Patent ID: 7321938

Claim:
A data transfer apparatus for connecting a plurality of buses and for transmitting data through a first bus to a second bus according to destination information related to the data, the data transfer apparatus being connected to the second bus through a second data transfer apparatus, the data transfer apparatus comprising: transferring means for transferring the data from the data transfer apparatus to the second data transfer apparatus according to the destination information; determining means for determining, according to the destination information, whether a node serving as a destination of the data is connected to the second bus; wherein, when the determining means determines that the node is not connected, a data transmission source receives a predetermined error information signal, wherein the predetermined error information signal prevents retransmission; wherein at least one packet of the data, transmitted to the node that is not connected, is processed as an error packet; wherein the destination information comprises a node ID and a bus ID; and wherein the data transfer apparatus is formed of an IEEE-1394 bridge conforming to the BRAIN specification.