In a network which includes at least a transmission-side apparatus having a plurality of logical plugs and a reception-side apparatus having a plurality of logical plugs, correspondence between transmission-side logical plugs (e.g., P2 to P4) and reception-side logical plugs (e.g., P4 to P6) is established. The reception-side apparatus stores therein plug data Splug (P2) representing one of the transmission-side logical plugs, plug data Dplug representing a logical plug corresponding to the plug data Splug, among the plurality of reception-side logical plugs, and connection number Nconn representing the number of logical plugs to be connected. The transmission-side apparatus adds to control data a plug number PluNO (P3) representing the logical plug which has output the control data and transmits the control data. The reception-side apparatus determines whether to receive the control data, on the basis of PluNO, Splug, and Nconn, and specifies a logical plug (P5) which receives the control data, on the basis of PluNO, Splug, and Dplug.