Define the lowest threshold to receive packets from the HSB. This parameter is relevant when the receive buffer is almost full. When the buffer reached this threshold, the only packets that the port will receive will be those with at least middle priority (2) who were already written in the priority machine. All other packets will be rejected. The space between empty2 to empty1 is reserved to packets with at least middle priority (2) who were already written in the priority machine. When the buffer did not reached this lowest priority, no packet will be rejected for empty space. Version 7.0