AQA Computer Science GCSE
Networks - Network Protocols
Network protocols are sets of rules that are used to allow devices to communicate with each other effectively. Without protocols it would be impossible for one device to undersand the data sent from another.
Protocols are particularly important when it comes to sending data over the internet.
Protocol Intro - slides I use in class
The 8+2 Protocols - ten in total
Protocols - textbook style resource which deals with the protocols you need to know
Protocols Summary - for revision
This is the full detail, adapted from a markscheme, of what you might need to know about each protocol.
You also need to make sure that you know about the Ethernet and Wi-Fi families of protocols. They don't really fit in the table, so make your own notes on these.
Packet Switching - slides to explain how TCP and IP work (but not the TCP/IP layers)
This is a part of the exam where you might see multiple choice questions.
You'd never see eight mutiple choice questions in a row like this, but you might easily see 2 or 3. The exam board rules for answering these questions are show below:

It would be best if you didn't need to make corrections as it seems quite complex! My tip of multiple choice questions is not to go anywhere near the answer lozenge to beging with. Mark down the left side which answers you know aren't the right answer first, leaving the possibilities. Then go on to the next question and come back to the multiple choice questions later.
At that point you can check again and make sure you have narrowed the possible answers down as much as you can. Then you go for your answer. The important thing is that you come back to them - they're really easy to mis-read the first time and you really don't want to end up having to go through the changing your answer procedure - especially not if you then decide that you were right the first time!
There are 8 protocols and two protocol families you need to know. You just need to learn them for the exam really - you don't need to know all that much about them, just what they do and which layer of the TCP/IP model they are in.
The TCP/IP Model
The TCP/IP model describes how the protocols and families of protocols work together to allow devices to access a network.
This uses the client-server model.
The Client-Server model - slides to describe the basics of the model
You need to know the layers in the TCP/IP stack, what they do and the order they go in as well as which layer each protocol fits in to. If you can see how the model works then that's great, but most questions you get on this will be related to the stack itself.
The basic TCP/IP model - the stack and what's in it
The TCP/IP model - text book notes and activities
Explaining the TCP/IP model - how it works
Here's a one slide summary which might help with revision.
TCP/IP summary - everything you have to know on one slide