Computer Networks Lecture 10: Data Link Layer

What mechanism for error detection involves appending a redundant bit to every data unit to make the total number of 1s in the unit even?

Simple Parity Checking

Which sublayer of the data link layer is responsible for hardware addressing mechanism and controlling physical media access?

Media Access Control (MAC)

What is the term used to describe an error where two or more bits in the data unit have changed from 0 to 1 or vice-versa, without necessarily occurring in consecutive bits?

Burst Error

Which data link layer protocol is commonly used for wireless links?

802.11 Signup and view all the answers

Which error detection mechanism organizes the block of bits in a table and calculates parity check bits for each row and column to not only detect but also correct errors?

Two-dimensions Parity Check Signup and view all the answers

What is the responsibility of the data link layer?

Transferring datagram from one node to physically adjacent node over a link Signup and view all the answers

What does the data link layer do with packets from the network layer?

Encapsulates them into frames Signup and view all the answers

Which hardware example illustrates the implementation of the data link layer?

Ethernet card and 802.11 card Signup and view all the answers

What is the primary function of the data link layer?

Framing Signup and view all the answers

How does the data link layer transfer frames on the hardware?

Bit-by-bit Signup and view all the answers

What is the responsibility of the data link layer in a computer network?

Transferring datagram from one node to the physically adjacent node over a link by converting data stream to signals bit by bit and sending them over the underlying hardware. Signup and view all the answers

How does the data link layer handle datagrams at the adjacent node?

The data link layer picks up data from the hardware, assembles them into a recognizable frame format, and hands them over to the upper layer. Signup and view all the answers

What is the function of framing in the data-link layer?

Encapsulating packets from the network layer into frames and sending each frame bit-by-bit on the hardware. Signup and view all the answers

Give an example of the implementation of the data link layer in hardware.

Ethernet card and 802.11 card Signup and view all the answers

What is the primary purpose of data link layer protocols in a computer network?

To transfer datagrams by different link protocols over different links, such as Ethernet on one link and 802.11 on another link. Signup and view all the answers

What are the two sub-layers of the data link layer, and what are their respective functions?

Logical Link Control (LLC) and Media Access Control (MAC). LLC deals with framing, flow control, error detection, and correction. MAC is responsible for hardware addressing and controls physical media access. Signup and view all the answers

Explain the difference between single-bit error and burst error in data transmission.

Single-bit error means that only one bit of a data unit is changed, while burst error means that two or more bits in the data unit have changed, not necessarily in consecutive bits. Signup and view all the answers

What is the primary purpose of the Cyclic Redundancy Check (CRC) mechanism in error detection?

The primary purpose of CRC is to detect errors in transmitted data. Signup and view all the answers

How does the simple parity check mechanism improve error detection?

The simple parity check appends a redundant bit to every data unit to ensure that the total number of 1s in the unit, including the parity bit, is even. Signup and view all the answers

What types of errors are addressed by the Error Control function of the data link layer, and how are these errors handled?

Error Control handles errors caused by signal attenuation, noise, and bit flips. These errors are detected and attempted to be recovered through error detection and correction mechanisms. Signup and view all the answers