What is de-encapsulation and how does it work?

De-encapsulation is the reverse of encapsulation: as data moves up the stack at the receiver, each layer strips off its own header (and trailer) until the application gets a clean data stream.

* Each layer strips its own header going up the stack at the receiver. *

Process (receiving):

1. Received as Bits (Bit Stream)
2. Data Link layer removes frame header/trailer → Packet
3. Network layer removes network header → Segment
4. Transport layer removes transport header → Data (Data Stream)
5. Application processes the Data

Physical:    Receives BITS
Data Link:   Removes frame header/trailer → PACKET
Network:     Removes IP header → SEGMENT
Transport:   Removes TCP/UDP header → DATA
Application: Processes DATA

Key point: When a layer completes its process, it strips off its header and passes the data up to the next level until it becomes a data stream the application can process.

Analogy: Like unwrapping a package — tear off the wrapping, open the box, take the letter out of the envelope, then read it.

Go deeper:

• Encapsulation (networking) — de-encapsulation is the reverse process described here.
• The OSI Model — Practical Networking — shows headers being stripped as data climbs the stack at the receiver.