Application Layer – Layer 7
At the very top of the OSI Reference Model stack of layers, we find the Application layer which is implemented by the network applications. These applications produce the data to be transferred over the network. This layer also serves as a window for the application services to access the network and for displaying the received information to the user.
Example: Application – Browsers, Skype Messenger, etc.
Note: 1. The application Layer is also called Desktop Layer.
2. Device or Protocol Use : SMTP
Functions of the Application Layer
The main functions of the application layer are given below.
- Network Virtual Terminal(NVT): It allows a user to log on to a remote host.
- File transfer access and management(FTAM): This application allows a user to
access files in a remote host, retrieve files in a remote host, and manage or
control files from a remote computer. - Mail Services: Provide email service.
- Directory Services: This application provides distributed database sources
and access for global information about various objects and services.
Note: The OSI model acts as a reference model and is not implemented on the Internet because of its late invention. The current model being used is the TCP/IP model.
What is OSI Model? – Layers of OSI Model
OSI stands for Open Systems Interconnection, where open stands to say non-proprietary. It is a 7-layer architecture with each layer having specific functionality to perform. All these 7 layers work collaboratively to transmit the data from one person to another across the globe. The OSI reference model was developed by ISO – ‘International Organization for Standardization‘, in the year 1984.
The OSI model provides a theoretical foundation for understanding network communication. However, it is usually not directly implemented in its entirety in real-world networking hardware or software. Instead, specific protocols and technologies are often designed based on the principles outlined in the OSI model to facilitate efficient data transmission and networking operations.
Prerequisite: Basics of Computer Networking
- What is OSI Model?
- What are the 7 layers of the OSI Model?
- Physical Layer – Layer 1
- Data Link Layer (DLL) – Layer 2
- Network Layer – Layer 3
- Transport Layer – Layer 4
- Session Layer – Layer 5
- Presentation Layer – Layer 6
- Application Layer – Layer 7
- What is the Flow of Data in OSI Model?
- Advantages of OSI Model
- OSI Model in a Nutshell
- OSI vs TCP/IP Model