2: OSI Model

Question 2

What is the primary purpose of the Open Systems Interconnection (OSI) model?

Answer 2

The OSI model is a conceptual framework used to describe the process that data takes as it traverses a network, providing a standardized way to discuss network functions.

Question 3

What conceptual framework is used to describe the process that data takes as it traverses a network?

Answer 3

The Open Systems Interconnection (OSI) model.

Question 4

What are the seven layers of the OSI model, from Layer 7 down to Layer 1?

Answer 4

Layer 7: Application
Layer 6: Presentation
Layer 5: Session
Layer 4: Transport
Layer 3: Network
Layer 2: Data Link
Layer 1: Physical

Question 5

What is a common mnemonic for remembering the OSI layers from top (Layer 7) to bottom (Layer 1)?

Answer 5

All People Seem To Need Data Processing.

Question 6

What does the Physical Layer (Layer 1) of the OSI model describe?

Answer 6

It describes the physical signals that are sent through the cables, fibers, and wireless transmissions on a network.

Question 7

Which OSI layer describes the physical signals sent through cables, fibers, and wireless transmissions?

Answer 7

The Physical Layer (Layer 1).

Question 8

What are common examples of components that operate at Layer 1?

Answer 8

Cables (copper), fiber optic connections, and wireless radio signals.

Question 9

If you suspect a bad cable or wireless interference, which OSI layer are you troubleshooting?

Answer 9

Layer 1, the Physical Layer.

Question 10

What is the fundamental function of the Data Link Layer (Layer 2)?

Answer 10

It is the fundamental layer used for communication between two devices on the same local network.

Question 11

Which OSI layer is used for communication between two devices on the same local network, often called the ‘switching layer’?

Answer 11

The Data Link Layer (Layer 2).

Question 12

What specific type of hardware address is used at Layer 2 for communication on a local network?

Answer 12

The Media Access Control (MAC) address.

Question 13

What does MAC stand for?

Answer 13

Media Access Control.

Question 14

What is the acronym for Media Access Control?

Answer 14

MAC.

Question 15

What common network device makes its forwarding decisions based on Layer 2 information?

Answer 15

A network switch.

Question 16

What is the primary function of the Network Layer (Layer 3), often referred to as the ‘routing layer’?

Answer 16

The Network Layer is responsible for forwarding traffic between different networks.

Question 17

Which OSI layer is responsible for forwarding traffic between different networks using logical addresses?

Answer 17

The Network Layer (Layer 3).

Question 18

What logical address does a router use at Layer 3 to determine how to forward traffic?

Answer 18

The destination IP address.

Question 19

What is the name for the process of breaking frames into smaller pieces to traverse a network, which occurs at Layer 3?

Answer 19

Fragmentation.

Question 20

What is the main responsibility of the Transport Layer (Layer 4)?

Answer 20

The Transport Layer provides the mechanisms for transporting data between devices and handles the end-to-end management of the connection.

Question 21

Which OSI layer, known as the ‘post office layer,’ manages the end-to-end transportation of data?

Answer 21

The Transport Layer (Layer 4).

Question 22

What are the two primary protocols that operate at the Transport Layer?

Answer 22

Transmission Control Protocol (TCP)
User Datagram Protocol (UDP)

Question 23

What does TCP stand for?

Answer 23

Transmission Control Protocol.

Question 24

What is the acronym for Transmission Control Protocol?

Answer 24

TCP.

Question 25

What does UDP stand for?

Answer 25

User Datagram Protocol.

Question 26

What is the acronym for User Datagram Protocol?

Answer 26

UDP.

Question 27

What is the primary role of the Session Layer (Layer 5)?

Answer 27

The Session Layer is responsible for communication management between devices, including initiating, maintaining, and terminating the session.

Question 28

Which OSI layer is responsible for initiating, maintaining, and terminating communication dialogues?

Answer 28

The Session Layer (Layer 5).

Question 29

What three actions related to a communication dialogue are managed by Layer 5?

Answer 29

The initiation, stopping, and restarting of the session.

Question 30

What is the main function of the Presentation Layer (Layer 6)?

Answer 30

It is responsible for translating data into a format that the Application Layer can understand, such as handling character encoding and encryption.

Question 31

Which OSI layer translates data into a common format, handling tasks like character encoding and application-level encryption?

Answer 31

The Presentation Layer (Layer 6).

Question 32

What common security process, often using SSL or TLS, is associated with Layer 6?

Answer 32

Application-level encryption and decryption.

Question 33

What is the function of the Application Layer (Layer 7) in the OSI model?

Answer 33

It is the top layer that the end-user directly interacts with, providing the interface between applications and the underlying network.

Question 34

Which OSI layer provides the interface that a user sees on their screen?

Answer 34

The Application Layer (Layer 7).

Question 35

Name three common application protocols that operate at Layer 7.

Answer 35

Hypertext Transfer Protocol (HTTP) File Transfer Protocol (FTP) Domain Name System (DNS)

Question 36

Which OSI layer are you interacting with when you view a website in your browser?

Answer 36

The Application Layer (Layer 7).