The OSI Model consists of seven layers. These layers are the application layer, presentation layer, session layer, transport layer, network layer, data link layer, and physical layer. The Application Layer The application layer is responsible for interaction between the operating system and the network services and provides an interface to the system. It provides the user interface to a range of network wide distributed services including file transfer, printer access, and mail (Regan, 2004).Presentation Layer This layer makes sure that information sent by one application layer protocol from a remote system is readable by another application layer protocol in a remote system. It is a translator between different data formats, protocols, and systems.
Session Layer The Session Layer allows remote users to establish, manage, and terminate a connection. The session layer enables two users to organize and manage their data exchange and to implement dialog control between the source and destination network devices, including the type of dialog (simplex, half duplex, full duplex) and how long a computer transmits (Regan, 2004).Transport Layer The Transport Layer is the layer that connects the upper and lower layers together. The transport layer is also responsible for reliable, transparent transfer of data between two end points. Network Layer The Network Layer concerns itself with the addressing and routing necessary to move data from one network to another. Data Link Layer The Data Link Layer is responsible for sending data over the channel. It sends frames, defines the station address, and provides link management.