That Blue Square Thing

AQA Computer Science GCSE

February 2019: this area of the site is being built just now. There are areas where there is no content yet. That will get added over the next 6 months or so.

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.

PDF iconProtocol Intro - slides I use in class

PDF iconProtocols - deals with all the protocols you need to know

PDF iconProtocol Table - to complete

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.

PDF iconPacket 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.

PDF iconMultiple 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:

multiple choice question rubric diagram

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.

PDF iconThe 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.

PDF iconThe basic TCP/IP model - the stack and what's in it

PDF iconTCP/IP table - to complete

PDF iconTCP/IP summary - everything you have to know on one slide

PDF iconExplaining the TCP/IP model - how it works