Patent ID: 8014775

Claim:
A method for implementing IP Multimedia Subsystem (IMS) messaging services, comprising: receiving, by an originating Call Session Control Function (CSCF 1 ), a message body sent by a calling user; forwarding, by the originating CSCF (CSCF 1 ), the message body to an originating Message Application Server (MAS 1 ); determining, by the originating MAS (MAS 1 ), whether the calling user and a called user belong to a same IMS domain according to user registration information, wherein the calling user is a registered user of an IMS domain and the called user is a registered user of an IMS domain; and sending, by the originating MAS (MAS 1 ), the message body to the called user through the originating CSCF (CSCF 1 ) and bypassing a terminating MAS (MAS 2 ) and a terminating CSCF (CSCF 2 ), if the calling user and the called user are in the same IMS domain.