Answer:
Many network and communication protocols require bit stuffing for the following purposes: to avoid the interpretation of data as control information. For example, with six consecutive 1 bits, X.25 uses the bit stuffing,signal the beginning and end of a frame.
High-level Data link control (HDLC) is a bit-oriented protocol for point-to-point and multi-point communication.P/F bits are present in HDLC control field.
So,Yes bit stuffing is necessary in control field.
