PURPOSE: To ensure repetition by monitoring the plural groups of information received from an LAN, and transmitting the information groups to a WAN(wide area network) successively from the information group whose priority is high.

CONSTITUTION: A between-LAN/WAN connector R2 which connects the LAN with the WAN being the other LAN connected through a public network is equipped with a packet monitoring part 24 being an information monitoring means which monitors a packet received from the LAN. The packet monitoring part 24 validates a packet repetition processing according to the priority at the time of network congestion by setting the priority for each classification of the packet by a user. Therefore, even at the time of the network congestion, the transmission can be ensured by setting the priority of the important data high. Then, when the network congestion is not detected, the rearrangement of the packets is not operated, so that the conventional data repetition processing can be attained.