Layering

Last updated May 26, 2023 Edit

# Concept of layering

Layering is the process of breaking a complex process into several processes or layers in a particular order.
Layers help to solve a complex problem by dividing into a set of simple layers.

This layer is responsible for ensuring that the data supplied by the sender from their application can be viewed by the receiver’s application.
These applications allow the user to access emails, websites and perform file transfers.

The data from the application layer is divided into various segments in the transport layer at the sender’s side.
The various segments are called packets.
Each packet also contains a header that denotes the total number of packets, packet number and port number.
The port number reflects the protocol
If any packets go missing during transmission, the transport layer is where a resend will be handled (TCP only).
Windowing happens at this point
TCP/UDP exist at this layer.

Internet layer adds the sender’s and receiver’s addresses in the data packet.
Using the information, this layer routes the data packet from the sender to receiver.
A socket specifies to which device the data packet must be sent to and to what application it was sent from.

Link layer deals with the physical connectivity between sender and receiver.
The Network Interface Card (NIC) of any device is uniquely identified using its MAC address.
Link layer adds the MAC address of the sender and the receiver to the network address.
Now the data is streamed to the correct hardware device.
This layer is also responsible for error detection, hardware addressing, media access control and defining physical layer standards.

Each layer of the TCP/IP stack adds information to the data. This is called encapsulation.