4.2 Interfaces defined for an IM‑SSF based Application Server
23.2783GPPCustomised Applications for Mobile network Enhanced Logic (CAMEL) Phase 4IM CN InterworkingRelease 17Stage 2TS
4.2.1 CSCF – IM‑SSF interface
This interface is the IP Multimedia Service Control interface (ISC). This interface shall be based on SIP as detailed in 3GPP TS 24.229 [8].
4.2.2 IM‑SSF – gsmSCF interface
This interface is used by the gsmSCF to control an IP Multimedia session in a certain IM‑SSF. Relationships between the IM‑SSF and the gsmSCF on this interface are opened as a result of the IM‑SSF sending a request for instructions to the gsmSCF. This interface shall be based on 3GPP TS 29.278 [11].
4.2.3 HSS – IM-SSF interface
This interface is the Si interface and is used to send CAMEL related subscriber data to the IM-SSF, e.g. IM-CSI. This interface shall be a MAP interface as described in 3GPP TS 29.002 [9].