A communication terminal includes a display control unit configured to display, on a display unit, a function selecting screen that contains a first icon for receiving a selection of a first communication function and a second icon for receiving a selection of a second communication function. The first communication function is to provide communication using a signaling protocol for connecting to or disconnecting from a destination of communication and an encoding protocol for encapsulating communication data in IP packets. The second communication function is to provide communication using the same signaling protocol and a different encoding protocol. The communication terminal also includes a receiving unit configured to receive a selection of the first icon or the second icon; and a starting unit configured to start the first communication function and the second communication function in response to the selection of the first icon and the second icon, respectively.