presentation layer

• Engineering Mathematics
• Discrete Mathematics
• Operating System
• Computer Networks
• Digital Logic and Design
• C Programming
• Data Structures
• Theory of Computation
• Compiler Design
• Computer Org and Architecture

Presentation Layer in OSI model

Prerequisite : OSI Model

Introduction : Presentation Layer is the 6th layer in the Open System Interconnection (OSI) model. This layer is also known as Translation layer, as this layer serves as a data translator for the network. The data which this layer receives from the Application Layer is extracted and manipulated here as per the required format to transmit over the network. The main responsibility of this layer is to provide or define the data format and encryption. The presentation layer is also called as Syntax layer since it is responsible for maintaining the proper syntax of the data which it either receives or transmits to other layer(s).

Functions of Presentation Layer :

The presentation layer, being the 6th layer in the OSI model, performs several types of functions, which are described below-

• Presentation layer format and encrypts data to be sent across the network.
• This layer takes care that the data is sent in such a way that the receiver will understand the information (data) and will be able to use the data efficiently and effectively.
• This layer manages the abstract data structures and allows high-level data structures (example- banking records), which are to be defined or exchanged.
• This layer carries out the encryption at the transmitter and decryption at the receiver.
• This layer carries out data compression to reduce the bandwidth of the data to be transmitted (the primary goal of data compression is to reduce the number of bits which is to be transmitted).
• This layer is responsible for interoperability (ability of computers to exchange and make use of information) between encoding methods as different computers use different encoding methods.
• This layer basically deals with the presentation part of the data.
• Presentation layer, carries out the data compression (number of bits reduction while transmission), which in return improves the data throughput.
• This layer also deals with the issues of string representation.
• The presentation layer is also responsible for integrating all the formats into a standardized format for efficient and effective communication.
• This layer encodes the message from the user-dependent format to the common format and vice-versa for communication between dissimilar systems.
• This layer deals with the syntax and semantics of the messages.
• This layer also ensures that the messages which are to be presented to the upper as well as the lower layer should be standardized as well as in an accurate format too.
• Presentation layer is also responsible for translation, formatting, and delivery of information for processing or display.
• This layer also performs serialization (process of translating a data structure or an object into a format that can be stored or transmitted easily).

Features of Presentation Layer in the OSI model: Presentation layer, being the 6th layer in the OSI model, plays a vital role while communication is taking place between two devices in a network.

List of features which are provided by the presentation layer are:

• Presentation layer could apply certain sophisticated compression techniques, so fewer bytes of data are required to represent the information when it is sent over the network.
• If two or more devices are communicating over an encrypted connection, then this presentation layer is responsible for adding encryption on the sender’s end as well as the decoding the encryption on the receiver’s end so that it can represent the application layer with unencrypted, readable data.
• This layer formats and encrypts data to be sent over a network, providing freedom from compatibility problems.
• This presentation layer also negotiates the Transfer Syntax.
• This presentation layer is also responsible for compressing data it receives from the application layer before delivering it to the session layer (which is the 5th layer in the OSI model) and thus improves the speed as well as the efficiency of communication by minimizing the amount of the data to be transferred.

Working of Presentation Layer in the OSI model : Presentation layer in the OSI model, as a translator, converts the data sent by the application layer of the transmitting node into an acceptable and compatible data format based on the applicable network protocol and architecture.  Upon arrival at the receiving computer, the presentation layer translates data into an acceptable format usable by the application layer. Basically, in other words, this layer takes care of any issues occurring when transmitted data must be viewed in a format different from the original format. Being the functional part of the OSI mode, the presentation layer performs a multitude (large number of) data conversion algorithms and character translation functions. Mainly, this layer is responsible for managing two network characteristics: protocol (set of rules) and architecture.

Presentation Layer Protocols : Presentation layer being the 6th layer, but the most important layer in the OSI model performs several types of functionalities, which makes sure that data which is being transferred or received should be accurate or clear to all the devices which are there in a closed network. Presentation Layer, for performing translations or other specified functions, needs to use certain protocols which are defined below –

• Apple Filing Protocol (AFP): Apple Filing Protocol is the proprietary network protocol (communications protocol) that offers services to macOS or the classic macOS. This is basically the network file control protocol specifically designed for Mac-based platforms.
• Lightweight Presentation Protocol (LPP): Lightweight Presentation Protocol is that protocol which is used to provide ISO presentation services on the top of TCP/IP based protocol stacks.
• NetWare Core Protocol (NCP): NetWare Core Protocol is the network protocol which is used to access file, print, directory, clock synchronization, messaging, remote command execution and other network service functions.
• Network Data Representation (NDR): Network Data Representation is basically the implementation of the presentation layer in the OSI model, which provides or defines various primitive data types, constructed data types and also several types of data representations.
• External Data Representation (XDR): External Data Representation (XDR) is the standard for the description and encoding of data. It is useful for transferring data between computer architectures and has been used to communicate data between very diverse machines. Converting from local representation to XDR is called encoding, whereas converting XDR into local representation is called decoding.
• Secure Socket Layer (SSL): The Secure Socket Layer protocol provides security to the data that is being transferred between the web browser and the server. SSL encrypts the link between a web server and a browser, which ensures that all data passed between them remains private and free from attacks.

Similar Reads

• Computer Network Tutorial A computer network is a collection of computers or devices connected to share resources. Any device which can share or receive the data is called a Node. Through which the information or data propagate is known as channels, It can be guided or unguided. In this Computer network tutorial, you’ll lear 8 min read

Basics of Computer Network

• Basics of Computer Networking Computer networking is very important in modern technology, enabling the interconnected systems that power the Internet, business communications, and everyday digital interactions. Understanding the fundamentals of computer networking is essential for anyone involved in technology, from enthusiasts 14 min read
• Introduction to basic Networking Terminology For a specific purpose if things are connected together, are referred to as a NETWORK. A network can be of many types, like a telephone network, television network, computer network, or even a people network. Similarly, a COMPUTER NETWORK is also a kind of setup, where it connects two or more device 4 min read
• Goals of Networks Computer Network means an interconnection of autonomous (standalone) computers for information exchange. The connecting media could be a copper wire, optical fiber, microwave, or satellite. Networking Elements - The computer network includes the following networking elements: At least two computers 4 min read
• Basic Characteristics of Computer Networks Computer networks allow multiple devices to connect and share resources like files, printers, and internet access. Key characteristics include the network's size (like local or wide area), the way data is transferred (wired or wireless), and the network's layout (such as star or mesh). These feature 5 min read
• Challenges of Computer Network In the age of Internet where everyone loves to work with their computers and smart phones it is impossible to think any work without networking. With advancement of technology use of computer networking is increasing rapidly. In general if we will see, we can feel also how important networking is th 4 min read
• Physical Components of Computer Network The physical components of a computer network include hardware devices and media that enable connectivity and data exchange between devices. The server, client, peer, transmission media, and connecting devices make up the hardware components. A computer network is made up of several computers connec 6 min read

Network Hardware and Software

• Types of Computer Networks A computer network is a cluster of computers over a shared communication path that works to share resources from one computer to another, provided by or located on the network nodes. In this article, we will discuss computer networks and their types. What is a Computer Network?A computer network is 11 min read
• LAN Full Form A Local area network (LAN) is a network that is used to link devices in a single office, building, or campus of up to a short distance. LAN is restricted in size. In LAN networks internet speed is from 10 Mbps to 100 Mbps (But now much higher speeds can be achieved). The most common topologies used 10 min read
• How to Set Up a LAN Network? LAN (Local Area Network) is a data communication network that locally connects network devices such as workstations, servers, routers, etc. to share the resources within a small area such as a building or campus. Physical or wireless connections are set up between workstations to share the resources 4 min read
• MAN Full Form in Computer Networking A Metropolitan Area Network (MAN) is a type of computer network that spans over a metropolitan area, typically a city. It provides high-speed data communication services such as video, audio, and data transfer between multiple LANs (Local Area Networks) and WANs (Wide Area Networks). The main purpos 9 min read
• MAN Full Form MAN stands for Metropolitan Area Network and it is made by connecting multiple LANs. MAN covers a geographical area which is known as the metropolitan area. It serves as a connection that is larger than LAN(Local Area Network) but smaller than WAN(Wide Area Network). It generally covers the area of 5 min read
• WAN Full Form A WAN (Wide Area Network) is to connect multiple smaller Local Area Networks (LANs). It is a computer network designed. WANs can help in communication, the sharing of information, and much more between systems or devices from around the world through a WAN provider. What is a WAN?WAN stands for Wide 5 min read
• Introduction of Internetworking Internetworking is combined of 2 words, inter and networking which implies an association between totally different nodes or segments. This connection area unit is established through intercessor devices akin to routers or gateway. The first term for associate degree internetwork was catenet. This i 8 min read
• Difference between Internet, Intranet and Extranet Networks are crucial in today’s globalized world because they allow the acquisition, exchange, and organization of knowledge. Of all the first order networks the Internet, Intranet, and Extranet are commonly utilized for various applications. Every network type meets specific roles that are required 5 min read
• Protocol Hierarchies in Computer Network A Protocol Hierarchy is a fixed set of rules and conventions that govern the communication between two or more computers. The hierarchical structure allows for modular design, interoperability, and ease of implementation in computer networks. What is Protocol?A protocol is simply defined as a set of 3 min read
• Network Devices (Hub, Repeater, Bridge, Switch, Router, Gateways and Brouter) Network devices are physical devices that allow hardware on a computer network to communicate and interact with each other. Network devices like hubs, repeaters, bridges, switches, routers, gateways, and brouters help manage and direct data flow in a network. They ensure efficient communication betw 10 min read
• Introduction of a Router Network devices are physical devices that allow hardware on a computer network to communicate and interact with one another. For example Repeater, Hub, Bridge, Switch, Routers, Gateway, Router, and NIC, etc. What is a Router?A Router is a networking device that forwards data packets between computer 12 min read
• Introduction of Gateways A gateway is a network connectivity device that connects two different configuration networks. Gateways are also known as protocol converters, because they play an important role in converting protocols supported by traffic on different networks. As a result, it allows smooth communication between t 5 min read
• What is a Network Switch and How Does it Work? The Switch is a network device that is used to segment the networks into different subnetworks called subnets or LAN segments. It is responsible for filtering and forwarding the packets between LAN segments based on MAC address.  Switches have many ports, and when data arrives at any port, the desti 9 min read

Network Topology

• Types of Network Topology Network topology refers to the arrangement of different elements like nodes, links, or devices in a computer network. Common types of network topology include bus, star, ring, mesh, and tree topologies, each with its advantages and disadvantages. In this article, we will discuss different types of n 12 min read
• Difference between Physical and Logical Topology A Physical and Logical topologies are important concepts that govern the formation and operation of networks. In this article we will see differences between both topologies, and troubleshooting network infrastructure. What is Physical Topology?Physical topology indicates the arrangement of differen 5 min read
• What is OSI Model? - Layers of OSI Model The OSI (Open Systems Interconnection) Model is a set of rules that explains how different computer systems communicate over a network. OSI Model was developed by the International Organization for Standardization (ISO). The OSI Model consists of 7 layers and each layer has specific functions and re 14 min read
• Physical Layer in OSI Model The physical Layer is the bottom-most layer in the Open System Interconnection (OSI) Model which is a physical and electrical representation of the system. It consists of various network components such as power plugs, connectors, receivers, cable types, etc. The physical layer sends data bits from 5 min read
• Data Link Layer The data link layer is the second layer from the bottom in the OSI (Open System Interconnection) network architecture model. It is responsible for the node-to-node delivery of data. Its major role is to ensure error-free transmission of information. DLL is also responsible for encoding, decoding, an 5 min read
• Session Layer in OSI model Prerequisite : OSI Layer Introduction :The Session Layer is the 5th layer in the Open System Interconnection (OSI) model. This layer allows users on different machines to establish active communications sessions between them. It is responsible for establishing, maintaining, synchronizing, terminatin 5 min read
• Presentation Layer in OSI model Prerequisite : OSI Model Introduction : Presentation Layer is the 6th layer in the Open System Interconnection (OSI) model. This layer is also known as Translation layer, as this layer serves as a data translator for the network. The data which this layer receives from the Application Layer is extra 6 min read
• Application Layer in OSI Model The Application Layer of OSI (Open System Interconnection) model, is the top layer in this model and takes care of network communication. The application layer provides the functionality to send and receive data from users. It acts as the interface between the user and the application. The applicati 9 min read
• Protocol and Standard in Computer Networks Protocols and standards are important in computer networks. They are like the rules and guidelines that allow different devices and systems to communicate and work together smoothly. Protocols define how data is sent, received, and processed, while standards ensure that various technologies are comp 9 min read
• Examples of Data Link Layer Protocols Data Link Layer protocols are generally responsible to simply ensure and confirm that the bits and bytes that are received are identical to the bits and bytes being transferred. It is basically a set of specifications that are used for implementation of data link layer just above the physical layer 4 min read

TCP/IP Model

• TCP/IP Model The TCP/IP model is a fundamental framework for computer networking. It stands for Transmission Control Protocol/Internet Protocol, which are the core protocols of the Internet. This model defines how data is transmitted over networks, ensuring reliable communication between devices. It consists of 14 min read
• TCP/IP Ports and Its Applications A port is the logical address of any protocol; alternatively, we might think of a port as a special door for each protocol, through which all packets are routed. Another way to put it is that every protocol has a mailbox, or box, where every protocol packet is dropped. Subsequently, the recipient wi 6 min read
• What is TCP (Transmission Control Protocol)? TCP (Transmission Control Protocol) is one of the main protocols of the TCP/IP suite. It lies between the Application and Network Layers which are used in providing reliable delivery services. Transmission Control Protocol (TCP) ensures reliable and efficient data transmission over the internet. TCP 6 min read
• TCP 3-Way Handshake Process The TCP 3-Way Handshake is a fundamental process that establishes a reliable connection between two devices over a TCP/IP network. It involves three steps: SYN (Synchronize), SYN-ACK (Synchronize-Acknowledge), and ACK (Acknowledge). During the handshake, the client and server exchange initial sequen 7 min read
• Services and Segment structure in TCP The Transmission Control Protocol is the most common transport layer protocol. It works together with IP and provides a reliable transport service between processes using the network layer service provided by the IP protocol. The various services provided by the TCP to the application layer are as f 5 min read
• TCP Connection Establishment Prerequisite – TCP 3-Way Handshake Process TCP is a connection-oriented protocol and every connection-oriented protocol needs to establish a connection in order to reserve resources at both the communicating ends. Connection Establishment - TCP connection establishment involves a three-way handshake 3 min read
• TCP Connection Termination In TCP 3-way Handshake Process we studied that how connections are established between client and server in Transmission Control Protocol (TCP) using SYN bit segments. In this article, we will study how TCP close connection between Client and Server. Here we will also need to send bit segments to a 5 min read
• TCP Timers TCP uses several timers to ensure that excessive delays are not encountered during communications. Several of these timers are elegant, handling problems that are not immediately obvious at first analysis. Each of the timers used by TCP is examined in the following sections, which reveal its role in 4 min read
• Fast Recovery Technique For Loss Recovery in TCP When the RTO timer expires but an ACK is not received, the sender confirms that the packet is lost due to congestion at intermediary devices. Now sender has to tackle this congestion state carefully. Fast Recovery is the packet loss recovery technique. Recovery means becoming inactive and not transm 4 min read
• Difference Between OSI Model and TCP/IP Model Data communication is a process or act in which we can send or receive data. Understanding the fundamental structures of networking is crucial for anyone working with computer systems and communication. For data communication two models are available, the OSI (Open Systems Interconnection) Model, an 5 min read

Medium Access Control

• MAC Full Form MAC refers to Media Access Control, which is an important issue in network technology. In simple words, MAC is a series of rules through which devices can transfer data among them in a network. When a device is connected to a network, it obtains a unique MAC address. It identifies a device connected 5 min read
• Channel Allocation Problem in Computer Network Channel allocation is a process in which a single channel is divided and allotted to multiple users in order to carry user specific tasks. There are user's quantity may vary every time the process takes place. If there are N number of users and channel is divided into N equal-sized sub channels, Eac 3 min read
• Multiple Access Protocols in Computer Network Multiple Access Protocols are methods used in computer networks to control how data is transmitted when multiple devices are trying to communicate over the same network. These protocols ensure that data packets are sent and received efficiently, without collisions or interference. They help manage t 9 min read
• Carrier Sense Multiple Access (CSMA) Carrier Sense Multiple Access (CSMA) is a method used in computer networks to manage how devices share a communication channel to transfer the data between two devices. In this protocol, each device first sense the channel before sending the data. If the channel is busy, the device waits until it is 9 min read
• Collision Detection in CSMA/CD CSMA/CD (Carrier Sense Multiple Access/ Collision Detection) is a media access control method that was widely used in Early Ethernet technology/LANs when there used to be shared Bus Topology and each node ( Computers) was connected by Coaxial Cables. Nowadays Ethernet is Full Duplex and Topology is 7 min read
• Controlled Access Protocols in Computer Network Controlled Access Protocols (CAPs) in computer networks control how data packets are sent over a common communication medium. These protocols ensure that data is transmitted efficiently, without collisions, and with little interference from other data transmissions. In this article, we will discuss 6 min read

SLIDING WINDOW PROTOCOLS

• Stop and Wait ARQ Stop and Wait ARQ is a Sliding Window Protocol method used for the reliable delivery of data frames. The stop-and-wait ARQ is used for noisy channels or links to handle flow and error control between sender and receiver. The Stop and Wait ARQ protocol sends a data frame and then waits for an acknowl 9 min read
• Sliding Window Protocol | Set 3 (Selective Repeat) Prerequisite : Sliding Window Protocol - Set 1 (Sender Side), Set 2 (Receiver Side) Why Selective Repeat Protocol? The go-back-n protocol works well if errors are less, but if the line is poor it wastes a lot of bandwidth on retransmitted frames. An alternative strategy, the selective repeat protoco 3 min read
• Piggybacking in Computer Networks Pre-Requisite: Transmission Mode in Computer Networks Piggybacking is the technique of delaying outgoing acknowledgment and attaching it to the next data packet.  When a data frame arrives, the receiver waits and does not send the control frame (acknowledgment) back immediately. The receiver waits u 5 min read

IP Addressing

• What is IPv4? IP stands for Internet Protocol version v4 stands for Version Four (IPv4), is the most widely used system for identifying devices on a network. It uses a set of four numbers, separated by periods (like 192.168.0.1), to give each device a unique address. This address helps data find its way from one 5 min read
• What is IPv6? The most common version of the Internet Protocol currently is IPv6. The well-known IPv6 protocol is being used and deployed more often, especially in mobile phone markets. IP address determines who and where you are in the network of billions of digital devices that are connected to the Internet. It 5 min read
• Introduction of Classful IP Addressing An IP address is an address that has information about how to reach a specific host, especially outside the LAN. An IP address is a 32-bit unique address having an address space of 232. Classful IP addressing is a way of organizing and managing IP addresses, which are used to identify devices on a n 10 min read
• Classless Addressing in IP Addressing The Network address identifies a network on the internet. Using this, we can find a range of addresses in the network and total possible number of hosts in the network. Mask is a 32-bit binary number that gives the network address in the address block when AND operation is bitwise applied on the mas 7 min read
• Classful vs Classless Addressing Classful and Classless addressing are methods used in networking to manage IP addresses. Classful addressing divides IP addresses into fixed classes (A, B, C, D, E), each with predefined ranges. In contrast, classless addressing, also known as CIDR (Classless Inter-Domain Routing), offers more flexi 7 min read
• Classless Inter Domain Routing (CIDR) Classless Inter-Domain Routing (CIDR) is a method of IP address allocation and IP routing that allows for more efficient use of IP addresses. CIDR is based on the idea that IP addresses can be allocated and routed based on their network prefix rather than their class, which was the traditional way o 6 min read
• Supernetting in Network Layer Supernetting is the opposite of Subnetting. In subnetting, a single big network is divided into multiple smaller subnetworks. In Supernetting, multiple networks are combined into a bigger network termed a Supernetwork or Supernet. In this article, we'll explore the purpose and advantages of supernet 4 min read
• Introduction To Subnetting Subnetting is the process of dividing a large network into smaller networks called as "subnets." Subnets provides each group of devices have thier own space to communicate, that ultimately helps network to work easily. This also boosts security and makes it easier to manage the network, as each subn 8 min read
• Difference between Subnetting and Supernetting Subnetting is the procedure to divide the network into sub-networks or small networks, these smaller networks are known as subnets. The subnet is also defined as an internal address made up of a combination of a small network and host segments. In a subnet, a few bits from the host portion are used 4 min read
• Types of Routing Routing is the process of determining paths through a network for sending data packets. It ensures that data moves effectively from source to destination, making the best use of network resources and ensuring consistent communication. Routing performed by layer 3 (or network layer) devices to delive 6 min read
• Difference between Static and Dynamic Routing Routing is a vital communication mechanism that governs how data packets travel from source to destination. Effective routing ensures that data is transferred across networks in an efficient, reliable, and timely manner. There are two main forms of routing: static and dynamic. In this article, we wi 4 min read
• Unicast Routing - Link State Routing Prerequisite: Distance Vector Routing, Dijkstra algorithm Unicast means the transmission from a single sender to a single receiver. It is a point-to-point communication between the sender and receiver. There are various unicast protocols such as TCP, HTTP, etc.   TCP is the most commonly used unicas 7 min read
• Distance Vector Routing (DVR) Protocol Distance Vector Routing (DVR) Protocol is a method used by routers to find the best path for data to travel across a network. Each router keeps a table that shows the shortest distance to every other router, based on the number of hops (or steps) needed to reach them. Routers share this information 5 min read
• Fixed and Flooding Routing algorithms In most situations, packets require multiple hops to make a journey towards the destination. Routing is one of the most complex and crucial aspects of packet-switched network design. Desirable Properties of Routing Algorithms:- Correctness and SimplicityRobustness: Ability of the network to deliver 5 min read
• Introduction of Firewall in Computer Network In the world of computer networks, a firewall acts like a security guard. Its job is to watch over the flow of information between your computer or network and the internet. It's designed to block unauthorized access while allowing safe data to pass through. Essentially, a firewall helps keep your d 12 min read

Congestion Control Algorithms

• Congestion Control in Computer Networks Congestion control is a crucial concept in computer networks. It refers to the methods used to prevent network overload and ensure smooth data flow. When too much data is sent through the network at once, it can cause delays and data loss. Congestion control techniques help manage the traffic, so al 8 min read
• Congestion Control techniques in Computer Networks Congestion control refers to the techniques used to control or prevent congestion. Congestion control techniques can be broadly classified into two categories: Open Loop Congestion ControlOpen loop congestion control policies are applied to prevent congestion before it happens. The congestion contro 5 min read
• Computer Network | Leaky bucket algorithm In the network layer, before the network can make Quality of service guarantees, it must know what traffic is being guaranteed. One of the main causes of congestion is that traffic is often bursty.  To understand this concept first we have to know little about traffic shaping. Traffic Shaping is a m 11 min read
• TCP Congestion Control TCP congestion control is a method used by the TCP protocol to manage data flow over a network and prevent congestion. TCP uses a congestion window and congestion policy that avoids congestion. Previously, we assumed that only the receiver could dictate the sender’s window size. We ignored another e 5 min read

Network Switching

• Circuit Switching in Computer Network Circuit Switching is a type of switching, in which a connection is established between the source and destination before communication. This connection receives the complete bandwidth of the network until the data is transferred completely. However, circuit switching can be inefficient and costly du 9 min read
• Message switching techniques Switching is the technique by which nodes control or switch data to transmit it between specific points on a network. In message switching the entire message is transmitted without any break from one node to another. There is no direct link present between the sender and the receiver in message swit 4 min read
• Packet Switching and Delays in Computer Network Packet Switching in computer networks is a method of transferring data to a network in the form of packets. In order to transfer the file fast and efficiently over the network and minimize the transmission latency, the data is broken into small pieces of variable length, called Packet. At the destin 7 min read
• Differences Between Virtual Circuits and Datagram Networks Computer networks that provide connection-oriented services are called Virtual Circuits while those providing connection-less services are called Datagram networks. For prior knowledge, the Internet that we use is based on a Datagram network (connection-less) at the network level as all packets from 7 min read

Application Layer:DNS

• Domain Name System (DNS) in Application Layer The Domain Name System (DNS) is like the internet's phone book. It helps you find websites by translating easy-to-remember names (like www.example.com) into the numerical IP addresses (like 192.0.2.1) that computers use to locate each other on the internet. Without DNS, you would have to remember lo 10 min read
• Details on DNS DNS (Domain Name System) allows you to interact with devices on the Internet without having to remember long strings of numbers. Each computer on the Internet has its own unique address, known as an IP address, just like every home has a unique address for sending direct mail. 104.26.10.228 is an IP 5 min read
• Introduction to Electronic Mail Introduction:Electronic mail, commonly known as email, is a method of exchanging messages over the internet. Here are the basics of email:An email address: This is a unique identifier for each user, typically in the format of [email protected] email client: This is a software program used to send, 4 min read
• E-Mail Format Electronic Mail (e-mail) is one of the most widely used services of the Internet. This service allows an Internet user to send a message in a formatted manner (mail) to other Internet users in any part of the world. Message in the mail not only contain text, but it also contains images, audio and vi 3 min read
• World Wide Web (WWW) The World Wide Web (WWW), often called the Web, is a system of interconnected webpages and information that you can access using the Internet. It was created to help people share and find information easily, using links that connect different pages together. The Web allows us to browse websites, wat 6 min read
• HTTP Full Form HTTP stands for HyperText Transfer Protocol. It is the main way web browsers and servers communicate to share information on the internet. Tim Berner invents it. HyperText is the type of text that is specially coded with the help of some standard coding language called HyperText Markup Language (HTM 9 min read
• Streaming Stored Video Streaming of videos involve, storing of prerecorded videos on servers. Users send request to those servers.Users may watch the video from the start till the end, and may pause it anytime, do a forward or reverse skip, or stop the video whenever they want to do so. There are 3 video streaming categor 5 min read
• What is a Content Distribution Network and how does it work? Over the last few years, there has been a huge increase in the number of Internet users. YouTube alone has 2 Billion users worldwide, while Netflix has over 160 million users. Streaming content to such a wide demographic of users is no easy task. One can think that a straightforward approach to this 4 min read

CN Interview Quetions

• Top 50 Plus Networking Interview Questions and Answers for 2024 Networking is defined as connected devices that may exchange data or information and share resources. A computer network connects computers to exchange data via a communication media. Computer networking is the most often asked question at leading organizations such Cisco, Accenture, Uber, Airbnb, G 15+ min read
• Top 50 TCP/IP Interview Questions and Answers 2025 Understanding TCP/IP is essential for anyone working in IT or networking. It's a fundamental part of how the internet and most networks operate. Whether you're just starting or you're looking to move up in your career, knowing TCP/IP inside and out can really give you an edge. In this interview prep 15+ min read
• Top 50 IP Addressing Interview Questions and Answers In today’s digital age, every device connected to the internet relies on a unique identifier called an IP Address. If you’re aiming for a career in IT or networking, mastering the concept of IP addresses is crucial. In this engaging blog post, we’ll explore the most commonly asked IP address intervi 15+ min read
• Last Minute Notes - Computer Networks See Last Minute Notes on all subjects here. OSI ModelPhysical LayerData Link layerNetwork LayerTransport LayerPresentation & Session layerApplication LayerOSI ModelOSI stands for Open Systems Interconnection. It has been developed by ISO– International Organization for Standardization, in the ye 11 min read
• Computer Network - Cheat Sheet A computer network is an interconnected computing device that can exchange data and share resources. These connected devices use a set of rules called communication protocols to transfer information over physical or wireless technology. Modern networks offer more than just connectivity. Enterprises 15+ min read
• Network Layer [mtouchquiz 103] 1 min read
• Transport Layer [mtouchquiz 104] 1 min read
• Application Layer [mtouchquiz 106] 1 min read

Improve your Coding Skills with Practice

What kind of Experience do you want to share?

  Layer 6 Presentation Layer

De/Encryption, Encoding, String representation

The presentation layer (data presentation layer, data provision level) sets the system-dependent representation of the data (for example, ASCII, EBCDIC) into an independent form, enabling the syntactically correct data exchange between different systems. Also, functions such as data compression and encryption are guaranteed that data to be sent by the application layer of a system that can be read by the application layer of another system to the layer 6. The presentation layer. If necessary, the presentation layer acts as a translator between different data formats, by making an understandable for both systems data format, the ASN.1 (Abstract Syntax Notation One) used.

OSI Layer 6 - Presentation Layer

The presentation layer is responsible for the delivery and formatting of information to the application layer for further processing or display. It relieves the application layer of concern regarding syntactical differences in data representation within the end-user systems. An example of a presentation service would be the conversion of an EBCDIC-coded text computer file to an ASCII-coded file. The presentation layer is the lowest layer at which application programmers consider data structure and presentation, instead of simply sending data in the form of datagrams or packets between hosts. This layer deals with issues of string representation - whether they use the Pascal method (an integer length field followed by the specified amount of bytes) or the C/C++ method (null-terminated strings, e.g. "thisisastring\0"). The idea is that the application layer should be able to point at the data to be moved, and the presentation layer will deal with the rest. Serialization of complex data structures into flat byte-strings (using mechanisms such as TLV or XML) can be thought of as the key functionality of the presentation layer. Encryption is typically done at this level too, although it can be done on the application, session, transport, or network layers, each having its own advantages and disadvantages. Decryption is also handled at the presentation layer. For example, when logging on to bank account sites the presentation layer will decrypt the data as it is received.[1] Another example is representing structure, which is normally standardized at this level, often by using XML. As well as simple pieces of data, like strings, more complicated things are standardized in this layer. Two common examples are 'objects' in object-oriented programming, and the exact way that streaming video is transmitted. In many widely used applications and protocols, no distinction is made between the presentation and application layers. For example, HyperText Transfer Protocol (HTTP), generally regarded as an application-layer protocol, has presentation-layer aspects such as the ability to identify character encoding for proper conversion, which is then done in the application layer. Within the service layering semantics of the OSI network architecture, the presentation layer responds to service requests from the application layer and issues service requests to the session layer. In the OSI model: the presentation layer ensures the information that the application layer of one system sends out is readable by the application layer of another system. For example, a PC program communicates with another computer, one using extended binary coded decimal interchange code (EBCDIC) and the other using ASCII to represent the same characters. If necessary, the presentation layer might be able to translate between multiple data formats by using a common format. Wikipedia

• Data conversion
• Character code translation
• Compression
• Encryption and Decryption

The Presentation OSI Layer is usually composed of 2 sublayers that are:

CASE common application service element

Sase specific application service element, layer 7   application layer, layer 6   presentation layer, layer 5   session layer, layer 4   transport layer, layer 3   network layer, layer 2   data link layer, layer 1   physical layer.

• For Individuals
• For Businesses
• For Universities
• For Governments
• Online Degrees
• Join for Free

Understanding the Presentation Layer: A Beginner’s Guide

Discover how the presentation layer functions as the sixth layer in the OSI model and how experience in this area might benefit a networking career.

The presentation layer is the sixth layer within the open systems interconnection (OSI) model. It is located next to the application layer and translates data to transmit from or send to the application layer. It does this by converting, compressing, encrypting, and serializing data into different forms that can be more easily transmitted through a network. 

Read more to explore the basic function of each layer in the OSI, how the presentation layer works to translate data for transmission, and the various protocols it uses in this process.

Layers in network models

The open systems interconnection (OSI) model is a framework for the structure of data transmission through networks. The OSI model has seven layers, but not each is necessarily implemented as the model suggests for the functioning network. The layers are an abstract view of how a network functions so that network administrators or technicians can more easily identify where issues in the work occur. The seven layers that make up the OSI are:

Layer 7: The application layer , where users interact with applications connected to the internet

Layer 6: The presentation layer , where data is partially encrypted and translated into a transmittable format

Layer 5: The session layer: which controls ports and sessions and maintains connections between devices

Layer 4: The transport layer , which uses TCP and other protocols to assemble and sequence packs in the order they are to be sent out 

Layer 3: The network layer , which routes packets by telling them which physical path to take between routers and switches 

Layer 2: The data link layer , which works with layer 2 switches, hubs, and other devices and splits into the MAC layer 

Layer 1: The physical layer , which transmits the data over the hardware components of the network, such as cables and the network architecture 

Read more: 6 Network Certifications for Your IT Career in 2024

What does the presentation layer do?

The presentation layer translates data from the application layer for transmission to the application layer for use by the intended device. It makes the data readable to and from the application layer. This layer is where encryption occurs when data is sent from the application layer, and when decryptions occur, it is sent back to the application layer. It identifies the receiving data to know it and decrypts data to the proper receiving device in a process known as authentication. 

When sending data to layer 5, the session layer compresses data to save storage space and speed transmission. Serializing complex structures also helps translate data structures into different formats that are easier to transmit. This process converts complex data structures into easily transmittable bytes in a format that all networks can read. The presentation layer uses abstract syntax notation (ASN.1). 

Abstract syntax notation (ASN.1)

ASN.1 is the international standard for representing, encoding, and transmitting data structures across networks. It uses abstract syntax to indicate data structures universally and transfer syntax to describe the bit encoding of the ASN.1 object. It also provides a standardized set of rules for device encoding processes, making it non-ambiguous and readable by programmers and network engineers. 

When an application sends data, the presentation layer converts the data object into ASN.1 for transmission across the network. Upon reception of the intended device, the presentation layer converts the data out of ASN.1 and back into the original data object on the intended device. This process is useful because it follows the structure of other programming languages, like C. 

External data representation (XDR)

External data representation (XDR) is a less complex but less powerful alternative to ASN.1. For XDR to function, network peers must know the defined types involved in transmission instead of the universal method of ASN.1. XDR only uses data streams of 4 bytes, in the order in which the network receives them. All of these simpler processes give XDR a speed advantage over ASN.1. 

Additional presentation layer protocols

The presentation layer may use a series of additional protocols depending on the needs of the application layer. These protocols include:

Apple filing protocol (AFP): Developed by Apple, this protocol allows users of multiple Mac computers to share files over a network easily.

Independent computing architecture (ICA): Developed by Citrix, this protocol allows users from different locations to house data in one central virtual server.

Lightweight presentation protocol (LPP): This smaller, simpler non-ISO presentation protocol allows ISO presentation services over UDP and TCP networks.

NetWare core protocol (NCP): Developed by Novell, this protocol describes routines and primitives allowing client-server communication on Novell NetWare operating systems and others, such as Linux, UNIX, and Windows NT.

Network data representation (NDR): This protocol encodes data in a distributed computing environment (DCE) by placing an architecture tag before each message and using a compiler to generate stubs.

Who uses OSI and the presentation layer?

The OSI model is a framework that IT professionals, such as network administrators and cybersecurity analysts, use to diagnose network or security problems. The OSI layers give network admins a working structure to diagnose whether network issues occur on the application end, host device, or network. Since the presentation layer works with encryption and decryption, it is vulnerable to attacks, making it an important networking aspect for cybersecurity analysts to understand. 

Understanding the OSI and presentation layer is also useful for software designers, as it allows them to understand how their software interacts with the network when it makes network requests or sends data. 

Read more: What is the CCNA? An Entry-Level Networking Certification

How to get started in networking

Understanding the OSI model is important for anyone needing to troubleshoot a network. It provides a framework for understanding how the bitstream flows through various networking aspects. 

Network technicians are an entry-level position that must diagnose and analyze network issues and work with computer problems that may arise from a network or device issue. To become a network technician, you typically need at least an associate degree, and some employers may require you to have specific IT certifications that validate your skills. In this role, you'll often work under network administrators who also often start as network technicians. Employers typically require a bachelor’s degree in IT or computer engineering to advance to a network administrator. The average annual salary for a network technician is $62,243 [ 1 ].

Understanding and having various methods to troubleshoot networking issues is an essential skill for network technicians to develop to be effective in their work. You might also consider developing technical support skills and gaining experience with LINUX, VPN, and other networking hardware systems.

Getting started with Coursera

The presentation layer is a key part of a functioning OSI system, which gives structure to data moving through networks. Professionals who want to work in network security typically have experience with presentation layers and other OSI components. Ready to gain relevant skills in networking to succeed in an entry-level career? Try the Google IT Support Professional Certificate on Coursera. With this Professional Certificate, you can gain troubleshooting, computing, and networking skills to prepare you for an entry-level career. Additionally, if you want to understand networking and prepare for an entry-level cybersecurity professional career, try the Google Cybersecurity Professional Certificate on Coursera. 

Article sources

Glassdoor. “ Network Technician Salary , https://www.glassdoor.com/Career/network-technician-career_KO0,18.htm#:~:text=%2461%2C708,Base%20Pay.” Accessed October 21, 2024

Keep reading

Coursera staff.

Editorial Team

Coursera’s editorial team is comprised of highly experienced professional editors, writers, and fact...

This content has been made available for informational purposes only. Learners are advised to conduct additional research to ensure that courses and other credentials pursued meet their personal, professional, and financial goals.