What Is The Session Layer In Osi Model?

What Is the Session Layer in OSI Model?

The session layer in the OSI model (open system interconnection) is the fifth layer which is responsible for the connection between the various computers. Between the computers session layer tracks the dialogs these are also called sessions. Between the local and remote applications session layer controls, establish, and ends the sessions.

The session layer manages the sessions by stimulating the opening and closing of the sessions between the users’ applications. This layer also controls the single or multiple connections and directly communicates with the transport layers and presentations. This service is only offered by the session layer and implemented in the applications environments using RPCs (remote procedure calls).

Mostly on web browsers sessions are implemented by using protocols such as the session control protocol, the AppleTalk protocol, and the zone information protocol.  These protocols are responsible for the management of the session restoration via recovery and checkpointing Both full-duplex and half-duplex are supported by session layers that create restart, termination, and checkpoint procedures. It also synchronizes information from different sources. For example, the session layer is implemented in TV shows when the audio and the video from the different sources are merged together. This helps in preventing overlapping and the silent broadcast site.

Functions:

• The session layer offers token management it prevents the two users try to access or attempting the same operation simultaneously.
• It controls the dialog through which it communicates with the full-duplex and the half-duplex modes of communication.
• Synchronization is achieved by adding checkpoints which are considered synchronization points to the streams of data.
• The session layer also offers recovery and checkpoints.
• Between the end-user application process, this layer provides the mechanism of the closing, opening, and management of the sessions.
• It synchronizes the information from different sources just like in TV shows.
• At the point from which the communication failure occurred session layer uses the checkpoints to enable communication and resumes from those points.
• From the transport layer, the session layer receives and catches data and sends it to the presentation layer after it.