A method is disclosed for processing multiple, simultaneous incoming calls directed to a single communication device. The method includes receiving, by a proxy server associated with a called communication device, an invitation for each incoming call directed to the called communication device. The method also includes determining, by the proxy server upon receipt of each invitation, the availability of the called communication device by suspending transmission of each invitation and by sending to the called communication device an associated call initiation message for each invitation. The associated call initiation message is free of a Session Description Payload (SDP). The method further includes receiving, by the proxy server, at least one answer message from the called communication device, each answer message being associated with a selected incoming call.