Chapter 6 - Networks

Question 1

Network

Answer 1

Collection of connected computers and their peripherals

Question 2

LAN

Answer 2

Local area network, confined to one site

Question 3

WAN

Answer 3

Wide area network, covers a large geographical area

Question 4

NIC

Answer 4

Network interface cards has a unique MAC number (stored in ROM) for identification and generates electrical signals to allow connection

Question 5

Hubs

Answer 5

Hardware that connects devices making them a network segment. Signals are transmitted to all connected devices

Question 6

Switches

Answer 6

Connect network segments, signals only transmitted to intended device

Question 7

Wireless access points

Answer 7

Allows connection to a LAN without need for cables, usually connected to router

Question 8

Router

Answer 8

Receives data packets which are forwarded to destination, directs traffic through large networks, connects individual computers to the internet

Question 9

Protocols

Answer 9

A set of rules that covers data communication

Question 10

Data packets

Answer 10

Collections of data forming part of a message, sent on a network

Question 11

Archives

Answer 11

Where old data no longer in use is stored

Question 12

Failover

Answer 12

When a system detects a potential disaster and sends operations to a duplicate system

Question 13

HTML

Answer 13

Hypertext markup language, is a text file that allows embedding of many elements and other scripting languages to a web page

Question 14

XML

Answer 14

Extensible markup language allows separation of HTML display code and data (less HTML needed - smalller file size), allows users to create own tags

Question 15

CSS

Answer 15

Cascading Style Sheets, adds design to a web page, stored outside of main HTML

Question 16

Compression

Answer 16

Reducing file size to save storage space or reduce transmission times

Question 17

Lossy compression

Answer 17

Removing less important data from a file which cannot be recovered

Question 18

Lossless compression

Answer 18

Does not store repeated details so files can be reconstructed easily

Question 19

What are advantages of a LAN? (6)

Answer 19

1) Central data storage
2) Easily updated centrally
3) Computer use easily administrated
4) Security policy centrally administrated
5) Users can communicate
6) Peripherals can be shared

Question 20

What are disadvantages of a LAN? (3)

Answer 20

1) Specialist staff may be needed for maintenance
2) Network problems may affect all users
3) Data accessible from many places

Question 21

How can security problems caused by wireless access points be dealt with? (3)

Answer 21

1) Encryption
2) Hiding broadcast identities
3) Allowing access to only some MAC addresses

Question 22

Client-server network

Answer 22

One or more servers provide services to many machines - functions are handled by dedicated machines

Question 23

Servers

Answer 23

Computers that are set up to handle network functions e.g. database, mail, print servers

Question 24

Peer-to-peer netwroks

Answer 24

All computers are equal, each computer meets the needs of a user as well as carrying out network functions - easy to set up, can be used online to share files without going through server

Question 25

What are the disadvantages of peer-to-peer networks? (3)

Answer 25

1) More difficult to maintain 2) Poor security 3) Slow

Question 26

What is bus topology?

Answer 26

Nodes are attached to a single backbone with terminators. This means it is easy and cheap to set up but a problem can bring the whole network down and there are many data collisons - slow

Question 27

What is star topology?

Answer 27

Nodes are connected to a central switch or hub so problems do not affect the whole network and there are few data collisions, but can be expensive, more hardware and software is needed

Question 28

What is ring topology?

Answer 28

Data passes through each node carried in data units called tokens. There are no collisions but problems can bring the whole network down and it is vulnerable to malfunctions

Question 29

What is a host?

Answer 29

Computer systems that are accessed remotely and hold data

Question 30

What is DNS?

Answer 30

An internet protocol - domain name system - that translates domain names into IP addresses

Question 31

What can be included in an acceptable use policy?

Answer 31

Not transmitting offensive material, not using network for marketing, not accessing unauthorised material, not destroying data, not wasting staff time

Question 32

What is a modem?

Answer 32

Modulator-demodulator. Converts between analogue and digital signals

Question 33

Network bridge

Answer 33

Hardware that links networks together

Question 34

Network protocol

Answer 34

Rules and standards for data transfer

Question 35

TCP/IP

Answer 35

TCP - protocols for connection | IP - protocols for data reconstruction

Question 36

Domain name

Answer 36

Identifies resource on internet in human friendly way

Question 37

DSL

Answer 37

Digital subscriber line - uses POTS for internet