Data Communication MCQs with Answers
Practice important Data Communication MCQs with answers and explanations.
Chapter: 153
Q2221:
What is the purpose of bit unstuffing?
A. To compress the frame
B. To remove the stuffed bits at the receiver end
C. To encrypt the data
D. To add error control
Correct Answer:
B
Chapter: 153
Q2222:
Which of the following protocols commonly uses bit stuffing?
A. TCP
B. HTTP
C. PPP
D. IP
Correct Answer:
C
Chapter: 153
Q2223:
What happens if the pattern 01111110 appears within the data portion of a bit-oriented frame?
A. It is ignored
B. The frame is discarded
C. Bit stuffing is used to modify the pattern
D. Frame ends
Correct Answer:
C
Chapter: 153
Q2224:
Why is 01111110 used as a flag in bit-oriented protocols?
A. It's easy to remember
B. It's the only pattern with seven 1s
C. It's unlikely to appear in data naturally
D. It marks the end of a frame
Correct Answer:
D
Chapter: 153
Q2225:
Which technique ensures that the special flag pattern does not accidentally appear in user data?
A. Encryption
B. Checksum validation
C. Byte stuffing
D. Bit stuffing
Correct Answer:
D
Chapter: 153
Q2226:
Fill in the blank: In bit-oriented protocols, the process of removing added bits is known as _______.
A. deframing
B. decoding
C. bit unstuffing
D. unpacking
Correct Answer:
C
Chapter: 154
Q2227:
What is one of the main responsibilities of the data-link control sublayer?
A. Error detection only
B. Flow and error control
C. Encryption and decryption
D. Network routing
Correct Answer:
B
Chapter: 154
Q2228:
Fill in the blank: Flow control maintains a balance between _______.
A. transmission speed and bandwidth
B. production and consumption rates
C. hardware and software utilization
D. memory and disk access
Correct Answer:
B
Chapter: 154
Q2229:
What happens if frames are produced faster than they are consumed at the receiver end?
A. They are stored for later use
B. They are rerouted
C. They are discarded
D. They are acknowledged
Correct Answer:
C
Chapter: 154
Q2230:
Which mechanism is used to temporarily store frames when the receiver is not ready?
A. Flag bits
B. Headers
C. Buffers
D. Checksums
Correct Answer:
C
Chapter: 154
Q2231:
Why do we use buffers in flow control?
A. To speed up transmission
B. To avoid frame loss due to overflow
C. To encode data packets
D. To encrypt transmission
Correct Answer:
B
Chapter: 154
Q2232:
When should consumers communicate with producers in a flow-controlled system?
A. When link is down
B. When the data is corrupted
C. When the buffer is full or has vacancies
D. When acknowledgment is delayed
Correct Answer:
C
Chapter: 154
Q2233:
Fill in the blank: Communication becomes easier if the buffer has only _______.
A. two sections
B. multiple pages
C. one slot
D. three channels
Correct Answer:
C
Chapter: 154
Q2234:
What is the effect of an overfilled buffer at the receiver?
A. The receiver slows down
B. The sender receives an ACK
C. Frames are discarded
D. All frames are stored in secondary memory
Correct Answer:
C
Chapter: 154
Q2235:
Which of the following is true about flow control in data link layer?
A. It only applies to wireless networks
B. It is used to detect errors
C. It ensures sender matches receiver’s processing rate
D. It compresses the data stream
Correct Answer:
C
Chapter: 154
Q2236:
What helps maintain the rate of transmission and reception in flow control?
A. Error codes
B. Buffering
C. Data segmentation
D. Parity check
Correct Answer:
B
Chapter: 154
Q2237:
Which of the following best represents a scenario requiring flow control?
A. Data received before previous data is processed
B. A message is encrypted
C. Packet header is damaged
D. Data is rerouted
Correct Answer:
A
Chapter: 154
Q2238:
Fill in the blank: Flow control prevents _______ at the receiver end.
A. buffer underrun
B. buffer overflow
C. address resolution
D. protocol mismatches
Correct Answer:
B
Chapter: 155
Q2239:
What does CRC stand for in data communication?
A. Cyclic Redundancy Code
B. Central Routing Code
C. Code Repetition Check
D. Connection Retry Control
Correct Answer:
A
Chapter: 155
Q2240:
In error control, what happens if a frame is found to be corrupted?
A. It is corrected and sent back
B. It is acknowledged
C. It is silently discarded
D. It is retried automatically
Correct Answer:
C