This integer setting specifies whether the fiber connection is bidirectional (twoWay, the default) or carries traffic in only one direction (oneWay). Knowing this matters because a one-way fiber connection entry, such as those used for optical monitoring taps, should not be expected to carry return traffic. An admin configuring span-loss monitoring on a unidirectional tap fiber would set this to oneWay so the system doesn't flag a missing return path as a fault.