Introduction

The Open Systems Interconnection Model (OSI Model) is a theoretical framework for describing the functions of a networking system. In order to facilitate interoperability between diverse devices and applications, the OSI model describes computing functions into a universal set of rules and standards. The connections between computing systems are divided into seven abstraction levels in the OSI reference model: Physical, Data Link, Network, Transport, Session, Presentation, and Application.

The OSI was published in 1984 by the International Organization for Standardization at a period when network computing was still in its infancy (ISO). The OSI Model is still used to explain network architecture today, even if it does not always map exactly to real systems.

The 7 Layers of the OSI Model

Physical Layer

The OSI Model’s lowest layer is concerned with electrically or optically passing raw unstructured data bits over the network from the sending device’s physical layer to the receiving device’s physical layer. Voltages, pin arrangement, cabling, and radio frequencies are examples of specifications. Network hubs, cabling, repeaters, network adapters, and modems are examples of “physical” resources found at the physical layer.

Data Link Layer

Directly connected nodes are utilized at the data connection layer to perform node-to-node data transfer, in which data is bundled into frames. Errors that may have happened at the physical layer are also corrected by the data link layer.

Network Layer

Receiving frames from the data link layer and delivering them to their intended destinations based on the addresses contained within the frame is the responsibility of the network layer. Logic addresses, such as IP addresses, are used by the network layer to locate the destination (internet protocol). Routers are a critical component at this tier, as they literally route data where it needs to go between networks.

Transport Layer

The transport layer is in charge of data packet delivery and error checking. It controls the size, sequencing, and, ultimately, data transit between systems and hosts. TCP, or Transmission Control Protocol, is one of the most frequent transport layer instances.

Session Layer

The session layer is in charge of coordinating conversations between computers. At layer 5, a session or connection between machines is established, managed, and terminated. Authentication and re-connections are also part of the session layer services.

Presentation Layer

Based on the syntax or semantics that the application accepts, the presentation layer formats or converts data for the application layer. As a result, it’s sometimes referred to as the syntactic layer. This layer can also handle the application layer’s encryption and decryption needs.

Application Layer

Both the end user and the application layer interact with the software application directly at this tier. End-user programmers, such as a web browser or Office 365, receive network services through this layer. The application layer locates communication partners, determines resource availability, and coordinates communication.

Conclusion

The theoretical OSI Model is used, on a daily basis, throughout the industry as it is an essential building block for when it comes to creating and troubleshooting applications and infrastructures. Follow the data down the layer to see how it’s transported and handled by systems and networks.

Introduction

Human communication and computer communication are very similar. Many parts of computer science are, in fact, comparable to human behavior. If you’re interested in learning how these machines communicate with one another and how data flows through a network, this article is for you. If computers appear to be a fascinating subject for your thinking, computer communication may pique your interest.

Before we go into computer communications, let’s have a look at the article’s structure. The first few paragraphs give an overview of computer systems. Following that, we’ll go over more technical topics like computer networking and network protocols.

Computers Connect with One Another using Their Own Network

On a daily basis, we use the internet. This essentially indicates that we’re all part of the same network. The Internet is a global network that connects all of the world’s users, allowing them to communicate with one another at any time and from any location because they are all members of the same network. A network is a collection of interconnected devices. It can also be a collection of smaller networks. A computer network is made up of two or more computers connected through a network media. Users on the same network can share the same hardware (a printer) and software (apps) and send various types of data such as text, video, and audio. Hardware is employed to connect them, such as the

There are two different sorts of networks. Local area networks and wide area networks are the two types. The key distinction is the network’s range of connectivity. Let’s start with a basic definition of what a local network is.
Because it is established locally, the LAN (Local Area Network) may connect a smaller number of computers, as its name suggests.

You could conceive of a local network as a system that connects people who share a common interest, such as computers in a classroom to allow students and staff to communicate, or computers in a business. The LAN can be a secure network that only they can access and use. As a result, the LAN now has authorized users who use their IP addresses as indicated below.

The network’s identification of the sender and recipient is also detailed below.
Let’s have a look at the wide area network now. The Wide Area Network (WAN) can be used to construct a larger network than the LAN as the number of users grows. The WAN is a network that links networks over wide geographical areas. Assume that the company has expanded its offices to other countries or locations and that they still wish to connect with one another. The Wide Area Network (WAN) is used to carry data over great distances or between networks that are connected to a larger one. Because of the number of users and complexity, WAN speeds can be slower than LAN speeds, however this is dependent on the settings.

What method does the network use to determine which computer is the intended recipient?

We’ve already established a LAN. We can join all of the machines in the same network with a single Ethernet connection. When computer A (or a user) wants to send a message to computer B, the message travels over the cable and is received by all computers in the network because they all share the same medium.

But how does the network know who the message is intended for?

The message is destined for a reader who is eager to read it and is likely to wish to exchange information in return. The router utilizes the MAC address of each machine to resolve this issue. This address ensures that the physical address of the machine is unique.

The Internet Protocol facilitates data transmission within a network. Network packets are used to send the data. A static IP address and a public IP address are assigned to each computer.

Your machine has its own private IP address. Your gadget is given an address by your ISP (Internet Service Provider). The router saves this IP address. A routing table is stored on the router and contains all of the private IP addresses (mobile, laptop, etc.) that are connected to this network.

Summary

The principles of computer communications are covered in this article. You now understand how data is transferred from a wire as a signal to another computer in readable form, going through several levels and protocols. When you press the Send button, the data (signal) becomes 01010101, which passes through the OSI model’s multiple layers