Once the rules are established, the data transfer phase begins. These applications produce the data, which has to be transferred over the network.

Another aspect of the Physical Layer is that it specifies the electrical characteristics of the signals used to transmit data over cables from one network node to another. Physical Layer. In this lesson (Seven Layers of Open Systems Interconnection (OSI) Model), you have learned what are the Seven Layers of Open Systems Interconnection (OSI) Model and the functions of these seven layers. The OSI Model isn’t itself a networking standard in the same sense that Ethernet and TCP/IP are. eval(ez_write_tag([[970,250],'omnisecu_com-banner-1','ezslot_6',150,'0','0'])); In practice, Session Layer is often combined with the Transport Layer. Layers 5,6 and 7 can be are thought of as the user support. It is the Hardware layer. In this case, a Network Layer device called a router forwards the packet to the destination network. Open Systems Interconnection (OSI) model categorizes these hundreds of problems to Seven Layers. The name of this layer is a little confusing because application programs (such as Excel or Word) aren’t actually part of the layer. If they did, they’d be working at the Data Link Layer, not at the Physical Layer. The Transport Layer is the basic layer at which one network computer communicates with another network computer. For example, if we select to compress the data from a network application that we are using, the Application Layer will pass that request to the Presentation Layer, but it will be the Presentation Layer that does the compression.

Layers 4–7 are sometimes called the upper layers.

In the connection establishment phase, the service and the rules (who transmits and when, how much data can be sent at a time etc.) The Data Link Layer is logically divided into two sublayers, The Media Access Control (MAC) Sublayer and the Logical Link Control (LLC) Sublayer. Transmission media stays outside the scope of the Physical Layer and are also referred to as Layer 0 of the Open Systems Interconnection (OSI) Model. The OSI Model isn’t itself a networking standard in the same sense that Ethernet and TCP/IP are. **Application Layer is also called as Desktop Layer. Port numbers identify the originating network application on the source computer and destination network application on the receiving computer. The network layer is responsible for working with logical addresses. This layer also serves as a window for the application services to access the network and for displaying the received information to the user.

Rather, the OSI Model is […] If network communications need to happen without any trouble, many problems must be solved. Writing code in comment? Coordinating all these problems are so complex and not easy to manage. OSI stands for Open System Interconnection is a reference model that describes how information from a software application in one computer moves through a physical medium to the software application in another computer. Routing comes into play when a computer on one network needs to send a packet to a computer on another network. The Logical Link Control sublayer is responsible for synchronizing frames, error checking, and flow control. This message or so-called Data is compressed, encrypted (if any secure data) and converted into bits (0’s and 1’s) so that it can be transmitted. They deal with the mechanics of how information is sent from one computer to another over a network. Routers, which are special computers used to build the network, direct the data packet generated by Network Layer using information stored in a table known as routing table.

The Transport layer handles transport functions such as reliable or unreliable delivery of the data to the destination.
To make this work correctly, incoming data from different applications are multiplexed at the Transport layer and sent to the bottom layers. The Logical addressing system used in Network Layer is known as IP address. The Presentation Layer also can scramble the data before it’s transmitted and then unscramble it at the other end, using a sophisticated encryption technique. Following image shows the data flow in OSI model, when network communication happens between two computers.


can be interpreted on the other side. It is responsible for transmitting individual bits from one node to the next. By using our site, you This is where the concept of logical addressing comes in; a logical address gives a network device a place where it can be accessed on the network — using an address that you assign.