| 摘要 |
A telecommunications system provides an internet protocol multimedia communications session to a mobile user equipment. The telecommunications system comprises an internet protocol multimedia subsystem operable to provide the internet protocol multimedia communications session to the mobile user equipment, the internet protocol multimedia subsystem including a call state control function, and a roaming mobile application server. The telecommunications system includes a packet radio network operable in response to a packet data protocol context application request from the mobile user equipment providing an access point name for terminating the multi-media communications session, to confirm, using a domain name server whether the access point name identifies one of a gateway support node of the packet radio network or a gateway support node of a home network of the mobile user equipment. The mobile user equipment is operable to communicate a register message to the roaming mobile applications server. The roaming mobile application server is responsive to the register message, to determine whether the access point name, which was used to communicate the register message, corresponds with a preferred access point name for the mobile user equipment. If the access point name does not correspond to the preferred access point name, the roaming mobile application server communicates a re-register message providing the preferred access point name to the mobile user equipment for use in terminating the communications session at a gateway support node identified by the preferred access point name. |
