Figure11.4 Bit stt4 fing and unstuffing透明的比特位填充和移除达 Data from upper layer 0001111111001111101000 Stuffed Frame sent Flag Header 000111110110011111001000 Trailer Flag Extra 2 bits Frame received Flag Header 000111110110011111001000 Trailer Flag Unstuffed 0001111111001111101000 Data to upper layer 11.9 11.9 Figure 11.4 Bit stuffing and unstuffing 透明的比特位填充和移除过程