A CPU executes a process for obtaining, from an ENUM server, a NAPTR record of a destination IP terminal by controlling an IP network controller when placing a call to the destination IP terminal, a process for determining whether the destination IP terminal has at least one communication function corresponding to the source IP terminal based upon the communication functions specified in the NAPTR record and a process for displaying, on a display, the at least one communication function that is determined to be stored in the destination IP terminal.