Link Layer

Question 1

What does the link layer do

Answer 1

Transports data grams from one node to another adjacent node using a combination of software and hardware

Question 2

What are the three things that the link layer provides

Answer 2

Flow control: controlling flow between adjacent sending and receiving nodes

Error detection and correction: receiver detects and corrects bit errors without having to retransmit

Half duplex and full duplex:
With Half duplex, nodes at both ends can transmit but not at the same time

Question 3

What is parity?

Answer 3

A method of error detection is to add a parity bit every
d bits. On the receiver side, the number of bits in every block of size d is counted and compared with the adjacent parity bit.

This method can only detect when an even number of bits gets flipped, and even then it can only detect errors, not correct them.

The cost of this method is one extra bit for every
d bits.

Question 4

What does NIC stand for

Answer 4

Network interface card