SD-FEC defect propagation across regeneration nodes in support of single and multi-carrier super channel protection in ROADM networks

A regen node is described. The regen node includes a coherent receiver, a control module and a coherent transmitter. The coherent receiver has circuitry to convert a first optical signal received from an upstream node in an optical layer of an optical network to a first digital data stream in a digital layer having a first FEC frame and a data traffic. The control module extracts a first fault signal from the first FEC frame; generates a second fault signal based at least in part on the first fault signal; and encodes the second fault signal within a second FEC frame with the data traffic into a second digital data stream on the digital layer. The coherent transmitter has circuitry to convert the second digital data stream into a second optical signal on the optical layer and to transmit the second optical signal to a downstream node.