AQA 7517 4.9.4.2: Standard application layer protocols
The free BugBot lesson that teach this point, a robot to try it on, and the past-paper questions that test it.
What it covers
At GCSE (F10.7 and F10.8) you named the four layers of TCP/IP and matched protocols to what they do. At A level you need to explain what each layer adds as data goes down the stack, how ports and sockets let one computer run many conversations at once, and how the standard application protocols are used, down to the commands a client sends.
- Four layers
- Ports and sockets
- The application protocols
- A packet of your own
Or do it in the simulator, with tasks that mark themselves
Lessons that teach it
- A12.4 The TCP/IP stack and protocols Networks and the web
The four layers, encapsulation, ports and sockets, and HTTP, HTTPS, FTP, SMTP, POP3 and SSH.
Try it on a robot
The task from A12.4 The TCP/IP stack and protocols, running here. Change the program and press Run.
The specification is AQA's own document; this page says which of our lessons teach point 4.9.4.2 and is not endorsed by the board.