Layer 5 of OSI model known as OSI Session layer has a function to create and maintain connection between source applications and destination application. This layer handles the exchange of information to initiate the connection dialogs, keep it active and when needed to restart session that idle for a long time or disrupted. All the services provided are to serve presentation layer.
Examples of OSI session layer protocol are X.225, ISO 8327, NetBIOS (Network Basic Input Output System), PAP (Password Authentication Protocol) and many more. Services provided by layer 5 are commonly used in for make remote procedure calls that some application environments use it. For some case when connection loss, some protocols of session layer has ability to recover the connection or close the connection when not used and re-open the connection.