Networking: Overview / Recap & Revise, Part 1
Explanation: This is the first of two pages that helps you recap and revise the Computer Science “Networking” module. It could also function as a launch page to give you an overview and to “signpost” you to the right pages in the right order if this is the first time you’ve come to this topic (e.g. you’ve just joined the school).
This whole module is about networking – that is, connecting computers together so that they can do more. It does not automatically mean “the Internet”, but that can be part of it. You could have network in an office or home that goes nowhere near the Internet, and is just used to share printers and scanners, to share file servers, and to allow users to share work and collaborate (e.g. via email). We will look at what a network is, the different types, the hardware you need to make one and the different types of connection you can have between computers. In Part 2, we will look at services available on the Internet and the World Wide Web, different network architectures, and virtual networks.
Different Types of Network
Why do we network computers together at all? There are pros (advantages) and cons (disadvantages) to doing so, as explained in the main lesson, Year 9 – Computing – Networking – LAN/WAN.
Networks can be divided up into different types according to how they’re used and how large they are – the two main types are Local Area Networks (LANs) and Wide Area Networks (WANs), as explained in the main lesson, Year 9 – Computing – Networking – LAN/WAN.
You can also have a WLAN, which is just a LAN that is connected wirelessly.
There are other types – e.g. Wireless Personal Area Networks (WPANs), which means your personal “bubble” of connections over a much shorter range than a LAN (e.g. your phone connecting to your headphones, smart watch and heart-rate monitor over Bluetooth).
There are other, less commonly used, sizes of network too, including Body Area Networks (BANs) (which can be used, for example, in assisted living and healthcare applications, e.g. see University of Bristol project SPHERE*), Metropolitan Area Networks (MANs), and so on.
* I was involved in the home-trials phase of the SPHERE project, and was a volunteer in the spin-off “Dress/Sense” project… if you squint really carefully in the celebration video, I think you catch a glimpse of me in the background at one point!
1) Give two advantages, and two disadvantages, of networking computers together.
2) What’s the difference between a LAN and a WAN? What do LAN and WAN stand for?
3) Stretch: List some different types of *AN (e.g. PAN) – what are they, what do they stand for, and how do you tell them apart from LAN, WAN and all the others?
Performance of Networks
Network performance is how quickly, and how well, you can transfer data across your network (e.g. think of streaming a movie on Netflix – if your network performance is not up to it, it will buffer, drop frames, freeze, show digital artefacts, etc. etc.). Video streaming is one example of something that is sensitive to network performance – online gaming is another classic example that demands a lot of a network (whereas if you’re, say, copying a load of files across the network, so long as they get there uncorrupted in the end, the only problem with poor network performance is that it’ll take longer to do it). Have a look at the content, videos and tasks in the main lesson, Year 9 – Computing – Networking – Performance, then try the Tasks below.
1) What is network performance?
2) List at least three factors that can affect the performance of a network.
3) Stretch: My household has four people in it. During the 2020 COVID-19 lock-down, there are two parents trying to work from home, including frequent video-conferencing, one adult daughter (university student) watching online lectures and having video-conferences with her tutors, and one Year 11 daughter who has suddenly found she has lots of time on her hands so is hammering Netflix, Amazon Prime and Disney+. What problems can you foresee happening, and how could they possibly be fixed?
To convert your collection of computers into a network of computers there needs to be some additional hardware. The computers themselves may need to have hardware added to enable them to network, and there is some supporting hardware needed to get it working – even more if you want to connect to the Internet and/or want to have wireless connectivity too. Have a look at the content, videos and tasks in the main lesson, Year 9 – Computing – Networking – Hardware, then try the Tasks below.
1) What does “NIC” stand for, and what does it do?
2) What’s the difference between a switch, a router and a modem?
3) Stretch: Draw an imaginary network layout (or do your home or school) – label the key pieces of hardware.
Connecting Your Network Together
In addition to using the taxonomy of network size and usage (PAN < LAN < WAN etc.), we can also divide networks up into “wired” and “wireless” according to how we’ve connected them together. The main lesson, Year 9 – Computing – Networking – Transmission Media, goes into several examples of different wired (e.g. Ethernet, optical fibre) and wireless (e.g. Wi-Fi, cellular) transmission media – once you’ve had a look at that, try the Tasks below.
1) What’s the difference between wired and wireless connections? Give an example of each.
2) What are the pros (advantages) and cons (disadvantages) of wireless vs. wired?
3) Stretch: A friend of yours wants to play online games and stream videos from the Internet at the desk in their room – would you recommend that she sets up a wired or wireless network?
4) Stretch: Another friend of yours wants to keep up to date on SnapChat, TikTok and occasionally Facebook if her parents insist when she’s sat in the living room or in her room, and occasionally looks at recipes online when cooking. Would you recommend that she sets up a wired or wireless network?
To wrap up your learning on this, try this Quizizz quiz, “Year 9 – Computing – Networking – Overview, Part 1“.