Systems and methods, for an in-band communication channel in an optical network, include adapting one or more client signals into a line signal for transmission to the second node, and utilizing line adaptation bandwidth of the line signal for the in-band communication channel. The in-band communication channel is operationally independent from the one or more client signals while concurrently being transported together over the line signal. The line adaptation allows a rate of the line signal to be independent of rates of the one or more client signals.