Types of OSI Model Layers

As a tech expert, I have worked closely with the OSI model and layers to make it easier for individuals to transfer data and information from one computer to another. This is a seamless way of data transfer that also ensures data security. The OSI model is made up of seven layers and each of the layers has certain distinct features that help the system to perform various network functions.

I have curated this detailed tutorial for you to better understand the different layers in OSI model as well as the function of OSI model in this ever-evolving technological era.

What is the OSI Model?

The Open System Interconnection model, as the name suggests, is an abstract structure that makes it possible for different systems of communication to interact using common standard protocols. In simple words, the OSI paradigm offers a norm that allows various computer systems to link and share information.

Here, I am attaching a descriptive OSI model diagram that will help you to better understand what the structure is about and how it actually works. The OSI model was developed by the International Organization for Standardization in 1984 with an aim to allow a variety of communication systems to interact with each other by employing certain standard protocols, also known as OSI model layers protocols. This model consists of seven descriptive layers that together make up the means to interact across a network.

7 Layers of the OSI Model

This architectural model splits the assignment into seven simpler and manageable sub-tasks. Different layers in the OSI model have a specific task entrusted to it. Since every layer is standalone, tasks allocated to each layer can be handled and accomplished on their own.

Now that you are well-versed in the concept and significance of the OSI model, let me walk you through the different OSI model layers with examples.

Application Layer

The application layer in OSI model allows users and software operations to access network services. In my years of experience, this layer has dealt with concerns like allocation and distribution of resources, network transparency, seamless transmission of data, and so on.

However, the software applications are not inclusive of this layer. The application layer only assists you in carrying out application layer activities. It is the final users who acquire the network amenities through this layer. Application layer protocols encompass both HTTP and SMTP signals that permit communication via email.

In my early days in the tech field, the most important function of the application layer that I experienced was its ability to allow users to access, manage, and transfer files on a remote computer. This layer also allows users to forward and store email.

Presentation Layer

The presentation layer is popularly known as the syntax layer. This layer mostly deals with the Sintic and semantic components of the data communicated between two computer systems. The OSI model security architecture greatly depends upon the presentation layer as it operates as the data interpreter of a network.

The OSI model uses the data prepared by the presentation layer. You can make the presentation layer as secure as possible by encrypting the data that you want to transmit to another device.

Session Layer

This is the third layer in the OSI model, which is primarily used to build, sustain, and coordinate the interaction between two or more devices. This layer is in charge of establishing and terminating communication among the devices. The session layer, as the name suggests, denotes the period of time between the start and completion of a communication to avoid the wastage of resources.

This particular layer will allow you to remain in session for a communication and it will end the communication after the transmission of data.

Transport Layer

The OSI model, transport layer is one of the most crucial layers in the entire structure. Earlier I used to find it very difficult to understand the mechanism of this layer. Hence, I am explaining the functionalities of the transport layer in the easiest manner.

This layer guarantees that there is no redundancy of data and that the messages are dispatched and delivered in the particular sequence as they were sent. The primary responsibility of the transport layer is to ensure that the transmission of information is done properly and completely. Whenever you try to send a message, this layer breaks it into smaller segments and sends it in a sequence.

This layer is popularly known as end to end layer because it builds a dependable point-to-point connection between the place of origin, origin, and destination in order to transmit the data.

Network Layer

The network layer in OSI model keeps track of the location of various devices on a particular network. This is done so that your system can find the best path through which it can move the data packets from one system to another.

It helps decide the path via which the data will travel from the source to the destination. This layer also converts the information into small data packets which makes it easier to travel through the route channels.

Data Link Layer

The data link layer in OSI model has the duty to monitor and ensure error-free transmission of data. This layer builds trust and reliability in the communication channel between two or more computer systems.

This data layer in OSI model helps uniquely identify and locate every device existing on the given local network. This layer defines the hardware destination and the address of the originator.

Physical Layer

The physical layer, also layer 1 of the OSI model transmits small bits from one node to another. This is regarded as the lowest layer in the OSI model that sets up, promotes, and terminates the physical connection.

It specifies the necessities associated with the procedural and mechanical network connections. Throughout these years, the physical layer has mostly assisted me in deciding the kind of signal that I should use while transferring data.

OSI vs TCP Model

We know the TCP/IP model as a new-age model which handles communication over the Internet. However, the OSI model is quite different from the TCI model.

Let me illustrate the differences between the OSI model and TCP/IP model:

Summing Up

Having worked so many years in the tech industry, I can say that the OSI model has genuinely helped me to work around network communication. Although it is incompatible with the Internet, it still has helped me a lot in understanding how communication within a network should be conducted.

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Frequently Asked Questions

1. Is the OSI Model still relevant today?

The TCP/IP model serves as the foundation of Internet programs as opposed to the OSI model. However, the OSI model is still used for facilitating communication and visualization of network processes.

2. Are there any limitations to the OSI Model?

The OSI structure has several drawbacks such as it is incompatible with the Internet, it does not back Internet-based protocols and applications such as HTTP, TCP, IP, UDP, etc.

3. What is the purpose of the OSI Model?

The OSI model serves as a handbook and a universal language to define computer networking. It offers a foundation for various computer systems to be able to interact with each other.

4. What are some examples of protocols that operate at the Network Layer?

The major used protocols at the network layer are IP and ICMP. Apart from these two, there are certain other protocols such as address resolution protocol, domain name system, border Gateway protocol, etc.

5. How does the OSI Model handle data transmission errors?

To explain the OSI model, it is important to know its capability of handling data transmission errors. The transport layer uses an error detection approach and correction methodology to make sure that the data is safe and secure during transmission.

6. How many layers are in the OSI model?

There are a total of seven layers in the OSI structure that provide a detailed approach to networking and communication.

7. Why is the OSI model used?

The OSI model combines computing operations into an integrated set of rules and standards in order to encourage portability and connectivity throughout different software and hardware components.

8. What are the 7 network protocols?

The are numerous network protocols, but the seven most common ones include, Hypertext Transfer Protocol (HTTP), Internet Protocol (IP), File Transfer Protocol (FTP), User Datagram Protocol (UDP), Simple Network Management Protocol (SNMP), Internet Control Message Protocol (ICMP) and Post Office Protocol (POP).