+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 section 9.1 of IETF RFC 7303.

Encoding considerations:

binary.

Security considerations:

Same as general security considerations for application/xml media type as specified in section 9.1 of IETF RFC 7303. In addition, this media type provides a format for exchanging information in SIP, so the security considerations from IETF RFC 3261apply.

The information transported in this 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.

This media type does not include provisions for directives that institute actions on a recipient’s files or other resources.

This media type does not include provisions for directives that institute actions that, while not directly harmful to the recipient, may result in disclosure of information that either facilitates a subsequent attack or else violates a recipient’s privacy in any way.

This media type does not employ compression.

Interoperability considerations:

Same as general interoperability considerations for application/xml media type as specified in section 9.1 of IETF RFC 7303.

Published specification:

3GPP TS 24.237 "IP Multimedia Subsystem (IMS) Service Continuity", version 13.1.0, available via http://www.3gpp.org/specs/numbering.htm.

Applications which use this media type:

Applications supporting the service continuity as described in the published specification.

Fragment identifier considerations:

The handling in section 5 of IETF RFC 7303 applies.

Restrictions on usage:

None

Provisional registration? (standards tree only):

N/A

Additional information:

1. Deprecated alias names for this type: none

2. Magic number(s): none

3. File extension(s): none

4. Macintosh File Type Code(s): none

5. Object Identifier(s) or OID(s): none

Intended usage:

Common

Person to contact for further information:

– Name: <MCC name>

– Email: <MCC email address>

– Author/Change controller:

i) Author: 3GPP CT1 Working Group/3GPP_TSG_CT_WG1@LIST.ETSI.ORG

ii) Change controller: <MCC name>/<MCC email address>