Summary GCSE AQA Computer Science - TCPIP model

TCP/IP model

- TCP/IP
- Broken down, send through internet, packet switching to put it back together
- Error control bits
- Check for errors in packet to make sure they not been corrupted in transport
- Data
- Part of file you want to send
- Source IP address
- Where the packet comes from
- Destination IP address
- Where to send the packet
- Packet identification
- Allows the computer to know how and in what order to reassemble the
packets
- Model Layers
- Application layer
- Interacts with the user from appropriate application software
- HTTP, HTTPS for web browsers
- FTP for file transfer
- SMTP, IMAP for email
- Transport layer
- Splits data into the packets
- Packet switching
- UDP, TCP
- Internet (Network) Layer
- Adds the source and destination IP address and route packets over
the network
- IP
- Link (data) Layer
- Adds the MAC address of the hardware of both sender and receiver
- Each MAC address is the physical address of the specific device

Layer Order Sender Order Recipient Order
1 Application Link
2 Transport Internet
3 Internet Transport
4 Link Application
- Both models go through internet to send data