1.3 Computer networks, connections and protocols Flashcards
What is a LAN
Network that covers a small geographic area and all hardware in it is owned by the users of it
Where would you usually see a LAN
Business, school
Advantages of a LAN
Sharing files is easier
Share hardware
Easier communication
Network-wide updates
Network-wide internet connection
Monitoring
What is a WAN
A network that is spread over a large geographical area, connects LANs together
Hardware used is not owned by organisation using it
Examples of WANs
Internet, Buisness spread over large area
What is a NIC and what does it do
Network Interface controller
Internal piece of hardware that connects to a network
What does a switch do
The switch is sent data and specifically and intelligently chooses which computer to send the data to
What does a hub do
Forwards data packets along a network
What does a router do
Transmits data between networks
Pros of wired network
Cost-effectiveness
Reliability
Security
Cons of wired network
Maintenance
Cannot physical run cables through places
Cost
Pros of wireless network
Mobility
Lower cost
Easier to maintain
Cons of wireless network
Security
Lower speed
Connectivity
Example of wired network
Ethernet
Examples of a wireless network
Bluetooth
Wi-Fi
Factors that effect performance of a network
Error rate
Devices on network
Latency
Bandwidth
What is bandwidth
The amount of data that can be transferred in a given time
How does a client server model work and how do the clients get data
A server in the middle connected to a lot of clients on the outside
Clients request to have access to the files contained within the server and this sever sends files to whoever requested them
Pros of client server model
Reliable as its always on
Security
Easier to install software
Cons of client server model
Expensive
Dependent on server
Needs good transmition media
What is used to transfer data wirelessly
Radio waves
What is transmition media
What is used to transmit the data
Types of wired transmition media
Twisted copper pair
Coaxial cable
Optic FIbre cable
How does a Peer to peer network work
All computers are connected to each other and act as clients and servers
Pros of peer to peer networks
Easy to maintain
Not dependent on server
Cons of peer to peer networks
No centralised management
Less reliable
Hard to copy files to all devices
What is a star network topology
Where all of the computers are connected to a central switch and not to each other
Pros of star network topology
If a device fails it still works
Better performance
Less wires needed
Cons of star network topology
If the switch breaks whole network breaks
Every computer needs to be connected to switch
All 4 topologies
Star
Mesh
Ring
Bush
Mesh network topology
Where all devices are connected to each other instead of a switch
Pros of mesh network topology
Better coverage
Not reliant on switch
Cons of mesh network topology
Lots of wire needed
Harder to expand network
What is a network protocol
A set of rules for transmitting processing and processing data
What type of address does communication in the same network use
MAC address
What are MAC addresses formatted/ shown as
48/64 bit numbers
How are MAC addresses used
Switches used MAC to send data to the right reciever
What addresses does communication between networks
IP
What are the 2 versions of IP
IPv4 IPv6
How are IPv4 addresses shown
8-bit chunks
or denary numbers seperated by full stop
How are IPv6 addresses shown
16 bit chunks
or Hexadecimal sperated with colon
What is TCP/IP
A protocol that dictates how data is sent between networks
TCP means and does
Transmition Control Protocol
Protocol for how devices connect on a network
IP means and does
Internet protocol
Directs packets to designated locations
HTTP means and does
Hypertext transfer protocol
Used by web browsers to access web servers
HTTPS means and does
Hypertext transfer protocol secure
Used by web browsers to access web servers securely
FTP means and does
File transfer protocol
Used to transfer files between devices on a network
POP means and does
Post office protocol
Used to retrieve emails from a server then it is deleted from server
IMAP
ussy
Internet Message Access protocol
Used to retrieve emails from a server it is copied from server
SMTP means and does
Simple mail transfer protocol
Used to send emails
What is a layer of a network protocol
A group of protocols that have similar functions
Say the 4 layers of the TCP/IP network protocol
1 Network access layer
2 Internet layer
3 Transport layer
4 Application layer
What are the advantages of using layers of network protocols
Breaks network protocol into manageable sections
All layers can be changed without affecting other layers
Having standards for each layer makes companies use universal software
What are standards
Agreed ways of doing things for example transmitting data
What is the internet
A WAN
Networks of networks
What is the World Wide Web
A collection of websites hosted on the web servers of the internet
What are Domain Name Services used for
Convert URLs into domain names then into IP addresses by checking them on the domain name server
What are URLs
Addresses used to access web servers
What do Domain Name Servers do
Hold a large store of domain names
Why are standards needed
For different hardware across networks to interact
What is hosting
When a company uses its servers to store the files of another company
What is ‘the cloud’
Storage devices, processing power and applications the exits remotely over the internet
What is a WAP
Wireless Access Point
A switch that allows devices to connect wirelessly
Pros of the cloud
Users can access files and apps from any device
Easy to increase available storage
Don’t have to buy expensive hardware
Back ups
Automatic updates
Cons of the cloud
Need to be connected to internet
Dependent on host
Can be hacked
Subscription fees
What is encryption
When data is scrambled while being sent to another computer
Sending data over network securely
