An optical network is described that has a first ROADM node, a second ROADM node, and an optical transmission line establishing optical communication between the first ROADM node and the second ROADM node. The optical transmission line including an in-line amplifier node having a total input power and a total output power. The in-line amplifier node has a first monitoring tool configured to measure input optical power of the in-line amplifier node, and a second monitoring tool configured to measure output optical power of the in-line amplifier node. A software defined L0 network controller has circuitry configured to receive the optical power measured by the first and second monitoring tools from the in-line amplifier node, and to configure at least one of a gain and a gain tilt of the in-line amplifier node.