Encapsulation, which consists of isolating a set of data and opera tions on those data within a module and providing precise speci. This part explains hdlc highlevel data link control protocol and encapsulation method in detail with examples including step by step configuration guide. Add the destination and source network layer addresses to the datathe network layer creates the network header, which includes the network layer addresses, and places the data behind it. Data encapsulation data encapsulation, sometimes referred to as data hiding, is the mechanism whereby the implementation details of a class are kept hidden from the user. Identify the appropriate media, cables, ports, and connectors to connect cisco network devices. The user can only perform a restricted set of operations on the hidden members of the class by executing special functions commonly called methods. Basically, you will encapsulate data to hide it from you, other programmers, and users that will use or e.
When referring to networking, encapsulation is the process of taking data from one protocol and translating it into another protocol, so the data can continue across a network. On the receiving machine, the encapsulation is reversed as. Cisco certified network associate ccna training by to prepare for exam 640802. Data encapsulation, protocol data units the tcpip guide. Learn how data is encapsulated and deencapsulated when it passes through the layers of osi and tcpip models. Encapsulation is a process to hide or protect a process from the possibility of outside interference or misuse of the system while simplifying the use of the system itself, also makes one type of network data packets to other data types. Data encapsulation and the tcpip protocol stack system. The picture below is an example of a simple data transfer between 2 computers and shows how the data is encapsulated and decapsulated. The key difference between encapsulation and decapsulation is that, in encapsulation. A protocol in the lower layer receives data from the protocol of upper layer, then the process of encapsulation starts here.
This document contains the specification of the ethernet, a local area network developed jointly by digital equipment corporation, intel corporation, and xerox corporation. Each layer adds its own header data link protocols also add a trailer to the data supplied by the higher layer. Pdu used for the physical transmission of binary data over media. This tutorial explains data encapsulation and deencapsulation in detail with examples. The reverse process of encapsulation or decapsulation occurs when data is received on the destination computer. Data representation data representation is defined as the methods used to represent information in computers. For example, a tcpip packet contained within an atm frame is a form of encapsulation. The computer in the above picture needs to send some data. Data encapsulation, protocol data units pdus and service data units sdus protocols are what describe the rules that control horizontal communication, that is, conversations between processes that run at corresponding layers within the osi reference model. The term encapsulation describes a process of putting headers and sometimes trailers around some data.
Pdf high performance encapsulation and networking in. It can be literally defined as the process of opening a capsule, which, in this case, refers to encapsulated or wrappedup data. Data encapsulation is the process of breaking down information into smaller manageable chunks before it is transmitted across the network. The encapsulated data is called pduprotocol data units. The resources such as printers, file servers, scanners, and internet are easily sharable among computers. Lans are composed of inexpensive networking and routing equipment.
It sometimes referred to as data hiding that prevents the user to access the implementation details. As the data moves up from the lower layer to the upper layer of tcpip protocol stack incoming transmission, each layer unpacks the corresponding header and uses the information contained in the header to deliver the packet to the. What is encapsulation and deencapsulation information that is transmitted over a network must undergo a process of conversion at the sending and receiving ends of the communication. In objectoriented programming data encapsulation is concerned with. Predict the data flow between two hosts across a network. This process can be explained with the fivelayer tcpip model the link layer of the tcpip model is sometimes divided into two layers, data link and physical, hence the five. Encapsulation and deencapsulation flashcards quizlet. This process can be explained with the fourlayer tcpip model, with each step describing the role of the layer. Thus, encapsulation is the process of enclosing one type of packet using another type of packet. The ethernet a local area network, data link layer and.
Introduction the open systems interconnection osi model is a reference tool for understanding. One important piece of information to keep in mind is that data flows 2 ways in the osi model, down data encapsulation and up data decapsulation. For example, the term layer 3 pdu refers to the data encapsulated at the network layer of the osi model. The data is encapsulated with protocol information at each osi reference model layer when a host transmits data to another device across a network.
The data is contained in a container for safety purpose, to hide or protect the data from possible outside interference or from misuse of it. The data encapsulation is only useful to the same layer at the other end. Data encapsulation keith gebhardt 4 chapter 1 to understand the data encapsulation process, we need to get you reacquainted with some of the important basic networking topics first. In networking model, the terms encapsulation and deencapsulation refer to a process in which protocol information is added to the data and removed. Data encapsulation is the most important concept to grasp when programming with objects. In the following sections well be looking at each layer in more specifics. In computer networking, the term encapsulation is used to refer to the process of each layer at the sending computer adding its own header information, in the form of metadata to the actual payload data. Here is a graphical representation of the pdus in the. Data encapsulation is an object oriented programming concept that bind a group of related properties, functions, and other members are treated as a single unit. As you know osi works in layer as the data moves down it is encapsulated by each layer. Data encapsulation led to the important oop concept of data hiding. Data encapsulation is a mechanism of bundling the data, and the functions that use them and data abstraction is a mechanism of exposing only the interfaces and hiding the implementation details from the user. In computer networking, encapsulation is a method of designing modular communication protocols in which logically separate functions in the network are abstracted from their underlying structures by inclusion or information hiding within higher level objects the physical layer is responsible for physical transmission of the data, link encapsulation allows local area networking, internet.
The term encapsulation is used to describe a process of adding headers and trailers around some data. In objectoriented programming languages, and other related fields, encapsulation refers to one of two related but distinct notions, and sometimes to the combination thereof a language mechanism for restricting direct access to some of the objects components a language construct that facilitates the bundling of data with the methods or other functions operating on that data. Data travels on a network in the form of packets, bursts of data with a maximum length imposed by the link layer. The reverse of data encapsulation is decapsulation, which refers to the successive layers of data being removed essentially unwrapped at.
The user can only perform a restricted set of operations on the hidden members of the. The encapsulation on a router serial interface must be configured to ensure the correct encapsulation method is used. Introduction to network hardware o switches o routers. Generally, encapsulation is a process by which a lowerlayer protocol receives data from a higherlayer protocol and then places the data into the data portion of its frame. However, the notion of data encapsulation is critical to creating modular, flexible networks. Data encapsulation refers to sending data where the data is augmented with successive layers of control information before transmission across a network. For example, a tcpip packet contained within an atm frame is a form o. At every layer except layer one these communications ultimately take the form of. The ethernet specification is the result of an extensive collaborative effort of the three corporations, and several years of work at xerox on an earlier prototype ethernet. Data encapsulation page 3 in java, data encapsulation is enforced classbyclass at compile time r ather than objectbyobject during runtime.
What is the main benefit of encapsulation in networking. We will start off by discussing the network architecture models. Data encapsulation allows devices to communicate, and therefore, it is completely necessary to learn. As we are sending larger amount of data so in transport layer data need to be segmented with proper sequence. Intro data encapsulation introduction to osi layer model. Data encapsulation in the osi model in the previous lesson we have learned that the term encapsulation describes the process of putting headers and sometimes trailers around some data. Understanding data encapsulation the sending and receiving of data from a source device to the destination device is possible with the help of networking protocols when data encapsulation is used. Data encapsulation, also known as data hiding, is the mechanism whereby the implementation details of a class are kept hidden from the user. Figure 29 depicts the encapsulation process and shows. Like with the tcpip layers, each osi layer asks for services from the next lower layer. The data is encapsulated with protocol information at each osi reference model layer.
Difference between encapsulation and decapsulation. Encapsulation occurs when a protocol that is on the lower layer receives data from the protocol that is at a higher layer and put the data into a data format. The packet is the basic unit of information transferred across a network, consisting, at a minimum, of a header with the sending and receiving hosts addresses, and a body with the data to be transferred. The process of adding control information as it passes through the layered model is called encapsulation. When the data is passed from the network layer to the data link layer for transmission over the physical link, the data link layer creates a frame by adding the necessary checks and controls around the network layer data.
An example of a clientserver network would be windows xp workstations accessing files off of a windows 2003 server. The wrapping of private data in classes in objectoriented programming. Each layers header information would be interpreted and acted upon by a peer layer in another machine. As only the same layer or we call peer layer can read the data it strips the header that was attached extract useful info and sends it to upper layer. Data encapsulation is one of the three fundamental pillars of the objectoriented paradigmthe other two are inheritance and polymorphism. Protocol data units and encapsulation for application data to travel uncorrupted from one host to another, header or control data, which contains control and addressing information, is added to the data as it moves down the layers.
For example, here is what happens when you send an email using your favourite email program such as outlook or thunderbird. The conversion process is known as encapsulation and deencapsulation of data. Data application data presentation layer data session layer. There are several advantages to the clientserver architecture. Data communication and computer network 4 lan provides a useful way of sharing the resources between end users. Data encapsulation in the osi model ccna geek university. Data and services are now centrally located on one or more servers, consolidating the management and security of that data.
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