Networks Flashcards
Network
A group of devices connected together so they can communicate with each other and share resources.
Why are computers connected in networks?
- Share data and info
- Communicate using email, messaging, video conferencing
- Collaborative work
- Share hardware
- Centralised support and maintenance
- Socialisation
LAN
Local Area Network
Infrastructure owned and maintained by the organisation.
WAN
Wide Area Network
Telecommunications links managed by other companies.
Organisations that run their own WANs will often lease bandwidth from telecommunications companies.
Others cannot use its’ infrastructure, making it secure. However, the infrastructure can be expensive to install and maintain.
Wired
Harder installation
-> (each device has a dedicated cable)
Difficult to diagnose problems
-> (all cabling needs inspection)
Cannot move around
-> (limited to area covered by cable)
Longer range
-> (copper is better at signal transmission than air)
Larger bandwidth
-> (copper is better at signal transmission than air)
Better latency
-> (less susceptible to interference from outside sources as the cables have coverings to protect them)
Wireless
Wireless may save cabling costs
-> Not every device needs a dedicated cable
WAPs still need to be installed
-> Diagnosing problems is easier
Lower range
-> Quality lost through floors and barriers between device and WAP
Lower bandwidth
-> Transmission through air doesn’t support high speeds
Lower latency
-> Radio waves disperse over large distances, slowing data transfer
Protocols
Sets of rules that govern the communications within devices.
For two devices to communicate, they must use the same protocol.
Network protocols
Ethernet
Wifi
TCP/IP
HTTP
HTTPS
FTP
Email protocols
POP3
SMAP
IMAP
4 layer protocols (ATIL)
Application
Transport
Internet
Link
Internet
Largest hardware network of networks
POP3
- Post Office Protocol.
- Used by email clients to retrieve email.
SMAP
- Simple Mail Access Protocol
- Accessing email stored on a server.
IMAP
- Internet Message Access Protocol
- Enables access to emails using multiple email clients
TCP/IP
- Transmission Control Protocol / Internet Protocol
- Protocol stack used when connecting a device to the internet.
HTTP
- Hypertext Transfer Protocol
- Governs communication between webserver and client