The Digital Data Network - OSI model

Our digital data networks and digital applications operates using the open systems interconnect (OSI) model. The OSI model is a framework with seven distinct layers and each layer has its own use in communicating data back and forth between the user device and application.

The OSI layers help understand how the data is transmitted between various layers. Understanding the layers help in taking care of all the seven layers as well as diagnose issues.

The OSI model layers

The OSI model came to existences in 1980s and since then remained in use. The OSU model has seven layers, namely Physical, Data Link, Network, Transport, Session, Presentation and Application.

Let’s understand each layer and it use,

Application Layer -?The Application Layer is the layer used by the user. At this layer the user enters the information or places the request or command through the device. E.g., use of web browser for searching. The application layer does the work of sending inputs (query) to other layers and receiving the outputs (results) to show to the user.

Presentation Layer -?The Presentation Layer is does the translation of data received from application layer. Data encryption and decryption takes place at the presentation layer. Presentation layer translates and encrypts the data to be sent to next layer and it also decrypts and translates the data to be sent to the application layer.

Session Layer –?The session layer is the bridging connection between devices (e.g., PC and Web Server). The session layer does the task of establishing secured connection for transmitting and receiving the data, to and from presentation layer to transport layer.

Transport Layer –?The transport layer decides and coordinates the amount of data to be transmitted from source to destination. The transmission control protocol (TCP) and user datagram protocol (UDP) is operated at the transport layer. How much of data to be transmitted and at what speed is decided at?

Network Layer –?The network layer is the layer that operates at the routers and hub. This layer handles the packet forwarding work that involves handling transfer of packets of data from routers to routers, routers to hubs etc. The network layer identifies what route to take to get the packets delivered to the next layer.

Data Link Layer –?the data link layer handled node to node data transfer and handles error corrections from the physical layer. It consists of media access control (MAC) and logical link control (LLC) layers. The switches in the network operate at data link layer as they connect the nodes.

Physical Layer –?The physical layer represents the physical parts of the system. It consists of network cable, radio frequency, pins and power supply etc. For problem solving we normally look for physical parts issues first before going to other layers.

Importance of the OSI Model

OSI model is important for digital product creators, application developers, and network teams as it helps understand the communication layers involved and how each layer functions.

OSI model gives clear understanding of how the data moves between layers from user device to the application hosted in a data centre and back to the user.?

Here is a quick overview of the seven layers usage.

Each of these seven layers must be made fully secured both physically and with software technology to reduce cyber security risks.

OSI model gives good understanding of how application and data centre migrations can be handled.

By understanding the Digital Data Network - OSI model and its seven layers, one can understand what protocols and digital devices can operate together and how to use them to enhance user experience, security and efficiency and effectiveness.

The Digital Data Network - OSI model is in use for the next generation digital networks and it remains highly relevant as a framework, for creating a good understanding of how digital data flows through various layers and what needs to be taken care at each layer to keep the digital solution secured.