A method and apparatus for performing a handover are disclosed. An Internet protocol (IP) multimedia subsystem (IMS) client registers with an IMS network and establishes a media independent handover (MIH) session with an MIH application server using a session initiation protocol (SIP). The IMS client establishes a session for IP-based service, (e.g., voice over IP (VoIP)), with a communication peer using an SIP. MIH messages are exchanged for handover with the MIH application server over IP. After handover, the session is resumed. A serving call session control function (S-CSCF) triggers the MIH application server based on a string "MIH services" and a unique identifier included in an INVITE request. The IMS client may send a REFER request to the MIH application server after the handover to resume the session. Alternatively, the IMS client may send a RE-INVITE request to the MIH application server and the communication peer.