4 - Data Link Control

Question 1

What is byte stuffing?

Answer 1

The process of adding 1 extra byte whenever there is a flag or escape character in the text.

Question 2

What is bit stuffing?

Answer 2

Adding one extra 0 when five consecutive 1s appear in the data.

Question 3

What is bit unstuffing?

Answer 3

If five consecutive 1s are followed by a 0, the receiver unstuffs the 0 bit.

Question 4

What is flow control?

Answer 4

Refers to a set of procedures used to restrict the amount of data that the sender can send before waiting for acknowledgement.

Question 5

What is error control?

Answer 5

Based on automatic repeat request, retransmission of data.

Question 6

What are the two protocols used for noiseless channels?

Answer 6

Simplest and Stop-and-Wait.

Question 7

What are the three protocols used for noisy channels?

Answer 7

• Stop-and-Wait ARQ
• Go-Back-N ARQ
• Selective Repeat ARQ

Question 8

What is the send window?

Answer 8

An abstract concept defining an imaginary box of size 2^m - 1 with three variables: Sf, Sn, and Ssize

Question 9

Which is more efficient between Go-Back-N and selective repeat ARQ?

Answer 9

Go-Back-N is more efficient when all transmissions are successful, Selective Repeat ARQ is more successful when there is a large probability of errors