TCP/IP OSI model war

Alright, folks — if you're someone like me, still figuring out how a message sent from your phone magically lands in someone else's inbox across the globe, congrats! You're diving into networking today.

In today’s study, I tackled the real foundation of how data flows, yeah! we’re talking about the TCP/IP and OSI models. You might've heard of them in lectures and gone “umm...?” — but trust me, after this read, you’ll be like “Dude, I get it!”

It was believed that back in early days devices could connect to each other but it was only possible through a common protocol the common set of protocols refers to TCP or OSI

TCP and OSI models were made into serious debate which to implement

The osi remains standard ones for the network engineers

Why These Models Even Exist?

Imagine a bunch of systems trying to talk but speaking different languages — that was the internet before these models showed up.

Protocols were introduced to standardize the way devices communicate. That’s where the OSI and TCP/IP models come in.

TCP/IP Model — war hero yet not (4 Layers Only)

The TCP/IP model is what we actually use in real-life internet communication. Let’s break it down — layer by layer.

1. Link Layer

Think of it as your local gossip zone. This layer handles everything from wires, switches, MAC addresses — anything that connects devices physically in your local area.

2. Internet Layer

This is the Google Maps of networking. It figures out the route your data should take. IP addresses live here — they’re like home addresses, guiding data to the right destination.

3. Transport Layer

Okay, this layer is my favorite. Picture two delivery guys:

TCP: The responsible guy. He knocks, waits for you to open, hands the package, even asks for a signature (reliable).

UDP: This guy just throws your package over the gate and leaves (fast, but not guaranteed).

Both are part of the Transport team, handling how the message gets delivered.

4. Application Layer

This is where you, the user, exist. Apps like Instagram, Gmail, and YouTube work at this level. Protocols like HTTP, DNS, and FTP chill here. It’s the party room for actual internet services.

OSI Model The Theory Master (7 Layers)

Now, the OSI Model is what textbooks worship. It’s more detailed, but trust me — it’s worth understanding because it helps in troubleshooting and explaining stuff clearly.

Here’s the 7-layer breakdown:

1. Physical Layer

Electric signals, cables, connectors — literally 0s and 1s being transferred as voltage. This is the backbone.

2. Data Link Layer

Here comes MAC addresses and switches. This layer ensures data doesn’t crash into someone else’s lane. It’s the local traffic cop.

3. Network Layer

This layer gives out IP addresses and decides where to send data. Routers work here. It’s the world tour guide for data.

4. Transport Layer

Again, our delivery boys — TCP and UDP.

TCP ensures your message reaches correctly, even if it has to resend parts.

UDP is speed king — no time to check if you got it.

5. Session Layer

Handles sessions — like keeping a Zoom call alive. No session = no chat.

6. Presentation Layer

Ever wondered how images, text, or emojis show up perfectly on every device? This guy formats the data. Also handles encryption/decryption.

7. Application Layer

Finally, the front-end of networking. Where you click, scroll, and use services like HTTP, SMTP, or DNS. What you see is what this layer shows.