Patent ID: 8453211

Claim:
A method for obtaining a proxy call session control function (P-CSCF) address during roaming, comprising: when a terminal accesses an IP multi-media subsystem (IMS) through a world interoperability for microwave access (WiMAX) network in a roaming scenario, a visited authentication, authorization, and accounting server (V-AAA) of said terminal retransmitting an access request message sent by an access service network (ASN) or a dynamic host configuration protocol (DHCP) server or a home agent (HA) of said terminal to a home authentication, authorization and accounting server (H-AAA) of said terminal after receiving the access request message; and said H-AAA determining whether the P-CSCF is located in a visited network or a home network according to a roaming agreement and visited network capability, and returning the determined P-CSCF address information, which is included by said H-AAA in an access accept message corresponding to said access request message, to the sender of said access request message through said V-AAA.