Do you want to know the OSI model, those 7 layers, and their purpose?
If yes, then you have come to the right page!
A conceptual framework known as the Open Systems Interconnect (OSI) model divides networking or telecommunications systems into seven layers, each of which has unique features.
The OSI model divides a complex computer networking system into multiple different layers based on the functions that networking protocols perform. It is easier to troubleshoot issues, identify security threats, and assess network-layer hacks with this classification.
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There are two major layers in the OSI model: upper layers and lower layers.
The application-related problems that are mostly handled by the higher layer of the OSI model are limited to software implementation. The layer nearest to the user is the application layer. Software applications are interacted with by both the application layer and the end user. The layer just above another layer is referred to as an upper layer.
The OSI model’s lowest layer handles data transport-related concerns. Hardware and software are used to implement the data link layer and the physical layer. In the OSI model, the physical layer is the lowest layer and the one nearest to the physical medium.
The 7 layers of the OSI Model are listed below:
- Physical Layer
- Data-Link Layer
- Network Layer
- Transport Layer
- Session Layer
- Presentation Layer
- Application Layer
The Physical Layer
The primary function of the physical layer in the OSI model is to transfer the individual bits from one node to another. It is the lowest layer that maintains and deactivates the physical connections. The functions of the physical layer involve line configuration, topology, data transmission, and signal
The Data Link Layer
The data link layer is responsible for defining the data format on the network. It enables efficient and reliable communication among two or more devices. It has two sublayers-
- Logical Link Control layer
- Media Access Control Layer
The Network Layer
The network layer manages the device address while tracking the device’s location on the network. Along with this, it determines the best path to transfer data from source to destination by considering the network conditions. The functions of the network layer involve, interconnecting, addressing, routing, and packetizing.
Transport Layer
The transport layer is also known as the first of four “host” layers. This layer controls how data is transmitted between nodes, making sure all the errors are resolved and data is transferred in the right order. This is the layer where Transmission Control Protocol (TCP) functions.
Session Layer
It is the 3rd layer of the OSI model, which also maintains sessions between nodes. Setup, authentication, termination, and reconnections are all the functions of the session layer. The major functions of the session layer involve-
- Dialog control
- Synchronization
Presentation Layer
The primary function of the presentation layer is to convert network data into the formats required by an application. It works as a data translator for a network. The major functions of the presentation layer involve transaction, encryption, and compression of data.
Application Layer
The major functions of the application layer involve FTAM (File transfer, access, and management ). It also handles the functions such as resource allocation and network transparency.
