What is OSI Layer? It's Types

What is OSI Layer? It's Types

The OSI (Open Systems Interconnection) model is a way of describing how different devices communicate with each other over a network. It’s is developed by the ISO.

The OSI model is used in the field of networking to provide a standardized way of understanding how devices communicate with each other in a network. The OSI model is divided into seven layers, each with its own specific set of functions. These layers are arranged in a hierarchical order, with each layer building on top of the one below it. The seven layers of the OSI model are:

7. Application layer

6. Presentation Layer

5. Session Layer

4. Transport Layer

3. Network Layer

2. Data Link Layer

1. Physical layer

Note:

You can remember above point just like this All People Seen To Need Data Processing

A - Application Layer

P - Presentation Layer

S - Session Layer

T - Transport Layer

N - Network Layer

D - Data Link Layer

P - Physical Layer

 

Describe Above point in detail

7. Application Layer:

• Provides high-level services and protocols to end-users.
• Enables communication between software applications running on different devices.
• Defines protocols and standards for common applications to ensure interoperability between devices.  
• Implements protocols such as HTTP, FTP, SMTP, and DNS.
  Supports application-level services such as file sharing, email, and remote login.
• Supports application-level services such as file sharing, email, and remote login. 

6. Presentation Layer:

• Provides data representation and manipulation services.
• Translates data between different data formats and character sets.
• Handles data encryption, compression, and formatting.
• Enables data conversion between different data types.  
• Provides services such as data compression, encryption, and decryption.

5. Session Layer:

• Establishes, manages, and terminates communication sessions between devices.
• Provides synchronization and checkpointing, allowing devices to resume communication after an interruption. 
• Handles security and authentication of communication sessions.  
• Provides session management and control such as opening and closing sessions.
  
• Supports remote procedure calls and virtual terminal access

4. Transport Layer:

• Provides reliable and transparent data transfer between devices.
• Ensures data integrity, flow control, and error recovery.
• Manages connections between devices and multiplexing of data streams.
• Can provide segmentation and reassembly of large data sets.
•  Implements transport protocols such as TCP and UDP.
  

3. Network Layer:

•  Provides logical addressing and routing of data between devices on different networks.
• Determines the best path for data to travel between devices.
• Handles addressing and packet switching, as well as congestion control and traffic prioritization.
  
• Translates logical addresses into physical addresses.
•  Implements routing protocols such as RIP, OSPF, and BGP.

2. Data Link Layer:

• Transfers data between directly connected devices on the same network.
• Divides the data into frames and adds header and trailer information to each frame.
• Performs error detection and correction, flow control, and manages access to the communication medium.
• Provides MAC addressing to uniquely identify devices on the network.
• Defines the protocols for error recovery and retransmission of lost frames.

1. Physical Layer:

•  Transmits raw data bits over a communication channel using physical devices and media.
  
• Defines the specifications for physical connections, such as voltage levels, bit rates, and transmission distances.
• Handles the electrical and mechanical characteristics of the interface between devices, including the cables and connectors.
• Specifies the transmission mode such as simplex, half-duplex, and full-duplex.
• Provides physical addressing to identify devices on the network.