7 Layers of the Osi Model

7 Layers of the OSI Model

APPLICATION-controls how the operating system and its application interact with the network. The application we use such as MS Access benefit from the work that goes on at this layer and it controls how the OS and application interact.

PRESENTATION- takes the data from the lower layers and transfers it to be presented to the system. The function that takes place can include data compression, decompression, data encryption, and decryption.

SESSION- defines the connection from a user computer to a network server or from a peer computer on a network to another peer computer. The function includes negotiation between client, host, peer to peer, flow control, transaction processing, transfer of user information, and authentication to the network.

TRANSPORT- manages the flow of information from on network node to another. It ensures that the packets are decoded in the proper sequence and that all packets are received. It also identifies each computer or node on a network uniquely.

NETWORK- defines how data packets get from one point to another one a network and what goes into each packet. Defines different packet protocols, such as IP and IPX. These packets protocols include source and destination routing information.

DATA LINK- defines standards that assign meaning to the bits carried by the physical layer. It establishes a reliable protocol through the physical layer so the network layer can transmits its data.

PHYSICAL- defines the properties of the physical medium used to make a network connection. The physical connection can be either point to point or multipoint. The specification for the physical layer also defines the cable used, the voltages carried on the cable, the timing of the electrical signals, the distance can be run.