Topic 5 - Computer Networks Flashcards
What is a computer network?
Multiple devices connected together that can share resources
What are the advantages of a network?
Share resources, data and peripherals
Centralised back-ups
Centralised updates
Centralised security
Connect globally
User monitoring
What are the disadvantages of a network?
Expensive to set up
Requires specialists skills
Viruses spread through connections
Less secure
Explain the peer-to-peer model
Each device acts as a client and a server
What are the advantages of the peer-to-peer model?
Not dependant on single server
Cheap to set up
Resources easily shared
Fast -can request from closest device
What are the disadvantages of the peer-to-peer model?
Sharing peripherals slows down if too many requests
No centralised back-ups
No security
Explain the client server model
Client makes requests, server fulfils those requests
What are the advantages of the client server model?
Files stored on central serve
Client breaking won’t affect network
Centralised back-ups
More secure
What are the disadvantages of the client server model?
Expensive to set up
Requires specialist skills
If serve fails, network fails
Suspectable to hacking
What does PAN stand for?
Personal Area Network
What does LAN stand for?
Local Area Network
What does WAN stand for?
Wide Area Network
What is PAN used for?
A single user with multiple device
ie. smart watch and phone
What is LAN used for?
Multiple users in a single building
ie. small office
What is WAN used for?
Multiple devices connected across a large geographical area (sometimes multiple LAN’s)
ie. Large companies in multiple countries
What is a Wireless Access Point?
A device used to connect devices to a wired network ie internet
What does a router do?
It moves data from one network to another
Connects networks to the internet
What does a switch do?
It is responsible for connecting data to the right device in wired connections
What does a hub do?
Broadcasts data to all connected devices
What does a Network Interface Card do?
Enables a wired connection between a computer and networked devices
What does a Network Interface Card contain?
MAC address
What does a bridge do?
Connects two LAN’s together to reduce traffic
What is a MAC address?
A unique physical address used to locate devices on a network
How does a star topology work?
The central node represents a hub or switch
How does a bus topology work?
All nodes are connected on a single cable, data is sent to all nodes in both directions.
The terminators stop signals from being deflected back down the cable
How does a ring topology work?
Data is transferred in one direction to all nodes
How does a mesh topology work?
The most efficient route to transfer data is calculated
What are the advantages of the star topology?
Damaged link only affects one node
Easily add new nodes
Works well under heavy load
What are the disadvantages of the star topology?
Central node failing affects all nodes
Expensive due to cabling
What are the advantages of the bus topology?
Cheap - 1 cable
Simple to set up
Works well for small networks