Presentation layer gets its name from its purpose: It presents data to the
Application layer. It’s essentially a translator and provides coding and conversion functions. A successful data transfer technique is to adapt the data
into a standard format before transmission. Computers are configured to
receive this generically formatted data and then convert the data back into its
native format for actual reading (for example, EBCDIC to ASCII). By providing translation services, the Presentation layer ensures that data transferred from the Application layer of one system can be read by the
Application layer of another host.
The OSI has protocol standards that define how standard data should be
formatted. Tasks like data compression, decompression, encryption, and
decryption are associated with this layer. Some Presentation layer standards
are involved in multimedia operations. The following serve to direct graphic
and visual image presentation:
PICT This is picture format used by Macintosh or PowerPC programs
for transferring QuickDraw graphics.
TIFF The Tagged Image File Format is a standard graphics format for
high-resolution, bitmapped images.
It ensures that information sent by the application layer of one system will be readable by the application layer of another system. It provides a common format for transmitting data across various systems, so that data can be understood, regardless of the types of machines involved.
The presentation layer concerns itself not only with the format and representation of actual user data, but also with data structure used by programs. Therefore, the presentation layer negotiates data transfer syntax for the application layer.
Application layer. It’s essentially a translator and provides coding and conversion functions. A successful data transfer technique is to adapt the data
into a standard format before transmission. Computers are configured to
receive this generically formatted data and then convert the data back into its
native format for actual reading (for example, EBCDIC to ASCII). By providing translation services, the Presentation layer ensures that data transferred from the Application layer of one system can be read by the
Application layer of another host.
The OSI has protocol standards that define how standard data should be
formatted. Tasks like data compression, decompression, encryption, and
decryption are associated with this layer. Some Presentation layer standards
are involved in multimedia operations. The following serve to direct graphic
and visual image presentation:
PICT This is picture format used by Macintosh or PowerPC programs
for transferring QuickDraw graphics.
TIFF The Tagged Image File Format is a standard graphics format for
high-resolution, bitmapped images.
It ensures that information sent by the application layer of one system will be readable by the application layer of another system. It provides a common format for transmitting data across various systems, so that data can be understood, regardless of the types of machines involved.
The presentation layer concerns itself not only with the format and representation of actual user data, but also with data structure used by programs. Therefore, the presentation layer negotiates data transfer syntax for the application layer.
Devices:-
• Encryption
• EBCDIC and ASCII
• GIF & JPEG
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