Lecture 5

Question 1

What is a LAN?

Answer 1

Local area network (LAN)
Two or more computers connected together within a small geographical area
LANs can only transmit data very fast but only over a short distance

Question 2

What is a MAN?

Answer 2

Metropolitan area network (MAN)

A network spanning a local community

Question 3

What is a WAN?

Answer 3

Wide area network (WAN)

WANs are typically spread across a large geographical are and relies on third party carries or communications

Question 4

Types of topologies?

Answer 4

Topology (configuration)
Bus 
– Ethernet
Star 
     – Wireless networks with central Access Point (AP)

Question 5

What are protocols?

Answer 5

Defines a set of rules required for data communication between devices
To govern transmission of data

Question 6

What is the CSMA/CD protocol?

Answer 6

Carrier Sense, Multiple Access with Collision Detection
Used in Ethernet
Silent bus provides right to introduce new message only when the media is not being used

Question 7

What is the CSMA/CA protocol?

Answer 7

Carrier Sense, Multiple Access with Collision Avoidance
Used in WiFi
A computer signals its intention to transmit before it actually transmits data. In this way, computers will sense when a collision might occur avoiding transmission collisions. broadcasting intention to transmit data increases the amount of traffic on the cable and slows down network performance.
A newcomer is not allowed to claim a silent channel until any machine that has been waiting is given the opportunity to start

Question 8

What is the hidden terminal Problem?

Answer 8

Occurs when a node is visible from a wireless access point (AP), but not from other nodes communicating with that AP. This leads to difficulties in media access control sublayer (concerned with sharing the physical connection to the network among several computers.). So nodes cannot detect a collision while transmitting

Question 9

What is a Repeater?

Answer 9

Repeater: Extends a network

Question 10

What is a Bridge?

Answer 10

Bridge: Connects two compatible networks

Question 11

What is a Switch?

Answer 11

Switch: Connects several compatible networks

Question 12

What is a Router?

Answer 12

Router: Connects two incompatible networks, resulting in a network of networks called an internet

Question 13

What is Client-server?

Answer 13

One server, many clients
Server must execute continuously
Client initiates communication
Server must be prepared to serve multiple clients at any time

Question 14

What is Peer-to-peer (P2P)?

Answer 14

Have equal status
each computer on the network acts as both client and server
There is no centralized control

Question 15

What are distributed systems?

Answer 15

Systems with parts that run on different computers

Question 16

What is ISP?

Answer 16

Internet Service Provider (ISP)
Tier-1directly connects with and has access to the global Internet backbone in a specific region
Tier-2 engages in the practice of peering with other networks
Access ISP: Provides connectivity to the Internet
Traditional telephone (dial up connection)
Cable connections
DSL (digital subscriber line, voice and digital data communication)
Wireless

Question 17

What is an IP Address?

Answer 17

An IP address is a unique address that is assigned to a network device
IP address: pattern of 32 (V4) or 128 (V6) bits often represented in dotted decimal notation

Question 18

What is ICANN?

Answer 18

Allocates IP addresses to ISPs who then assign those addresses within their regions.
Oversees the registration of domains and domain names.

Question 19

What is FTP?

Answer 19

File Transfer Protocol (FTP) used to transfer computer files between a client and server on a computer network

Question 20

What is telnet and SSH?

Answer 20

Telnet and SSH (Secure Shell)

The SSH protocol encrypts communication to prevent network eavesdroppers