What is the connection of open systems?

Connecting open systems is a reference model that illustrates how messages should be transmitted via the telecommunications network. It does not include detailed interfaces. Instead, it serves as a wizard for network creators, so their products are compatible with products of other creators. The interconnection of open systems includes seven functions known as functional layers that should be carried out when messages are sent via the network.

This reference model was created by an international standardization organization (iOS). IOS is a group of representatives of more than 160 countries that strives to create standards to facilitate communication and business cooperation between countries. Recommendations for interconnection of open systems are coded in section X.200 International Telecommunication Union - telecommunications standards (ITU -TS).

Every computer in the network should be able to perform all seven functional layers. No one program performs all four functions. They are divided among several components of the computer instead. Functions can be performed by operating system, programs or network protocols.

Seven layers are divided into two groups. The first three are used every computer. These are physical, data and network layers. If the message is not intended for a computer, it passes through, but only uses the computer for transport, the messages do not pass through the other four layers. These layers are only used when the message moves from the user or to the user.

Physical layer allows hardware to send and receive data bits. The Open Systems connection layer is aware of the transmission protocol and ensures that the computer follows these rules. Finally, the network layer sends the data to the right computer. Much Like and Envelope Strices at the post office, dividing messages into outgoing mail designed for other computers and local mail designed for processing computer.

If the message is local mail isthen processed by four other functions of open systems. The transport layer ensures that the complete message has arrived and checks errors. Like the telephone operator in old movies, the session layer coordinates the connection between two computers. During the presentation or layer of syntax, data is converted from a format in which it was sent to a format that the computer can read. Finally, the application layer takes care of all small details, from the speed of connection speed to ensure privacy and authorization.