Networks Flashcards
What is LAN and what are some characteristics of it?
Local Area Network (e.g. school or office)
Computers connected over a small geographical area
Hardware is internally owned
What is WAN and what are some characteristics of it?
Wide Area Network (e.g. across country or the world)
Computers connected over a large geographical area
Hardware owned by 3rd parties
What are some factors that can affect the performance of a network?
The bandwidth available
Number of users connected
Number of data collisions
Interference (e.g. walls)
Applications being used
What is bandwidth?
The amount of data that can be transferred in a given time
Why does number of user affect the performance of a network?
Too many users may cause congestion and slow the network
What is a client-server network?
Clients make requests to the server in which the server responds to these request
Advantages of a client-server network:
Network controlled centrally - easy to backup and update software
Hardware, software and data can be shared across the network (e.g. printer)
Clients can easily be added to the server
Disadvantages of client-server network:
Traffic congestion causes network to slow down
If fault occurs the whole network will close
Malware can easily spread across the network
What is a peer-to-peer network?
Data is directly shared between systems without requiring a central server
Advantages of peer-to-peer network:
Simpler to set up than client-server network
Clients aren’t dependant on server
Perfect for quickly sharing files between systems
Disadvantages of peer-to-peer network:
No central device to manage back-ups or security
Performance decrease when more devices connect to network
What is the hardware is needed for a computer to connect to LAN?
Wireless Access Point
Routers
Switches
Network Interface Card
Transmission media
What tasks are performed by a Wireless Access Point?
Allows other devices to connect to a network using standards such as Wi-Fi and Bluetooth.
What tasks are performed by a Router?
It receives data packets and uses the IP address in the packet header to determine the best route to transfer data
What tasks are performed by a Switch?
Receives a data packet from a node and reads the destination address in the packet header and forwards packet directly to destination
What tasks are performed by a Network Interface Card?
This is required for a computer to connect to the internet
Examples of transmission media:
Ethernet, Fibre Optic Cables, Coaxial cables
What is a data packet?
Files broken down into smaller parts which makes it faster to transfer across network
What is the ethernet used for?
In a LAN used for transferring data between nodes and hardware
What is fibre optic cables used for?
To send data quickly across a WAN
What is coaxial cables used for?
Not used much now as they can be affected by electromagnetic interference
What is a network?
A computer network is two or more computers connected together
What is the purpose of networks?
To share resources like hardware, software and data
What is the concept of the internet?
It’s a global network of interconnected networks
What is a Domain Name Service made up of?
A DNS is made up of multiple Domain Name Servers
What are the steps on DNS to display a web page
- Domain name is typed into address bar of browser
- Query is sent to local DNS server for corresponding IP address of the domain name
- Checks if it holds the IP corresponding to the domain name and passes IP address to browser
- Browser connects to the IP address of the server and accesses the website
What is hosting?
Storing files and data on a web server
What is the cloud?
Remotely accessed storage which is accessed through the internet
Advantages of the cloud:
Data can be accessed from any device using that internet
Data is backed up by a third party
Frees up space on own computer
How does a star topology work?
Each computer system is connected to a hub/ switch
Disadvantages of the cloud:
Won’t be able to tell if someone else is accessing your data
No guarantee that data is backed up
No internet means no access to your data
Advantages of star topology:
Cheaper than cabled mesh
Easy to add extra nodes
Fewer data collisions
Disadvantages of star topology:
Requires a network switch
Requires a network manager
If central device fails the whole device fails
How does a mesh topology work?
Data packets are transferred to the device using the quickest path
Advantages of mesh topology:
Data can take alternate routes if one cable fails
Can withstand large amounts of traffic
New systems can be added without disrupting the entire topology
Disadvantages of mesh topology:
Impractical for full mesh networks - a lot of connections
Many connections means it requires a lot of maintenance
