Describe the functions of the Session layer in the OSI model

Communication between applications is controlled by the session layer. Session management is concerned with establishing, managing, and terminating communication connections. Service requests and responses are transmitted between applications on different devices during communication sessions. Specifications that operate at the session layer include Session Control Protocol (SCP), H.245 and H.225. One example of a session layer protocol is Network Basic Input/Output System (NetBIOS).

Session Initiation Protocol (SIP) is another example of a session layer protocol that is used to establish, maintain, and destroy voice or video connections. It is important to note, however, that not every network application maps directly to each of the seven layers of the OSI model.

One of the challenges about the session layer is that it might not be possible to identify the protocol running within it in any particular scenario. In order to set up a session, the following procedures must be followed: Checking user credentials (such as username and password). Each communication flow in a session is assigned a number to make it easier to locate it.locate it. Negotiating services which are required during the session. Determining which device begins transmitting data. In order to maintain a session, a variety of procedures are necessary, such as: Transferring the data. Establishing a disconnected session. Acknowledging receipt of the data. A session may be disconnected if the devices participating in the session agree to do so. Furthermore, a session may be terminated when one party disconnects (either intentionally or due to an error condition). If one of the parties disconnects from the session, the other party may detect a loss of communication with that party and dissolve the session.

Written by pramod