Q. Explain how presentation layer helps in processing and establishing data in End to End layers.

Ans:

The purpose of presentation layer is to represent information to communicating application entities in a way that preserves the meaning when resolving syntax differences. Syntax differences are resolved by encoding application data into a standard abstract notation which is valid throughout the network. So file format differences (for example IBM format or DEC format),data representation differences( for exampleEBCDIC or ASCII) or data structure differences are all resolved by using a standard notation. Data transformation and formatting may include encryption, data compression etc. There are two aspects which are associated with network wide handling of a range of data in a standard form, and second, transmission of data as a bit stream across the network.

This layer translates between various protocols and formats presenting functions data file formatting, encryption, encoding and decryption of data messages, data compression, dialogue procedures algorithms etc. This layer performs code and character set translation. And formatting information and determines display mechanism for message.