Packet Journey
What happens when a data packet is sent? Follow a packet's journey from your browser to a web server, layer by layer.
01Scenario
You want to visit a website. You type "example.com" in your browser.
02What the packet contains
HTTP
GET Request
The browser constructs a GET / HTTP/1.1 request. This is application layer data — the actual content the packet will carry.
Request headers
Host: example.com
Port: 443
Method: GET
Position in the stack
- Layer 7 — Application data
- Ready to be handed down
03Journey steps
L7 · Application
HTTP request is created
L4 · Transport
TCP
TCP segment created · Port 443
L3 · Network
IP
TCP
IP packet created · 192.168.1.5 → 93.184.216.34
L2 · Data Link
ETH
IP
TCP
Ethernet frame · MAC → Router MAC
L1 · Physical
101010101010... → Sent over cable or air
04Summary
- HTTP request → TCP segment → IP packet → Ethernet frame → Bits
- Each layer adds its own header (encapsulation)
- At the destination the process reverses (de-encapsulation)