disclosed herewith is a network that can connect as many vpns as possible to itself . in order to realize such a network , in the frame transfer method of the present invention , which enables a transfer path to be formed between nodes in the network so as to transfer frames , a terminal for transmitting frames or node located outside the transfer path , upon transmitting a frame through the transfer path , writes the transfer path selection information related to the transfer path and the output line information related to the output line from the terminating node of the transfer path in the frame according to the destination information set in the frame and transmits the frame to the destination . the starting node of the transfer path decides the transfer path used for transferring the frame according to the transfer path selection information set in the frame to transmit the frame while the terminating node of the transfer path decides the output line used to output the frame therefrom according to the output line set in the frame , thereby transmitting the frame to the output line .