Correct Answer - Option 4 : session
In ISO-OSI architecture, there are seven layers in this model. Starting from physical layer (layer 1), then data link layer, network layer, transport layer, session layer, presentation layer, application layer (layer - 7) respectively.
Session layer:
Session layer is the network dialog controller. It establishes, maintains and synchronizes the interaction among communicating system. It is responsible for dialog control, token management and synchronization in the network.
- Dialog control: Session layer allows two systems to enter into a dialog. It allows the communication between two processes to take place in either half-duplex or full – duplex.
- Synchronization: It allows a process to add checkpoints to a stream of data.
- Token management: It prevents two parties from attempting the same critical operation at the same time.
