The fifth layer of the OSI Model- the Session layer

The session layer is the fifth layer of the OSI Model. This is come after the transport layer. This is the Session layer which decides when to turn communication off and on between two computers. It provides the mechanism that control the data exchange process and co-ordinate the interaction between them.

The Session layer defines how to start, control and end the conversation between the two system .the services provided by the first three layer-physical layer, data link layer and the network layer are not sufficient for the some process. The session layer is the Network Dialog Controller. It establishes, maintain and synchronize the interaction between the communicating systems.

Responsibilities of the Session layer-

1. The Session layer is responsible for the setting up, managing and then turning down the session between two systems.
2. It co-ordinates communication between systems and servers to organize their communication.
3. The Session layer allows two systems to enter in to a dialog. it allow the communication between two process either in half duplex –one way at a time or full duplex-two way at a time.
4. The Session layer is also allowed to add the checkpoints into a stream of the data.

The protocol uses in the Session layer are –SQL (Structure Query Language),

RPC (Remote Procedure Call), Apple talk Session Protocol (ASP) etc.

Related posts:

1. The First Layer of OSI Model-Physical layer
2. Physical Layer
3. The seventh layer of the OSI Model- the Application Layer
4. The Sixth layer of the OSI Model- The Presentation layer
5. The fourth layer of the OSI Model-Transport layer

This entry was posted on Friday, November 13th, 2009 at 8:05 pm and is filed under General CCNA. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.