Communication network

A master station 11 produces a token packet for isochronous data in which a slave station 12 and slave stations 13 and 14 serving as a sending station and receiving stations are designated using IDs for isochronous data "#2" and "#3" in accordance with contents described in a table 161 held in its inner part so as to manage a transmission bandwidth using a token packet sending/analysis executing device 16, and sends out the produced token packet to a transition path 15 on the downstream side. The slave station 12 sends out an isochronous data packet 42 using the token packet for isochronous data 41. According to the token packet for isochronous data 41, the slave stations 13 and 14 are designated as receiving stations using the ID for isochronous data "#3", so that the slave stations 13 and 14 perform the above-mentioned operations, to receive the isochronous data packet 42. The sending station can thus transmit the same isochronous data to a plurality of receiving stations belonging to a broadcast group, so that it is possible to establish multicast communication (communication to a plurality of nodes).