2.3. OSI Networking Model

The Open Systems Interconnection (OSI) model characterizes every one of the strategies and conventions expected to interface one PC to whatever other over a network. It is an applied model, utilized regularly as a part of network configuration and in designing network arrangements. For the most part, true networks fit in with the OSI model, in spite of the fact that distinctions exist between the hypothesis and genuine practice in many networks. Still, the OSI model offers an astounding approach to comprehend and imagine how PCs network to each other, and it is required information for anybody dynamic in the field of networking. Pretty much all businesses anticipate that networking experts will be proficient about the OSI model, and it comes up on most networking certification tests. This may be an extremely dry topic, yet it's vital to learn!

The OSI model characterizes a fundamental structure for how cutting edge networks work. It isolates the techniques and conventions required for a network association into seven distinctive layers. Each upper layer depends on services gave by an inferior layer. If you somehow happened to consider a desktop PC along these lines its equipment would be the lowest layer, and the OS drivers—the next higher layer—would depend on the least layer to carry out their employment. The OS itself, the next higher layer, would depend on both of the lower layers working legitimately. This proceeds with as far as possible up to the time when an application presents data to you on the PC screen. Figure 2.3 demonstrates the seven layers of the OSI model.

For a complete network association, data streams from the top layer on one PC, down through all the lower layers, over the wire, and go down the seven layers on the other PC. The accompanying areas examine every layer, making correlations with genuine networking frameworks as suitable.

Figure 2.3. The seven layers of the OSI model