16.6 SESSION LAYER

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16.6 SESSION LAYER

The session layer specifies the mechanism for controlling the dialogue in the end systems. Session layer functionality is as follows:

• Dialogue discipline: whether the communication should be full duplex or half duplex.

• Grouping: to group data into logical units.

• Recovery: a mechanism for recovery in case of intermittent failures of the links.

The functionality of session layer is to provide recovery mechanism in case of intermittent failure of links and to negotiate whether the communication should be full-duplex or half-duplex.

Because it does not have much work to do, in many networks, there is no session layer.

Note 

In many practical networks, the functionality of the session layer is taken by other layers, and the session layer is just a null layer.

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