What Data Unit Is Associated With The Open Systems Interconnection Layer Four?

What data unit is associated with the open systems interconnection layer four?
The frame data unit is associated with the Open System Interconnection. Now, let us learn the different layers of the OSI model.

The OSI model is used to understand, how the data is transferred from one system to another system over the internet. To define in simple words, two computers that are connected to the LAN connection and through the RJ45 connectors and sharing the data through the network interface cable will form a computer network. But if one computer is based on the Microsoft window and the other computer is based on the MAC os, it makes it difficult for the computers to communicate with each other.

So to maintain successful communication between the two computers we use the OSI model. These OSI models consist of several layers. It is introduced by the ISO in the year 1984.
• Application layer
• presentation layer
• session layer
• Transport layer
• Network layer
• Datalink layer
• Physical layer
All these layers are the package of the protocols. Each layer consist of some of the protocols that help to communicate with the other layers.

Let us know the working of each layer in detail. The application layer is mostly used by network applications. Network applications are nothing but computer applications that uses the internet. The network applications use the application layer protocol like HTTP or HTTP in order to perform web surfing. There are many protocols that help for the functioning of the application layer protocol. File transfer, email, web surfing, virtual terminals are are performed at the application layer.

The presentation layer receives the data from the application layer, this data is in the form of numbers. It converts into the machine understandable language. The presentation layer can also be called the translation. Before transmitting the data, the data is get reduced by using data compression. During the data compression, it may lose the data or it cannot. It also performs encryption and decryption at the sender and the receiver side.

The next layer is the session layer that manages the connection. It enables sending and receiving of the data. The session layer consists of the APIs and NETBIOS for the basic input-output systems. It allows applications on different computers for communication.

The next layer is the transport layer that controls the reliability of the communication through segmentation, flow control, and error control.
The data that is received from the session layer is divided into the form of the data units called segments. each segment contains the source and the destination’s port number and the sequence number. The port number helps to direct each segment.

The transport layer sends the data segments into the network layer. The network layer works for the transmission of the received data segment from one computer to the other computer. The data units in the network layer are called packets.

The data link layer consists of two types of addressing, they are logical addressing and physical addressing. The logical addressing is done at the network layer and physical addressing is done at the physical layer. The mac address of the sender and the receiver are to each frame.