This is the highest value recorded during the current performance-monitoring interval of the combined received optical power across all optical lanes of this multi-lane coherent port during the current performance-monitoring interval. The highest combined power seen in the interval confirms the port as a whole isn't being overdriven, which matters because total power, not just any single lane, determines when the receiver's overload protection kicks in. For example, comparing inOpticalPowerLaneTotalMax against the port's rated overload threshold after a span shortening confirms whether an attenuator needs to be added at the port level.