This counter counts frames the port transmitted that already had the FECN bit set before transmission, meaning the port is relaying a congestion notification rather than generating one itself. It helps an administrator confirm that forward congestion signaling from upstream is being propagated correctly to the far end of the circuit. For example, if a downstream site complains of slow performance, the admin would check this counter to see whether FECN markings are indeed reaching that leg of the path.