In order to facilitate a handoff of a communication session between a legacy circuit switched network and a packet data network such as a 3GPP LTE, 3GPP2 UMB, or WiMAX network, which communication session is anchored in an IMS Voice Call Continuity Application Server (VCC AS), a Circuit Switched Proxy (CS Proxy) is provided in the packet data network that communicates with a Mobile Switching Center (MSC) of the circuit switched network. The CS Proxy allows the packet data network to communicate with the VCC AS, the MSC to communicate with the packet data network, and the MSC to communicate with the VCC AS via the packet data network, thereby allowing an exchange of handoff-related information between the packet data network and the VCC AS, the packet data network and the circuit switched network, and the circuit switched network and the VCC AS via the packet data network.