Presentation Layer

Computer Networks:

Physical Layers

Data link Layer(DLL)

Network Layer

Transport Layer:

Session and Presentation Layer:

Application Layer:

Presentation layer:
The presentation layer is the six layer of the OSI reference model protocol stack, and second from the top. Which is different from the other layers in two respects.

first it has a much more Limited and specific function then the other layers. It is actually some what easy to describe.

Second it is used much less often then the other layers in many types of connection it is not required.
Presentation layers deals with the semantic and syntax text of the data.

Presentation layer function:

1) Translation:

Network can connected to very different types of computer together like PCs, UNIX system, servers on the same network.

Data is sent from sender to receiver but what if the sender device and the receiver device understand different formats of code here’s the presentation layer comes in action, it translate the data to other format in which the receiver can understand.

2) Encryption And decryption:

Whenever data is being transmitted between the sender and the receiver, that data must be secure because an Intruder can hack the data passing between the sender and the receiver.

The layer is liable for encoding (Encryption) and decoding(Decryption) information to keep away from information spillage and information change.

3) Compression And Decompression:

It become difficult to transmit the largest file over the network, Files can be decreased by compressing the file for easy transmission of data. Decreasing of the file size is known as compression. When the data compressed file is received at that receiver side the data is reconstructed back to the original size and this process is called Decompression.

Protocols of presentation layer:

Independent computing architecture (ICA):

It is a presentation layer Protocol in the OSI model which was formed by citrix system. It is used to transferring data from server to client.

Network data representation (NDR):

This protocol provides different kind of data representation such as image video audio number etc

Packet assembler/ Disassembler protocol (PAD):

It is a telecommunication equipment that split a stream of data into separate packet and format packets header for asynchronous communication. on X.25 network.

Lightweight presentation protocol (LPP ):

It is a protocol that offers ISO presentation services over TCP/IP base network