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DevOps Guide: OSI Model Basics in Computer Networking

DevOps Guide: OSI Model Basics in Computer Networking

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Sagnik Das
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Hey there! I'm Sagnik, a MERN stack developer currently learning DevOps as well. I believe in learning in public, sharing my knowledge with the community, and learning from everyone involved. I'm writing my first blog post on a topic in computer networking.

OSI MODEL

  • The Open Systems Interconnection (OSI) is a reference model that explains how a software application transfers from one computer to another.

  • The OSI model comprises seven layers, with each layer performing a specific function.

  • OSI model divides the whole task into seven smaller and manageable tasks.

7 Layers of OSI Model

  1. Application Layer

  2. Presentation Layer

  3. Session Layer

  4. Transport Layer

  5. Network Layer

  6. Data Link Layer

  7. Physical Layer

Application Layer

  • This layer provides the network services to the end-users

  • It is the topmost layer

  • It serves as a window for users and application processes for the network service

  • This layer defines many application-level protocols such as HTTP for web browsing, SMTP for email, FTP for file transfer.

Presentation Layer

  • This layer acts as a data translator for a network

  • This layer handles character encoding.

  • It is a data encryption decryption layer

  • The Presentation layer is also known as the syntax layer

Session Layer

  • The Session layer is used to establish, maintain and synchronizes the interaction between communicating devices

  • Assign unique session IDs

  • Provides error detection and recovery

Transport Layer

  • This layer ensures that the messages are transmitted in the order in which they are sent

  • It converts the data into smaller segments

  • The protocols defined here are TCP ( Transmission Control Protocol ) and UDP ( User Datagram Protocol ).

Network Layer

  • It determines the best path to move the data from source to destination

  • It sends the received data segments from one computer to another computer that is located in a different network

  • Responsible for logical addressing and routing.

  • This layer is responsible for error free transfer of data frames

  • It defines the format of the data on the network.

  • The packet received from the Network layer is further divided into frames depending on the frame size of NIC(Network Interface Card).

Physical Layer

  • It is the lowest layer of the OSI model

  • It establishes, maintains and deactivates the physical connection

  • The physical layer contains information in the form of bits

So this is the article/blog. I hope you find it informative. If you like it please follow like and share. I will continue to write informative blog posts related to DevOps.Please give your feedback in the comments where i can improve .Thank You .

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