Networks - Protocols (TC/IP Model) Flashcards
What is a protocol?
A set of rules for how devices communicate and how data is transmitted across a network
What do protocols do?
Cover how communication between two devices should start and end
How data should be organised
What the devices should do if data goes missing
How is data sent between networks?
Split into equal-sized packets
Each packet contains extra information such as the destination and source address and a checksum
What is a checksum?
It is used to find errors
How are network protocols divided?
They are divided into layers
What is the rule about the travel of data between layers?
Data can only be passed between adjacent layers
What is a layer?
A group of protocols which have similar functions
What are layers?
Self-contained - protocols in each layer do their job without needing to know what is happening in other layers
What do each layer do?
Each layer serves the layer above it (does the hidden work needed for the action above) - layer 4 triggers actions in layer 3 which triggers layer 2…
What are the 4 layers of the TCP/IP model?
Layer 4 - application layer
Layer 3 - transport layer
Layer 2 - internet layer
Layer 1 - link layer
What does layer 4 do?
The application layer provides networking services to applications - turning data into websites
What does layer 3 do?
The transport layer sets up communications between 2 devices - splits data into packets and checks packet are correctly sent and delivered
What does layer 2 do?
The internet layer adds IP addresses to data packets, directing them between devices and handling traffic - used by routers
What does layer 1 do?
Passes data over to the physical network and is responsible for how data is sent as electric signals over cables, wireless and other hardware and is responsible for interpreting signals using device drivers
What do device drivers do?
Act as a translator for signals between the OS and type device you are using
What are the advantages of using layers?
- Break down the communication into manageable chunks
- Layers can be changed without other layers being affected
- Having set rules for each layer forces companies to make compatible and universal software and hardware
How does breaking down networks into manageable chunks help?
It helps developers concentrate on only 1 area of the network without having to worry about the others
Why is having a set rules for each layer good?
It forces companies to make compatible and universal software and hardware so different bread can work with each other and will work in the same way
What is the application layer responsible for?
Files, email and data transfer
What are protocol examples of the application layer (layer 4)?
HTTP, HTTPS, FTP, SMTP and IMAP
What are protocol examples of the transport layer (layer 3)?
TCP and UDP
What is a protocol example of the internet layer (layer 2)?
IP
What are the protocol examples of the link layer (layer 1)?
Wi-Fi and Ethernet