Osi Model

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Submitted By wolfrose
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OSI Model
The Open Systems Interconnection (OSI) reference model is a way to standardize communication between networked computers and other devices. Since there are so many ways to connect and communicate, this task was too large for just one standard. It had to be broken down into seven parts and layer them so each layer adds to the data before sending it down or subtracts data before sending it up. Yet each layer does not need changes from another layer in order for it to function. Each layer can operate independently or as part of a team. It is truly a remarkable setup.
There are four layers that WAN protocols operate. The session layer establishes, maintains, and terminates connections (sessions) between communicating applications. The transport layer does exactly what the name implies. It is the taxi for the data being transferred. The network layer establishes, maintains, and terminates connections with switching and data transmission technologies. The data link layer provides transportation of data from the physical layer. The physical layer deals with the switches and routers.
There are two layers that deal with switches and routers: the network and physical layers. It sounds redundant, but it is not. The physical layer only deals with the routers and switches. Only the physical elements of network while the network layer does more. The network layer establishes, maintains, and terminates connections while the physical layer only deals with the drivers of the physical mediums. The physical layers gets everything ready to be…...

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