Patent 7502380 was granted and assigned to Hitachi on March, 2009 by the United States Patent and Trademark Office.
A packet handler includes an interface circuit corresponding in one-to-one relation to each input/output port of a switch. A switch interface including a disconnection circuit and a distribution circuit controls the packet from each interface circuit to a corresponding input port and the packet from the output ports of the switch to each interface circuit. In a set of interface circuits, one redundant transmission path can be replaced arbitrarily with two non-redundant independent transmission paths. The packet communication system can thus accommodate redundant transmission paths and non-redundant transmission paths in an arbitrary ratio.