Patent ID: 7151893

Claim:
A data transmission system comprising: a first network to optically transmit a data signal and a monitor control signal in an optical signal; first and second nodes connecting to the first network; and a second network capable of transmitting an alternate monitor control signal; wherein the first node comprises, a demultiplexer to demultiplex the data signal and the monitor control signal out of the optical signal from the first network; a signal distributor having a plurality of input ports and a plurality of output ports to distribute the data signal demultiplexed by the demultiplexer to a designated one of the plurality of output ports; a controller to control the signal distributor and to monitor each port in the first node; a first selector to select one of the monitor control signal demultiplexed by the demultiplexer and the alternate monitor control signal received from the second network and to apply the selected monitor control signal to the controller; a second selector to output a monitor control signal output for the second node, output from the controller, toward one of the first network and the second network; and a multiplexer to multiplex the monitor control signal output for the first network, output from the second selector, and the data signal output from the signal distributor and to output the multiplexed signals onto the first network.