1.3.3 Networks Flashcards Preview

A Level Computer Science > 1.3.3 Networks > Flashcards

Flashcards in 1.3.3 Networks Deck (74)
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1

Define a network

Two or more computers connected together, to share information and resources

2

Define a LAN

Local Area Network:

A connection of devices

In a small geographical location

3

What are the advantages of a LAN?

  • Enables privacy from the outside world
  • Can control the access to data/programs
  • Can control the access to devices

4

What are the disadvantages of a LAN?

  • Requires some expertise to install and maintain
  • Can be costly for a larger LAN
  • Unauthorised access to data depends on personnel and their security measures

5

Describe the role of an NIC

Network Interface Card:

Converts data signals from a node into one that can be transferred over a network

6

Describe the role of a switch

Connects all the nodes together; intelligent so can send data packets only to their intended destination

7

Describe the role of a hub

Connects all the nodes together; not intelligent so data packets are transmitted across the whole network

8

Describe the role of a router

Manage data packets, enabling them to be sent between networks

9

Describe the role of a WAP

Wireless Access Point:

Allows nodes to connect to the network wirelessly

10

What is the difference of a client-server network over a peer-to-peer network?

  • A computer is designated as the server, rather than all having the same status
  • Server manages network traffic and data requirements, thus having less collisions and being faster
  • Larger networks have more servers, this can handle a greater network demand
  • Popular of companies, rather than home networks

11

Advantages and disadvantages of a bus network topology

  • Cheap, due to all nodes being connected to one cable

 

  • Data collisions slow the network - travels both ways
  • Whole network suffers from cable faults
  • Only useful over small areas

12

Advantages and disadvantages of a ring network topology

  • Cheap: only one cable
  • One-way data travel - no collisions

 

  • Whole network suffers from cable faults

13

Advantages and disadvantages of a star network topology

  • Other nodes are unaffected from a cable fault

 

  • Can be costly with large number of nodes
  • Network will slow with multiple nodes requesting data or software at the same time

14

Advantages and disadvantages of a mesh network topology

  • Every node is connected
  • Other routes are available to combat high network traffic or cable faults

 

  • Very expensive: large amounts of cabling required

15

What is the difference between a LAN and a WAN?

LAN: Located on one site, owner owns the network devices

WAN: Covers a large geographical area, devices can be provided by telecoms companies

16

Explain 'Web Hosting'

A computer on a network: serves users of the internet as a host.

Websites are usually hosted on servers for people to access them (sometimes for a fee)

17

Explain 'IP address'

Internet Protocol Address:

A unique number given to every computer on the internet.

Identifies the computer, may change each time a network is joined

18

Explain 'ISP'

Internet Service Provider:

The company who provides you with an internet connection

19

Explain 'URL'

Uniform Resource Locator:

The name for a web adress

20

Explain 'DNS'

Domain Name System:

The system used to find the computer hosting the required website

21

Explain 'the Cloud'

A network of servers hosted on the internet, offering a range of services for data

22

How does a DNS work?

  • The website's URL is entered
  • The URL is sent to the ISP, where it is looked up in their DNS's address book
  • The required IP address is returned to you, to communicate to the computer hosting the website

23

Advantages of the Cloud

  • Don't need to buy and install software
  • Any connected device can access the service
  • No need to upgrade software
  • Collaborative documents can be formed
  • Work is saved automatically

24

Disadvantages of the Cloud

  • Sensitive data stored in other countries may be under different data laws
  • Can be less secure than local storage
  • Completely reliant upon the network/internet

25

What is the role of an internet registrar?

  • Holds the details of domains available for purchase
  • Registers company details
  • Resolves domain name disputes

26

How are files sent over the internet?

They are split into data packets before being transmitted

27

What are the components of a data packet?

Data

Error check

Packet header

28

Describe the Error check within a data packet

Includes a checksum number: a calculation for checking if all the data has arrived uncorrupted

29

Describe the Packet header within a data packet

Sequence number: for data packets to be put back together in the right order

Return address: when needed to notify the sender's computer if the packet has been received or has been corrupted

Destination address: so the packet arrives in the correct location

30

Define a protocol

A set of rules for devices to follow