IP MULTIMEDIA SUBSYSTEM, PROXY SESSION CONTROL APPARATUS, AND COMMUNICATION CONTROL METHOD

摘要

A P-CSCF (310) includes a terminating call processing unit (311) which receives SIP INVITE from an S-CSCF. The SIP INVITE includes an identifier of UE, and is relayed in response to acceptance of a terminating call to the UE. The P-CSCF (310) further includes: a restoration execution unit (313) which executes restoration of a subscriber profile linked with the UE based on reception of the SIP INVITE; and an address holding unit (315) which holds an address of a PCRF included in a response received from a DRA along with the execution of the restoration. The restoration execution unit reestablishes a session between the UE and the PCRF based on the held address of the PCRF, and causes the UE to execute re-registration with an IP multimedia subsystem.