P-CSCF
proxy-call session control function
An IMS SIP server that is the first point of contact in a VoLTE call. The P-CSCF has the following functions:
-
forwards SIP messages to other IMS nodes and to the UE
-
interacts with the PCRF for billing and policy rules
-
maintains a security association with the UE
-
detects and forwards emergency calls to the local E-CSCF