ApplicationLayerI

Question 1

What is the purpose of the Application Layer?

Answer 1

It provides network services directly to user applications, such as email, file transfer, and web browsing.

Question 2

Explain the client-server model.

Answer 2

A client requests services from a server, which provides responses. Clients initiate communication, servers wait for incoming requests.

Question 3

What is a peer-to-peer system?

Answer 3

A system where nodes act as both clients and servers, sharing resources directly without centralized control.

Question 4

How does HTTP operate at the application layer?

Answer 4

HTTP is a stateless protocol used for web communication. It uses TCP for reliable delivery, with non-persistent or persistent connections.

Question 5

Difference between persistent and non-persistent HTTP.

Answer 5

Non-persistent HTTP opens a new TCP connection for each object. Persistent HTTP reuses a single TCP connection for multiple objects.

Question 6

Explain the role of a socket in network communication.

Answer 6

A socket is an endpoint for sending or receiving data across a network. It combines an IP address and port number.

Question 7

What does DNS provide in networking?

Answer 7

DNS (Domain Name System) translates human-readable domain names into IP addresses used for network routing.

Question 8

What happens when a URL is entered into a browser?

Answer 8

Browser queries DNS for IP, establishes TCP connection to server, sends HTTP request, and receives HTTP response to display content.

Question 9

Describe SMTP protocol.

Answer 9

Simple Mail Transfer Protocol (SMTP) is used to send emails between mail servers. It uses TCP for reliable transmission.

Question 10

What are POP3 and IMAP used for?

Answer 10

They are email retrieval protocols. POP3 downloads and deletes messages from server, IMAP allows managing emails directly on the server.