What is the main role of a session layer in OSI model and what are the protocols foes it uses?

Session layer is responsible for synchronization and dialog control.

Some session layer protocols are:

SMPP: Short Message Peer to Peer

SCP: Session Control Protocol

PPTP: Point to Point Tunelling Protocol

PAP: Password Authentication Protocol

The session layer provides the mechanism for opening, closing and managing a session between end-user application processes, Communication sessions consist of requests and responses that occur between applications. Session-layer services are commonly used in application environments that make use of remote procedure calls (RPCs).

session layer is primarily responsible for setting up and managing communicative sessions, thereby enabling the sending and receiving of data for an undetermined length of time—similar to a telephone call. Additionally, the session layer is responsible for terminating sessions between software processes.

5. Session layer  is layer 5   the session if a connection is not used  for a long period  the session layer protocols  may close  it and  re-open it.

Session layer establishes, controls and ends the sessions between local and remote applications.(tracks the dialogs between multiple computers)

According there name it going to build session between source & destination like when we are opening any site on browser then it's responcebale to create a back to back connectivity with destination point for us. And it is 5th layer of OSI model.

The main role of seesion layer is managing and setting up the data,

Some session layer protocols are:

SMPP: Short Message Peer to Peer

SCP: Session Control Protoco