This counter records how many times the port's receiver had to be turned off, presumably because no receive buffer was available to accept incoming data. A rising count signals that the receive side of the port is being starved of buffer resources, which can lead to dropped or delayed frames. For example, a technician diagnosing intermittent packet loss on a heavily loaded port would check this counter to see whether buffer exhaustion, rather than a wiring or clocking issue, is the cause.