The session layer (control of logical connections) provides process communication between two systems. Here you will find, among other things, the protocol RPC "Remote Procedure Call".
To resolve session breakdowns and similar issues, the session layer provides services for organized and synchronized data sharing. For this purpose, recovery points, so-called check points are introduced, at which the session can be synchronized again after a failure of a transport connection, without the transfer must start all over again.
Protocols and Standards: ISO 8326 / X.215 (Session Service), ISO 8327 / X.225 Connection-Oriented Session Protocol, ISO 9548 Connectionless Session Protocol