What is layered architecture in networking?

Overview

For smooth data transmission, you need a very organized strategy because, in a network, many users transmit data simultaneously from one to another. An efficient approach is what allows users to send/receive data in an efficient and orderly manner. This strategy is implemented in computer networks, using different architecture and models and layered architecture is one of them.

Layering

The grouping of relevant communication functions into different hierarchical sets is known as layering. Every batch of operations is a separate layer.

Functions of layers

Each layer is responsible for the following functions:

• Perform a subset of different functions required for communication.
• Provide the services of its functions to the next higher layer in the hierarchy.
• Implementation of communication protocols with peer layers in another system.
• After implementing its operations, it relies on the next layer to perform additional functions.

Motivation of layering

There are many reasons to use layering in communication, but some of them include:

• Modularity
• Reusability and controllability

Modularity

It decomposes a significant problem into multiple small subproblems that can be managed easily. This gives you more flexibility in designing, modifying, and evolving the computer network. In simple words, it decreases complexity.

Reusability and controllability

It's a standard layering functionality; the lower layer can be shared with many upper layers, increasing the reusability and controllability because of the segmentation of functions. The layering can support incremental modifications easily.

Layered architecture

The architecture of computer networks uses a layering mechanism in which data transmitted from one defined layer to another for processing is a layered architecture.

There are three major fundamental components of layered architecture:

• Service: A collection of functions provided by a layer to a higher layer.
• Protocol: A set of rules to share data with the peer layer.
• Interface: This is a means of transmitting a message from one layer to another.

The application of layered architecture

Layered architecture is used for communication. There are two network models which use layering.

• OSI model
• IP/TCP model

There's a correspondence between these models, and TCP can be explained in terms of the OSI model. Layers can only communicate in two modes:

Vertical communication

The communication between adjacent layers requires mutual understanding of the services and information that the lower layer needs to provide to the upper layer.

Horizontal communication

This is the communication between hardware or software that is running on the same layer but on different machines.

Note: Communication between processes is done virtually through a medium.