Exactly as described, this counts received packets on this benchmark port that were classified as too big by the hardware. Unlike the jabber counter, which requires a bad FCS as well, a giant packet here can be a clean, well-formed frame that's simply larger than what this port's currently configured frame-size setting permits, which most often traces back to a mismatch between the generator's configured frame size and the reflector's accepted maximum. For example, a generator sending 9000-byte jumbo frames to a reflector entity still configured with a smaller frame-size limit would show giants accumulating on the reflector side even though the frames themselves aren't corrupted.