Exam 1- Fund. of Computer Networks

Chapter 1 & 2

Q: What are the two distinct definitions of the Internet?

A: 1) A network of networks that connects millions of devices worldwide. 2) A platform for applications and services (email, web, social media).

Q: What is a network?

A: A collection of devices (hosts) connected by communication links that exchange data.

Q: What is a protocol?

A: A set of rules governing how data is transmitted and received across a network

Q: What is the network edge?

A: The devices and hosts (like computers, phones, servers) at the boundary of the network.

Q: What are the CIA traits?

A: Confidentiality (only authorized access),  Integrity (data accuracy and trust), Availability (data accessible when needed).

Q: What is encapsulation?

A: The process where each layer of the network adds its own header (and sometimes trailer) to data as it passes downward.

Q: OSI vs TCP/IP: How many layers?

A: OSI = 7 layers; TCP/IP = 5 layers.

Q: Main difference between OSI and TCP/IP?

A: OSI is theoretical and detailed; TCP/IP is practical and based on real-world protocols.

Q: What is an RFC?

A: “Request for Comments”

Q: What is process-to-process communication?

A: Communication between applications running on different end systems,  enabled by transport layer protocols.

Q: Name the four transport layer services.

A: Reliable data transfer, Flow control, Error detection, Multiplexing(send)/demultiplexing(recive).

Q: SMTP vs IMAP – similarity?

A: Both are email-related protocols.

Q: SMTP vs IMAP – key difference?

A: SMTP sends mail, IMAP retrieves and manages mail on the server.

Q: What are the two types of HTTP connections?

A: Persistent and non-persistent.

Q: Advantage of persistent HTTP?

A: Multiple requests over a single connection → less delay.

Q: HTTP is stateless. What solves this?

A: Cookies.

Q: Three uses of cookies?

A: Authentication (login sessions), personalization (user settings), tracking (analytics, ads).

Q: Main benefit of web caching?

A: Reduces response time and server load by storing frequently accessed data closer to users.

Q: How do CDNs solve scalability and heterogeneity

A: By distributing content across many servers worldwide, improving speed and reliability for users everywhere.

Q: HTTP/1.1 vs HTTP/2 vs HTTP/3 – key improvements?

A:HTTP/1.1: Persistent connections. HTTP/2: Multiplexing, faster. HTTP/3: Based on QUIC/UDP, lower latency.