Brainlag PlusWhat each common protocol does, the four-layer TCP/IP model, how packet switching moves data across the internet, PANs, and how a network is kept secure.
Protocols
A protocol is a set of rules for sending and receiving data.
Standards let equipment from different makers work together.
| Protocol | Job | Layer |
|---|---|---|
| HTTP / HTTPS | web pages (HTTPS encrypted) | Application |
| FTP | transferring files | Application |
| SMTP | sending email to and between mail servers | Application |
| IMAP / POP | reading email (IMAP keeps it on the server; POP downloads it) | Application |
| TCP / UDP | splitting into packets, ordering and checking (UDP: faster, no resending) | Transport |
| IP | addressing and routing packets | Internet |
| Ethernet / Wi-Fi | sending frames on the local network | Link |
Layers split the job up: each layer has its own protocols and only talks to the layers next to it, so one layer can change without the others.
The rest of this lesson and its 13 practice questions are in Plus.
Screen 1 of 4, free to read.
- 13 exam-style questions, marked as you go, each with a worked solution
- Anything you get wrong is saved to your flashcards