Figure1l.2 Byte stuffing and unstuffing字节填充和移除 Data from upper layer Flag ESC Frame sent Stuffed Flag Header ESC Flag ESC ESC Trailer Flag Extra 2 bytes Frame received Flag Header ESC Flag ESC ESC Trailer Flag Unstuffed Flag ESC Data to upper layer 11.5 11.5 Figure 11.2 Byte stuffing and unstuffing 字节填充和移除