Patent ID: 7035539

Claim:
A sub-network of an optical communication network, the sub-network comprising: four nodes each having two input ports and two output ports; a first one of the nodes having the input ports and one of the output ports coupled to other ones of the nodes, and wherein the other output port of the first node is operable to send signals outside of the sub-network; a second one of the nodes having the output ports and one of the input ports coupled to other ones of the nodes, and wherein the other input port of the second node is operable to receive signals from outside of the sub-network; a third one of the nodes having the output ports and one of the input ports coupled to other ones of the nodes, and wherein the other input port of the third node is operable to receive signals from outside of the sub-network; and a fourth one of the nodes having the input ports and one of the output ports coupled to other ones of the nodes, and wherein the other output port of the fourth node is operable to send signals outside of the sub-network; wherein each of the nodes is operable to: receive a packet comprising a destination address; determine an output port from the sub-network based on the destination address; and route the packet to one of the first node and the fourth node corresponding to the determined output port.