Ib Computer Science: Topic 3

Front 1

Bus topology

Back 1

Computer network in which a "bus" connects ask devices together through a common cable

Hint 1

Cable: copper wire (usually coaxial and twisted pair) and fibre (fibre optic cable made from glass). Cables allow for the connection of computers over a network.

Front 2

Check digit

Back 2

Extra digit added to numerical data that is used to check data integrity after input, transmission, storage and processing

Front 3

Data integrity

Back 3

The accuracy of data after input, transmission, storage or processing.

Front 4

Check sum

Back 4

Error-detecting procedur that generates a sum from the digits of a number

Front 5

Data packet

Back 5

Portion of a message that is transmitted through a network.

Hint 5

Contains data such as check digits and designation address.

Front 6

Gateway

Back 6

Link that resides between computer networks and is responsible for converting data passing through into the appropriate format so it can be understood by the recieving network.

Front 7

Handshaking

Back 7

Exchange of predetermined signals to signify that a connection has been established between 2 systems

Front 8

Hub

Back 8

Network connection point for devices (using an ethernet cables attached to a port; there can be multiple). Data arriving at a hub is copied and sent to all the devices on the network. The device waiting to receive it accepts it while the rest ignore it. This is inefficient, slow and causes lots of traffic over the network.

Front 9

ISDN

Back 9

International communications standard that allows for the transmission of audio/video and other data over digital telephone lines.

Hint 9

Integrated Services Digital Network

Front 10

LAN

Back 10

Computer network where all the connected computer are within a limited geographical area (E.g. a home or school).

Connections between computers may be through cables and/or microwave transmissions.

Hint 10

Local Area Network

Front 11

Modulator/demodulator/modem

Back 11

Electronic equipment that converts computer digital signals into audio signals and back.

Hint 11

The audio signals are transmitted over telephone lines, which allows for distant communication.

Front 12

Network

Back 12

Computer systems that are interconnected and can share resources and data.

Front 13

Packet

Back 13

Group of bits. May include control signals, error control bits, coded information, as well as destination for the data.

Front 14

Packet switching

Back 14

Network communication method that creates and transmits small units of data, called packets, through a network, independently of the overall message.

Front 15

Networking

Back 15

Making use of a network

Front 16

Parity bit

Back 16

Error-detecting procedur that appends a binary digit to a group of binary digits. The sum of all the digits, including the appended binary digit, establishes the accuracy of the data after input, transmission, storage or precessing.

Front 17

Protocol

Back 17

International rules that ensure the transfer of data between systems.

Hint 17

A protocol that is recognised as the standard for a specific type of transfer is call standard protocol. (E.g. TCP/IP)

Front 18

TCP/IP

Back 18

Communications protocol used to connect hosts on the internet.

Hint 18

Transmission Control Protocol/ Internet Protocol

Front 19

WAN

Back 19

computer network where all the connected computers are in a larger geographic area than that served by a LAN or a MAN (metropolitan area network)

Hint 19

Wide Area Network

Front 20

Server

Back 20

Can be either a computer system or software application that provides a service to the other computer systems connected to the same network. E.g. a server can provide the ability to the rest of the computers on the network to store and share files, taking the role of a file server.

Front 21

Client

Back 21

Can either be a computer system or a software application that requests a service from a server connected to the same network. E.g. an email client software application can request from an email server software application to fetch any new emails that may have been received.

Hint 21

Requests content from server while not sharing any of its resources.

Front 22

Way in which one can connect 2 or more computer systems to make a network.

Back 22

• Hub

• Switch

• Router

Front 23

Switch

Back 23

Similar to a hub however, it can identify which network device is connected to which port. When a network device wishes to send data to some other device on the network, it sends the data to the switch which then sends the data to the appropriate receiver.

Hint 23

Much faster than a hub

Front 24

Router

Back 24

It's use is to join multiple networks and to serve as an intermediary between them so that data can be exchanged effectively. E.g. can be used to connect a home network to the internet.

A hub/switch and a router are usually integrated into a single box, allowing the creation of a wired and wireless network, as well as connection of that network to other networks such as the internet.

Hint 24

It is a more sophisticated device than both a hub and switch.

Front 25

Types of networks

Back 25

• Local Area Network (LAN) • Wireless Local Area Network (WLAN) • Virtual Local Area Network (VLAN) • Wide Area Network (WAN) • Storage Area Network (SAN)

• Extranet

• Virtual Private Network (VPN) • Personal Area Network (PAN) • Peer-To-Peer (P2P)

Front 26

Benefits of LAN

Back 26

• Allows sharing of peripheral devices between the connected computer network. This eliminates the need to buy certain peripheral devices for every computer (E.g. printers).

• Data can be shared. Allows clients to exchange data without using physics means such as USB sticks. This increases flexibility and reduces wasted time.

(Most common technology used to build wired LAN is a hub or switch using ethernet cabling.

Hint 26

Front 27

WLAN

Back 27

Similar to LAN but uses wireless connection methods instead. This allows the user to have mobile devices and laptops connected to the network and be able to move around.

WLANs have all the benefits of LANs but they can be less secure that wired LANs because they can be assessed by anyone who can find access to the wireless signal.

Most common technology used to make WLANs is WiFi which allows the exchange of data between computer systems using radio waves.

Hint 27

Front 28

Similarities and differences between LAN and WLAN

Back 28

Similarities: both act on a local level - both allow communication - both are used to connect devices - both allow sharing of resources.

Differences: they use different transmission mediums - LAN is safer - LAN is faster - WLAN offers greater flexibility.

Front 29

VLAN

Back 29

A network of computers that behave as if they're connected to the same topoly but are physically located in different segments of a LAN.

VLAN configurations are generally compromised and maintened via software rather than hardware. This makes the network really flexible as it allows computers to be removed from the VLAN and located elsewhere without having to physically rewire the whole system to fit the new configuration.

Hint 29

Virtual Local Area Network

Front 30

Similarities and differences between LAN and VLAN

Back 30

Similarities: both act on a local level - both have the same attributes - both allow communication - both allow sharing of resources

Differences: the formation of virtual work groups is easier - VLANs offer great flexibility. Even if someone who is using a laptop moves they will remain to their dedicated VLAN. - VLANs Are independent on the medium and the physical topology of the network. - the management/administration of a VLAN is more complex.

Hint 30

Front 31

WAN

Back 31

Connects computer systems that are within large geographical areas. The internet is an example of a WAN. It typically consists of LANs connected over a broad geographical area. Often one node on a LAN is set up at a gateway to handle all communication going through that LAN and other networks.

Hint 31

Wide Area Network

Front 32

SAN

Back 32

It's a network that was created so that large storage devices can be accessible from servers in a convenient way. It is needed because there needs to be enough storage for certain tasks to be completed.

Hint 32

Storage Area Network

Front 33

Intranet

Back 33

Botas term for a collection of private computer networks within a company, school or organisation for example which utilizes protocols like TCP/IP.