Computer Networking

The OSI and TCP/IP Models, Without the Memorization

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Hand-drawn illustration of the OSI and TCP/IP models showing a banking app login traveling from a smartphone through a router, internet, and network layers to bank servers.

Network Guide · Level 1: Foundations · Lesson 2 of 21 A ticket lands on the help desk: My banking app says it can’t connect. Two technicians pick it up. One starts guessing—restart the phone, reinstall the app, blame the bank. The other asks a better question: Which layer is broken? Ten minutes later, only … Read more

What Actually Happens When You Open Your Banking App? The client-server model, packets, the big picture.

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What happens when you open your banking app showing the network journey from phone through DNS, internet, TLS, firewall, load balancer, and bank servers

Network Guide · Level 1: Foundations · Lesson 1 of 21 You tap your banking app on the bus, and about a second later your balance appears. So what happens when you open your banking app? A lot more than it looks like. Short answer: when you open your banking app, your phone gets an … Read more