A first communication terminal configured to perform wireless communication with a second communication terminal, the first communication terminal comprising: a communication determiner configured to determine whether to perform communication in a long-range wireless communication mode, which is a communication mode for communicating with the second communication terminal by using a server; a communicator configured to, based on the determination, transmit a connection request to the server and receive a response message including authentication information for establishing communication with the second communication terminal from the server; and a controller configured to control the first communication terminal to perform long-range wireless communication with the second communication terminal in response to the response message, wherein the authentication information comprises information regarding a result of authentication determined based on whether the first communication terminal is included in a list of trusted devices of the second communication terminal; wherein the communicator is further configured to: transmit a control signal for controlling a function of the second communication terminal based on a user input via the long-range communication established between the first communication terminal and the second communication terminal, and receive a response message comprising information regarding a result of performing the function of the second communication terminal based on the control signal via the long-range wireless communication, the function including one of a phone call transmitting function to a telephone network and a phone call receiving function from the telephone network. a communication determiner configured to determine whether to perform communication in a long-range wireless communication mode, which is a communication mode for communicating with the second communication terminal by using a server; a communicator configured to, based on the determination, transmit a connection request to the server and receive a response message including authentication information for establishing communication with the second communication terminal from the server; and a controller configured to control the first communication terminal to perform long-range wireless communication with the second communication terminal in response to the response message, wherein the authentication information comprises information regarding a result of authentication determined based on whether the first communication terminal is included in a list of trusted devices of the second communication terminal; wherein the communicator is further configured to: transmit a control signal for controlling a function of the second communication terminal based on a user input via the long-range communication established between the first communication terminal and the second communication terminal, and receive a response message comprising information regarding a result of performing the function of the second communication terminal based on the control signal via the long-range wireless communication, the function including one of a phone call transmitting function to a telephone network and a phone call receiving function from the telephone network. transmit a control signal for controlling a function of the second communication terminal based on a user input via the long-range communication established between the first communication terminal and the second communication terminal, and receive a response message comprising information regarding a result of performing the function of the second communication terminal based on the control signal via the long-range wireless communication, the function including one of a phone call transmitting function to a telephone network and a phone call receiving function from the telephone network.