A.16 Support for volume based charging of IMS services

29.2143GPPPolicy and charging control over Rx reference pointRelease 17TS

As a network option, when VBC feature is supported, the P-CSCF may be able to indicate to the PCRF the establishment and termination of specific IMS communication services (e.g. CAT and voice calls, 3PTY conference) or the establishment and termination of different communication dialogues to separate parties. This enables PCC to apply different Policy and Charging control. During AF session establishment, the P-CSCF may include the IMS-Content-Identifier AVP and the IMS-Content-Type AVP in the AAR command towards the PCRF. The PCRF derives the PCC rules to categorise the service data flows by rating group or combination of rating group and service id.

During AF session modification, the P-CSCF may include the IMS-Content-Identifier AVP and the IMS-Content-Type AVP in the AAR command towards the PCRF. The PCRF updates the PCC rules to categorise the service data flows by rating group or combination of rating group and service id.

The IMS-Content-Type AVP indicates the type of IMS content of a session component. The P-CSCF determines the type of IMS content as follows:

– If the SDP payload refers to the Customized Alerting Tones (CAT) service (i.e. SDP body contains a media-level "a=content" SDP attribute with a value "g.3gpp.cat" defined in 3GPP TS 24.182 [62]), the P-CSCF sets the IMS-Content-Type AVP with the value "CAT".

– If the SDP payload refers to the 3PTY conference service (i.e. SDP body contains an "a=content" media-level attribute line with value of "g.3gpp.conf" defined in 3GPP TS 24.147 [63]), the P-CSCF sets the IMS-Content-Type AVP with the value "CONFERENCE".

– Otherwise, the P-CSCF sets the IMS-Content-Type AVP with the value "NO_CONTENT_DETAIL".

The IMS-Content-Identifier AVP contains information that identifies a particular IMS communication service or a particular communication dialogue in the IMS session. This information may be used by the PCRF to apply different charging characteristics to the different parties in a 3PTY conference scenario.

As a network option, if VBCLTE feature is further supported, the P-CSCF shall be able to indicate to the PCRF caller and callee information.

During AF session establishment, the P-CSCF may include the Calling-Party-Address AVP and the Callee-Information AVP in the AAR command towards the PCRF. The PCRF derives the PCC rules including the information of caller and callee.

During AF session modification, the P-CSCF may include the Callee-Information AVP in the AAR command towards the PCRF. The PCRF updates the PCC rules to categorise the service data flows by rating group or combination of rating group and service id.

The Calling-Party-Address AVP indicates the caller of the IMS service. The P-CSCF determines the caller as defined in clause 7.2.33 of 3GPP TS 32.299 [24].

The Callee-Information AVP indicates the callee of the IMS service. The P-CSCF determines the callee as follows:

– The Called-Party-Address holds the address of the party (Public User ID or Public Service ID) to whom the SIP transaction is posted in the context of an end-to-end SIP transaction as defined in clause 7.2.32 in 3GPP TS 32.299 [24].

– The Requested-Party-Address holds the address of the party (Public User ID or Public Service ID) to whom the SIP transaction was originally posted as defined in clause 7.2.176 in 3GPP TS 32.299 [24].

NOTE: This AVP is only applicable when the ATCF is collocated with the P-CSCF.

– The Called-Asserted-Identity holds the address or addresses (SIP URI and/or Tel URI) of the party (Public User ID or Public Service ID) of the finally asserted called party as defined in clause 7.2.31 of 3GPP TS 32.299 [24].