Packet Encapsulation Simulator

Packet Encapsulation & Network Journey

See exactly how application data gets wrapped in headers at each OSI layer, and watch how switches, routers, and servers each interpret the resulting frame.

Frame Structure

Total Size: 0 B

Encapsulation

Each layer adds its own header around the data from the layer above, like nesting envelopes inside each other.

De-encapsulation

The receiver strips headers layer by layer, moving up the stack until only the original application data remains.

PDU Names

L7: Data · L4: Segment · L3: Packet · L2: Frame. Each layer's unit has a specific name — the Protocol Data Unit (PDU).

Device X-Ray View

Frame Inspection

Readable

🔒 Opaque / Locked

Switch (L2)

Only reads MAC addresses. Has zero knowledge of IP addresses, ports, or application data — everything above L2 is completely opaque.

Router (L3)

Reads L2 and L3 headers. Makes routing decisions based on destination IP. Rewrites MAC headers at each hop. Decrements TTL.

End Host (L7)

Strips all headers layer by layer, moving up the OSI stack until the raw application data (HTTP request) is exposed for processing.