Fundamentals of Computer Networks (Part 1)

Twenty question-and-answer flashcards reviewing key concepts from the Fundamentals of Computer Networks lecture.

What is a computer network?

A system of two or more computers connected by a transmission medium for the exchange of data.

What defines a Local Area Network (LAN)?

A network covering a small geographical area (e.g., one building) that offers high data transfer speeds and easy resource sharing.

How large is a Metropolitan Area Network (MAN)?

It spans multiple buildings within the same town or city, larger than a LAN but smaller than a WAN.

What distinguishes a Wide Area Network (WAN) from a LAN?

A WAN covers large geographical areas, connects multiple LANs/MANs, and uses long-range transmission media such as fiber, telephone lines, or satellites.

Who can access an intranet versus the Internet?

An intranet is restricted to authorized users within an organization, whereas the Internet is a public network accessible globally.

How does a network switch improve on a hub?

A switch forwards packets only to the intended device using MAC addresses, reducing congestion, while a hub broadcasts packets to all connected devices.

What are the two main functions of a router?

Connecting multiple networks and determining the most efficient route for data packets using routing protocols.

What job does a modem perform in a network?

It modulates digital signals to analog for transmission and demodulates incoming analog signals back to digital.

What unique hardware identifier is embedded in every NIC?

A 48-bit Media Access Control (MAC) address.

How do MAC addresses differ from IP addresses?

MAC addresses identify hardware on a local network permanently, while IP addresses identify logical connections and can change or be reassigned.

What is the primary purpose of the Domain Name Service (DNS)?

Translating human-readable domain names into IP addresses through a hierarchical, distributed database.

List the five layers of the TCP/IP model from top to bottom.

Application, Transport, Internet, Link (Data-Link), Physical.

How does TCP differ from UDP at the Transport layer?

TCP provides reliable, connection-oriented delivery with acknowledgements; UDP offers faster, connectionless delivery without guaranteed reliability.

Which TCP/IP layer routes data packets across different networks?

The Internet layer, primarily using the Internet Protocol (IP).

What is packet switching?

A method that breaks data into packets sent independently through the network, allowing shared, on-demand use of bandwidth.

What is the function of the Time To Live (TTL) field in an IP packet header?

It limits a packet's lifespan by decrementing at each router hop; when TTL reaches zero, the packet is discarded to prevent infinite looping.

Why do routers maintain routing tables?

To store information about known networks and determine the best next hop for forwarding packets toward their destinations.

Why is packet switching generally more efficient than circuit switching for bursty data?

Because bandwidth is allocated only when packets are transmitted, avoiding unused dedicated circuits and improving overall link utilization.

Which protocol sends email from a client to an email server?

Simple Mail Transfer Protocol (SMTP).

Which link-layer protocol encapsulates data into frames with source and destination MAC addresses?

The Ethernet protocol (also applicable to Wi-Fi at the Data-Link layer).