2. The Internet and OSI Model

Question 1

What is ARPANET, and why is it significant?

Answer 1

ARPANET was the first operational packet-switched network, laying the foundation for the modern internet.

Question 2

Name the seven layers of the OSI model.

Answer 2

Physical, Data Link, Network, Transport, Session, Presentation, and Application layers.

Question 3

What are the differences between the OSI model and the TCP/IP model?

Answer 3

• OSI has seven theoretical layers, while TCP/IP has five practical layers.
• TCP/IP combines the Application, Presentation, and Session layers into a single layer.

Question 4

What layer of the OSI model is responsible for ensuring reliable transmission of data?

Answer 4

The Transport layer, which manages segmentation, acknowledgments, and retransmissions.

Question 5

What is the primary function of the Physical layer in the OSI model?

Answer 5

It transmits raw bits as signals over the physical medium, such as cables or wireless signals.

Question 6

How does the Presentation layer ensure data is readable by the receiving device?

Answer 6

By handling data formatting, encryption, and compression, ensuring interoperability between different systems.