Which layer is responsible for dialog control in the OSI model?

When two computers or applications communicate, the session layer helps organize that conversation. Dialog control ensures that both systems know when to talk and when to listen. It helps in two types of communication:

• Half-duplex: Only one device sends data at a time.


• Full-duplex: Both devices can send and receive at the same time.

The Session Layer sets up, manages, and ends these dialogs. It also keeps the session in sync using checkpoints. If the connection breaks, it can resume from the last checkpoint instead of starting over.

Key responsibilities of the Session Layer:

• Manages dialog control (who speaks and who listens).


• Handles session setup and termination.


• Maintains session synchronization using checkpoints.


• Supports full-duplex and half-duplex communication.

Conclusion: The correct answer is Session Layer. This layer plays a critical role in communication by managing the flow and order of messages. Understanding this concept is helpful for networking students and interview preparation related to OSI model layers.