KKPI

Understanding the OSI Layer

The Open Systems Interconnection (OSI) was created by the International Organization for Standardization (ISO) which provides a framework of structured logic how the process interacts with the data communication network. Standard was developed for the computer industry to communicate on different networks efficiently.

There are seven layers of the OSI model. Each layer is responsible for a particular aspect of data communications. For example, one layer is responsible for establishing connections between devices, while the other layer is responsible for correcting the "error" during the process of data transfer.

The layers of the OSI model are divided into two groups: "upper layer" and "lower layer". "Upper Layer" focus on the user and how the application represented in the computer file. For Network Engineer, the main part of the focus is on "lower layer". Lower layer

is the essence of actual data communication through the network.

"Open" in the OSI network model is to declare that interconnect regardless of the hardware / "hardware" is used, all in accordance with the standard communications software. It is an indirect cause "modularity" (to be assembled).

"Modularity" refers to the exchange of a certain level protocols without affecting or damaging the relationship or the function of the other levels.

In one layer, protocol interchangeable, and allows communication to continue. This exchange takes place based on the hardware "hardware" from different vendors and a variety of different reasons or desires. Here are illustrated from the modularity

7 Layer OSI

The OSI model consists of seven layers:

7. Application

6. Presentation

5. Session

4. Transport

3. Network

2. Data Link

1. Physical

his job was

7.

Application Layer: Provides services to user applications. It is responsible for the exchange of information between computer programs, such as the e-mail, and other services running on the network, such as a print server or other computer applications

6.

Presentation Layer: how data is converted and formatted for data transfer. Examples of ASCII text format conversion for documents,. GIF and JPG for images. This layer performs code conversion, data translation, encryption and conversion.

5.

Session Layer: Determines how two devices establish, maintain and manage a connection - how they interrelate

each other. These connections are called "session".

4.

Transport Layer: Responsible for dividing data into segments, establishing an "end-to-end" inter-terminal, and provides error handling (error handling).

3.

Network Layer: Responsible for determining the network address, specify the route to be taken during the trip, and keeping network traffic congestion. Data at The packaged.

2.

Data Link Layer: Provides links to data, packaged into frames associated with the "hardware" and then transported through the media. It communicates with the network card, set the physical layer of communication between the system connection and error handling.

1.

Physical Layer: Responsible for process and transfer the data into bits through the media, such as cable, and keep the physical connection between systems.