Networks - 1.3.1 Flashcards
What is a LAN (4)?
Local area network
Covers a small geographical location
Either wired or wireless
Owned by the organisation that uses it e.g. businesses, schools, universities
What is a WAN (3)?
Wide area network
Connects LAN’s in different geographical areas
Organisations hire infrastructure as it’s much more expensive
The internet
What is a network(2)?
Two or more computers connected for the purpose of communication
Connected by a wired medium
Advantages (3) & disadvantages (4) of using a network:
File sharing
Communication
Roaming access
Cost - additional equipment is required
Management - technical staff needed
Spread of malware
Hacking
What is a NIC (3)?
Network interface controller
Allows devices to connect to a network, both wired and wireless connections
Built into the motherboard
What is a switch (2)?
Connects devices in a LAN
Receive data from one device and transmits it to the device on the same network with the correct MAC address
What is a router (3)?
Transmits data between networks
Always connected to at least 2 different networks
Directs data in packets to their destination
Used in homes and offices to connect the LAN to the internet
What are the different Ethernet cables to connect devices on a LAN (3)?
Twisted pair cables - most common, least expensive transmission media,
Coaxial cables - surrounded by insulation and a shield of braided wire to avoid interference
Fibre optic - transmit data as light, high performance, DONT suffer interference, large distances
How does a wireless network work? Examples:
Uses radio waves to transmit data
Bluetooth - direct connection between two devices
Wi-fi - multiple devices connect to a LAN at the same time
Features of Ethernet (5):
Stable connection
Faster traffic speed
Good quality signal
Reduced possibility of being hacked
Slower transfer speeds
Features of Wireless (6):
Can connect to multiple devices without needing extra hardware
Vulnerable to hacking and interference
Signal quality reduces through walls
Less disruption to building - less wires
Cheap set up costs
Not as stable connection
What are the factors affecting network performance (3)?
Bandwidth - greater bandwidth means better performance
Number of devices in network
Network latency - period of time delay in computer system
What is a client - server network?
Server provides services to other computers on the network or manages and stores files e.g file server, web server, print server
Clients are computers that rely on other computers (servers) to manage and store data
Best for organisations with many computers or computers that need to access the same data e.g. schools
Pros (5) & cons (4) of client-server:
Easy to keep track of files
Easy to do backups
Easy to install and update software
Easier to manage network security
Servers are reliable and always on
Expensive
Need IT specialist to maintain
Server dependence
Server may become overloaded
What is a peer-peer network (3)?
All computers are equal
Files are stored and managed in individual devices
Best for smaller organisations with less computers
Pros (2) & cons (3) of a peer-peer network:
Easy to maintain - don’t need expertise or expensive hardware
No dependence in the server
No centralised management
Copying files between devices creates duplicate files
Less reliable as data is lost if one fails
What is a topology?
Layout of a network
What is a star topology?
All devices are connected to a central switch or server that controls the network
May be wired or wireless
Pros (3) & cons (2) of star topology:
If a device fails then the rest of the network is unaffected
Simple to add more devices
Few data collision
Every device needs a cable - can be expensive
Problem with the switch/server affects the whole network
What is a mesh topology?
No central server or switch
Every device is either directly or indirectly connected to each other
Work by sending data across the fastest route
Pros (2) & cons (1) of mesh topology:
No single point where the network can fail
If one device fails the data is sent along another route
Very expensive - many wires needed
Difference between partial and full mesh topology:
Full mesh - every device is connected to every other
Partial mesh - not all devices are fully conmected
What is the internet?
A network of networks p - a WAN which connects devices and networks all over the world
Lots of fibre optic cables running across the sea
What is a DNS (2)?
Domain Name Service
Used to translate domain names into IP addresses
