What is Presentation Layer
Definition: Presentation layer is 6th layer in the OSI model, and its main objective is to present all messages to upper layer as a standardized format. It is also known as the “Translation layer“.
This layer takes care of syntax and semantics of messages exchanged in between two communication systems. Presentation layer has responsible that receiver can understand all data, and it will be to implement all data languages can be dissimilar of two communication system.
Presentation layer is capable to handle abstract data structures, and further it helps to defined and exchange of higher-level data structures.
Functions of Presentation Layer
Presentation layer performs various functions in the OSI model; below explain each one –
- Presentation layer helps to translate from American standard code for information interchange (ASCII) to the extended binary code decimal interchange code (EBCDIC).
- It deals with user interface as well as supporting for several services such as email and file transfer.
- It provides encoding mechanism for translating all messages from user dependent format with common format and vice – versa.
- It’s main goal for data encryption and decryption of entire data before they are getting transmission over all common platforms.
- It provides data compression mechanism for source point to decrease the all bits which are transmitted. Due to this data compression system, user are able to transmit enlarge multimedia file at fastest file transfer rate.
- Due to use of Data Encryption and Decryption algorithm, presentation layer provides more network protection and confidentiality while transmission data over the entire network.
- This layer offers best flexibility for data translation for making connections with various kinds of servers, computers, and mainframes over the similar network.
- Presentation layer has responsible to fix all translations in between all network systems.
Protocols of Presentation Layer
Presentation layer is used various protocols; below list is available –
- Multipurpose Internet Mail Extensions
- File Transfer Protocol
- Network News Transfer Protocol
- Apple Filing Protocol (AFP)
- Independent Computing Architecture (ICA), the Citrix system core protocol
- Lightweight Presentation Protocol (LPP)
- NetWare Core Protocol (NCP)
- Network Data Representation (NDR)
- Telnet (a remote terminal access protocol)
- Tox Protocol
- eXternal Data Representation (XDR)
- 25 Packet Assembler/Disassembler Protocol (PAD)
Example of Presentation Layer Protocols
Here, we will discuss all examples of presentation layer protocols; below explain each one –
Multipurpose Internet Mail Extensions (MIME): MIME protocol was introduced by Bell Communications in 1991, and it is an internet standard that provides scalable capable of email for attaching of images, sounds and text in a message.
File Transfer Protocol (FTP): FTP is a internet protocol, and its main goal is to transmit all files in between one host to other hosts over the internet on TCP/IP connections.
Network News Transfer Protocol (NNTP): This protocol is used to make connection with Usenet server and transmit all newsgroup articles in between system over internet.
Apple Filing Protocol (AFP): AFP protocol is designed by Apple company for sharing all files over the entire network.
Lightweight Presentation Protocol (LPP): This protocol is used to offer ISO presentation services on top of TCP/IP based protocol stacks.
NetWare Core Protocol (NCP): NCP is a Novell client server model protocol that is designed especially for Local Area Network(LAN). It is capable to perform several functions like as file/print-sharing, clock synchronization, remote processing and messaging.
Network Data Representation (NDR): NDR is an data encoding standard, and it is implement in the Distributed Computing Environment (DCE).
Telnet (Telecommunication Network): Telnet protocol was introduced in 1969, and it offers the command line interface for making communication along with remote device or server.
Tox: The Tox protocol is sometimes regarded as part of both the presentation and application layer, and it is used for sending peer-to-peer instant-messaging as well as video calling.
eXternal Data Representation (XDR): This protocol provides the description and encoding of entire data, and it’s main goal is to transfer data in between dissimilar computer architecture.
25 Packet Assembler/Disassembler Protocol (PAD): Main objective of this protocol is to obtain all data from group of terminal and allots the data into X. 25 packets.
Presentation Layer Services
Presentation layer provides several services like as –
- Data conversion
- Character code translation
- Encryption and Decryption
Design Issues with Presentation Layer
- It helps to handle and maintain Syntax and Semantics of the message transmitted.
- Encoding data can be done as standard agreed like as String, double, date, and more.
- Standard Encoding can be done on wire.