Session Layer

Introduction

• The session layer is the 5th layer of the OSI model.
• This layer lies in between the Transport layer and the Presentation layer.

Features

• The session layer controls and coordinates the dialogues or data-exchange process between senders’ and receivers’ computers during communication in an orderly manner.
• This layer is mostly implemented in application environments that use remote procedure calls(RPC).

Functions

• Session Creation:
  • The Session layer decides when to turn communication on and off between two computers.
  • It establishes, maintains, and terminates the logical connections or sessions between two systems(the local and remote applications located on the client and server)to enter into a dialog or communication, or sharing.
• Authentication & Authorization:
  • This layer handles all the important log-on or password verification & validation, i.e. Authentication & Authorization. If found true, the session is created for authenticated users.
• Transmission Mode:
  • It determines one-way or two-way communications i.e. the half-duplex or duplex mode and manages the dialogue between both parties.
• Checkpoints Creation/Session Restoration:
  • It also marks significant parts of the transmitted data with checkpoints to allow for fast recovery in the event of a connection failure.
• Synchronization:
  • The Session layer helps in coordinating the flow control of the audio and video data during transmission/webinar so that both are appearing in synchronize way at the receiver’s end.