The information which can be acquired at the information communication apparatus side is treated as additional information. The information communication apparatus transmits the additional information and packet data, and the information transmission apparatus communicably connected to the information communication apparatus receives the packet data from the information communication apparatus. Conditions on the basis of the additional information to be received are stored in association with process instruction information. A condition which can be satisfied by the additional information received from the information communication apparatus is searched from among the stored conditions. If a condition which can be satisfied by the additional information is present, predetermined feature information of the packet data received from the information communication apparatus is extracted, the packet data is processed on the basis of the process instruction information associated with the condition, and the extracted feature information is stored in association with the process instruction information.