Patent ID: 7042849

Claim:
A method for controlling data transmission in a network system configured by a plurality of nodes including a first node, a second node, and a third node, wherein the first node has a plurality of ports including a first port connected to the second node and a second port connected to the third node, and wherein each node has address information, the method comprising the steps of: when the first node receives data, the received data including the address information of the node to which the received data is addressed, comparing at the first node the address information stored in the first node with the address information included in the received data; temporarily disconnecting the third node from the first node to form a first sub-network system, which includes the third node and does not include the first node, and a second sub-network system, which includes the first node, when the received data is not addressed to a downstream node including the third node; and permitting data transmission within each of the sub-network systems.