A method of determining link topology of a system of active optical cables, wherein each of the active optical cables includes channels and each of the channels includes a light source, a photodetector optically connected to the light source, and a transimpedance amplifier connected to an output of the photodetector, wherein the transimpedance amplifier squelches its output when optical power detected by the photodetector is below a threshold optical power, the method comprising:
- selecting a pattern of optical powers of the light sources in a transmitter to be either above the threshold optical power or below the threshold optical power;
- and
- determining which receiver is connected to the transmitter by matching a pattern of squelched and non-squelched transimpedance amplifier outputs in the receiver with the pattern of optical power of the light sources in the transmitter.