In an IP telephone terminal, a function implementation controlling unit is configured so as to be capable of controlling implementation of a function instructed by a file received via IP telephone communications when the communicating unit receives the file. The configuration data storing unit stores configuration data that is used by the function implementation controlling unit to implement the function. The configuration data acquisition controlling unit performs control to acquire configuration data from the configuration data storing unit when a communicating unit receives a read file that is transmitted from an external IP telephone terminal. The response file generation controlling unit performs control to generate a response file including the configuration data. The response file transmission controlling unit controls a communicating unit to transmit the response file to the external IP telephone terminal that has transmitted the read file. The update controlling unit performs, when the communicating unit receives a write file, control to update the configuration data based on the write file that is transmitted from the external IP telephone terminal that has received the response file.