Patent ID: 8335201

Claim:
A call control method, comprising: receiving a call request of a calling terminal, wherein the call request carries a called terminal number; querying a Home Location Register (HLR) of a called terminal according to the called terminal number; obtaining a Supplementary Service Code (SS_Code) from the HLR, wherein the SS_Code carries a Mobile Station International ISDN Number (MSISDN)-based IP Multimedia Subsystem (IMS) service identifier; originating, by a Mobile Switching Center (MSC), a call to a Gateway Mobile Switching Center (GMSC) according to the MSISDN-based IMS service identifier; triggering, by the GMSC, an Application (AS) to implement an MSISDN-based IMS service according to the call originated by the MSC; wherein triggering the AS to implement the MSISDN-based IMS service according to the call originated by the MSC comprises: sending, by the GMSC, an MSISDN-based IMS service trigger request to the AS, wherein the MSISDN-based IMS service trigger request carries information about the calling terminal and the called terminal; querying, by the AS, an Internet Protocol (IP) client corresponding to the called terminal according to the information about the called terminal; and connecting, by the AS, the call originated by the calling terminal to the IP client according to the information about the calling terminal; receiving, by the GMSC, a secondary connection request from the AS; obtaining, by the GMSC, a called Mobile Subscriber Roaming Number (MSRN) through a HLR of calling terminal; and connecting, by the GMSC, the call to the called mobile terminal according to the called MSRN.