A CR/CMP layer sets up isochronous channels, the number of which is that of data streams to be transferred, and sets channel numbers associated with the isochronous channels in IT packet processing units of IT processing units of bus control LSI units connected to data streams of AV devices. The IT processing units of the bus control LSI units are caused to perform transmission/reception of isochronous packets using isochronous channels having the set channel numbers. The IT packet processing unit of the IT processing unit of each stealth bus control LSI unit sets, in an SID field of the CIP header of an isochronous packet to be transmitted, the node ID of the representative bus control LSI unit instead of its own node ID.