X.2 Reference points to support SBA in IMS

24.2293GPPIP multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP)Release 18Stage 3TS

The following IMS related reference points are realized by service-based interfaces:

– N5: Reference point between the PCF and an AF.

NOTE 1: The P-CSCF acts as an AF from the PCF point of view. The N5 Reference point is defined in 3GPP TS 23.501 [257] and the related protocol specification is in 3GPP TS 29.514 [273]. It provides equivalent functionality to the Diameter-based Rx reference point.

– N70: Reference point between an SBI capable I/S-CSCF and an SBI capable HSS.

NOTE 2: The N70 Reference point is defined in 3GPP TS 23.501 [257] and the related protocol specification is in 3GPP TS 29.562 [274]. It provides equivalent functionality to the Diameter-based Cx reference point.

– N71: Reference point between an SBI capable IMS AS and an SBI capable HSS.

NOTE 3: The N71 Reference point is defined in 3GPP TS 23.501 [257] and the related protocol specification is in 3GPP TS 29.562 [274]. It provides equivalent functionality to the Diameter-based Sh reference point.