The main function of the OSI model's session layer is to control "sessions", which are logical connections between network devices. A session consists of a dialog, or data communications conversation, between two presentation entities. Dialogs can be
• simplex (one-way)
• half-duplex (alternate)
• full-duplex (bi-directional)
Simplex conversations are rare on networks. Half-duplex conversations require a good deal of session layer control, because the start and end of each transmission need to be monitored.
Most networks are of course capable of full-duplex transmission, but in fact many conversations are in practice half-duplex.
• half-duplex (alternate)
• full-duplex (bi-directional)
Simplex conversations are rare on networks. Half-duplex conversations require a good deal of session layer control, because the start and end of each transmission need to be monitored.
Most networks are of course capable of full-duplex transmission, but in fact many conversations are in practice half-duplex.
Devices:-
Some examples of session layer protocols and interfaces are:
• Network File System (NFS)
• Concurrent database access
• X-Windows System
• Concurrent database access
• X-Windows System
• Remote Procedure Call (RPC)
• SQL
• NetBIOS Names
• AppleTalk Session Protocol (ASP)
• Digital Network Architecture
• AppleTalk Session Protocol (ASP)
• Digital Network Architecture
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