An MPOA system for establishing communication by using layer 3 protocol on an ATM network, in which data about the layer 3 address of a source of data packets is added to an address resolution request packet which is transmitted in order to establish a shortcut VCC toward a destination of the data packets in each communication node and hence transmitted to the destination, and in the case of accepting the address resolution request packets to be transmitted in order to establish the respective shortcut VCCs toward the destination of the data packets, as for the same communication, from a plurality of the communication nodes, a shortcut VCC is established only between the destination and the communication node remotest from the destination on the network.