Hello, everyone!
Today, I continue to explain network communication. Now, I will shortly explain ISO/OSI referent model, TCP/IP model and the differences between these two models. Let’s get started.
Since 1960, the rapid development of computers and computer networks has begun. There was an incompatibility of devices, so in 1984. the International Organization for Standardization (ISO) developed the OSI (Open System Interconnection) reference model to help manufacturers. So very quickly, the OSI reference model has become the basic model in network communication.
Figure 1. OSI vs TCP/IP
The TCP/IP (Transport Control Protocol/Internet Protocol) model is a set of standards that enable network communication. In figure 1, we can see the difference between OSI and TCP/IP models.
The OSI model has 7 levels:
Application - layer 7
Presentation - layer 6,
Session - layer 5,
Transport - layer 4,
Network - layer 3,
Data Link - layer 2 and
Physical - layer 1.
TCP/IP model has 5 levels:
Application - layer 5,
Transport - layer 4,
Network - layer 3,
Data Link - layer 2, and
Physical - layer 1.
OSI is intended for open systems, TCP/IP is for control transmission. OSI looks vertically, TCP/IP looks horizontally. OSI works only connection-oriented, on the other hand, the TCP/IP model is both connection-oriented and connectionless.
Figure 2. TCP/IP protocol stack
TCP/IP comes from two main protocols, TCP (Transport Control Protocol) and IP (Internet Protocol). This model is a set of communication protocols. Each layer of this model defines special protocols.
Details of all these protocols will be in the following articles. In the picture above, we can see the TCP / IP protocol stack - you can see the levels and some of the protocols. This is very important to understand well.
This is the end of this article. In the next article, I will continue to write about this topic >> Network communication basics (3).
Thank you!
