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Computer networks

Free Network basics lessons

5 lessons, about 1 hour in all. Each teaches one idea with a visual, then gives you a problem or a few questions on it. Read the lessons here, then create a free account to practise and keep your progress.

Start free with lesson 1See the full Network basics path

Stage 0How data travels

  1. Packets and switchingSee why data is cut into packets, and why sharing a link packet by packet beats reserving it.12 min
  2. Delay and throughputBreak the time a packet takes into transmission, propagation and queuing, and see which one matters when.14 min

Stage 1Layers and devices

  1. LayersLearn the layers of the TCP/IP and OSI models, and what each is responsible for.13 min
  2. EncapsulationFollow a message down the sender's stack, gaining a header at every layer, and back up the receiver's.12 min
  3. Hubs, switches and routersSee what each device does with an arriving frame, and which layer it works at.12 min

All of Network basics is free

That’s the whole topic, from the first idea to the mastery stage, with no card needed. Create a free account to practise, keep your progress and carry on to the next topic.

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