METHOD OF OBTAINING PROXY CALL SESSION CONTROL FUNCTION ADDRESS WHILE ROAMING

摘要

A method of obtaining Proxy Call Session Control function P-CSCF address while roaming is provided. When terminal accesses IP Multimedia Subsystem IMS by World Interoperability for Microwave Access WIMAX while roaming, Visited Authentication Authorization and accounting server V-AAA of said terminal receives access request message transmitted by Access Service Network ASN or Dynamic Host Configuration Protocol DHCP server or Home Agent HA of said terminal, and retransmits said access request message to Home Authentication Authorization and Accounting server H-AAA of said terminal. Said H-AAA determines whether Proxy Call Session Control Function P-CSCF locates visited network or home network according to roaming protocol and ability of visited network, encapsulates determined P-CSCF address information into access acceptance message corresponding to said access request message and returns said access acceptance message to transmitter of said access request message via V-AAA.