In OSI network architecture, dialogue control and token management are the…

Concept

Dialogue control, token management and synchronization are three closely-related session-management functions. Dialogue control governs whose turn it is to send, which matters in half-duplex exchange where only one side may transmit at a time; token management enforces this by passing a control token so that only the token-holder may send, preventing both ends from sending at once; synchronization inserts recovery checkpoints into the conversation.

In the seven-layer OSI model these three duties together define one specific layer: the Session layer (Layer 5), which establishes, manages and terminates the dialogue between two communicating applications.

Applying it here

The question lists exactly two of these defining functions — dialogue control and token management. Both are textbook duties of the Session layer, so the responsibility lies with the Session layer.

How the other layers differ

• Network layer — its job is logical addressing and routing of packets across networks (choosing the path), not coordinating whose turn it is to send between applications.

• Transport layer — its job is reliable process-to-process delivery: segmentation, end-to-end flow control and error recovery between endpoints, not passing dialogue control tokens.

• Data link layer — its job is framing bits and node-to-node delivery with error and flow control over a single physical link, not managing application conversations.

Cross-check: dialogue control, sessions and synchronization are the textbook hallmarks of Layer 5, which confirms the Session layer.