OSI Layer: Definition, 7 Layers & How They Work

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 Communicating in this era is getting easier and not as difficult as in the past.

 In the past, to perform a data exchange for communication from one computer to another is very difficult.

 Everyone still uses letters, the development of the communication era has made progress with telephone services.

 After a few years later the new internet was discovered.

 History of OSI Layer

 Before the OSI layer was discovered, each vendor or developer had their own network protocols that were different from one another.

 So to be able to communicate with each other is very difficult, even though both are on the same network.

 In the 1980s, a body called the International Organization for Standardization then made a reference model and named it OSI.

 OSI has 7 layers which of course all have various functions of each.

 However, for a clearer understanding of the meaning, 7 OSI layers and so on, you better refer to the discussion below!

 What are OSI Layers?

 Open Systems Interconnection or OSI is a reference model which is created in the form of a conceptual framework.

 Even today it has become a connection standard for a computer.  In addition, it was created also to fulfill a specific purpose.

 The goal is that the OSI model becomes a reference for every vendor or developer so that the software and products they make have an interpolate nature.

 This means that users don't have to make special efforts and they can cooperate with the system or product.

 7 OSI Layers and Their Explanations

 If you have a question, how many layers are there in OSI Layers?  The answer is there are 7 layers.

 In OSI itself there are 7 layers of OSI layers and their functions have their respective roles.

 What are the seven OSI layer sequences in question?  Here's the explanation for you!

 1. Physical Layer

 You could say that this physical layer is the most important.  The responsibility of this OSI layer is in terms of transmitting data bits.

 Of course this is done from the sending physical layer and addressed to the receiving physical layer.

 Later here the data will also be transmitted using the type of signal that has been supported by physical media.

 Say like a cable, electric voltage, radio frequency or it could be infrared and ordinary light.

 2. Data Link Layer

 When the data transmission process is in progress, there will be potential for errors to occur.

 So this is the responsibility of the OSI data link layer service layer where its job is to do error checking.

 The data link layers in the OSI sequence also have the responsibility of wrapping the bits into a data frame.

 In addition, the data link layer can also manage physical observation schemes such as MAC addresses on a network.

 You could even say that this data link layer is one of the most complex among the other layers.

 This is the reason the data link layer is divided into 2 sublayers, namely MAC (Media Access Control) and LLC (Logical Link Control).

 The task of the MAC itself is none other than controlling which devices from a network have access to the medium and also permissions when transmitting data.

 While the LLC itself is in charge of identifying and then wrapping network layer protocols and also controlling error checking.

 3. Network Layer

 Among the 7 existing OSI layers, the OSI layer used for the routing process is the network layer.

 This makes each computer finally able to connect to 1 network.

 Not only that, the network layer also functions to perform the routing process and create headers for existing data packets.

 4. Transport Layer

 The 4th level of the OSI layer is the transport layer.

 For sending messages between 2 or more hosts on the network, this is the responsibility of the transport layer.

 In addition, it also handles the splitting and merging of messages and then also performs control for the reliability of the connection path that has been given.

 5. Session Layer

 The responsibility of the session layer is to control the session connection dialog and also manage and even disconnect from the computer.

 In order to form a communication session, a virtual circuit is used which is created by the OSI layer called the transport layer.

 6. Presentation Layer

 Define the syntax used by network hosts in communicating is the task of this presentation layer.

 OSI layer number 6 is also responsible for encrypting and also describing information and data so that it can then be used at the application layer.

 7. Application Layer

 Talking about providing interfaces between network protocols in applications that already exist on the computer, then this is the task of the Application layer.

 It is also the top layer of the OSI model and often provides the services that applications need most.

 Those are the 7 OSI layers and their explanations that might be useful for you.

 In addition to understanding the meaning of 7 layers, now we will also discuss how the OSI model works.

 How OSI Layers Work

 How OSI Layers Work

 How the OSI layer works can be said to be very long and quite complicated.

 Take for example when you want to send an email to another computer.  Here are the steps:

 Application layer sends data to other computers

 Presentation layer converts email to network format

 The session layer forms a data journey session until the sending process is complete

 The sender transport layer breaks down the data and collects it again at the receiving transport layer

 The network layer creates an address and guides data to its destination

 The data link layer then shapes the data into frames and physical addresses

 Then at the physical layer the data will be sent over the network medium to the receiving transport layer

 After that the flow reverses from the physical layer to the application layer on the receiving computer

 That's an explanation of the 7 OSI layers and how they work.  Hopefully the above information can add to your insight