A method may include receiving, at an application server, a session initiation protocol (SIP) message including a public user identifier (ID) associated a user. The public user ID corresponds to a plurality of user devices. The method also includes determining an applicable order of alerting at least one of the plurality of user devices. The method further includes identifying at least one available user device associated with the user, based on a terminal identifier (ID) associated with each at least one available user device. The method also includes selecting a user device from the at least one available user device based on the applicable order of alerting. A SIP invite message, including a terminal ID for the selected user device, is generated. The method includes sending the SIP invite message to the selected user device based on the applicable order of alerting, and receiving a response to the SIP invite message.