Data link layer data link layer objectives specific. You can find them according to your branch and subject in the below link national mission on education through ict this was initiated by iit madras. Oct 09, 2019 nptel has changed the links of pdf lecture notes since august 2019. A s we talked earlier in the article osi model and its 7 layers, the data link layer is the penultimate or the second lowermost in the osi model. Nov 05, 2012 cisco ccna 01 chapter 07 data link layer. Link channel complexity causes the logical link and mediaaccess control sublayers split. The endtoend argument becomes clear at the datalink layer. You dont really need to study the internals of ethernet to make a production network operate, so if youre inclined, do that on your own time. Data link layer is the second layer in osi reference model and lies above the physical layer.
Well be talking about bridges, switching and vlans with the goal of discovering how they interact in this part of networking 101. The network layer is interested in getting messages to the corresponding network layer module on an adjacent machine. Data structures and algorithms nptel online videos. Nptel video lectures, iit video lectures online, nptel youtube lectures, free video lectures, nptel online courses, youtube iit videos nptel courses.
In this paper, data link control in data communication is discussed. This band is reserved for that station for all the time. Link layer and local area networks in this chapter we examine the data link layer its services, the principles underlying its operation, and a number of important data link layer protocols. Data link layer silvia giordano ica, epfl the datalink layeris responsible for transferring a datagram across an individual link. Cn lecture notes veer surendra sai university of technology. The remote network layer peer should receive the identical message generated by the sender e.
Examples of linklayer protocols include ethernet, token ring, fddi, and ppp. Download cbse notes, neet notes, engineering notes, mba notes and a lot more from our website and app. Data framing encapsulation of the packet or message received from the network layer to form frames. The frequency bands of different stations are separated by small bands of unused frequency. Computer science and engineering data communication nptel. Data link layer design issues providing a welldefined service interface to the network layer. Synchronize and initialize send and receive sequence numbers with its peer at the other end of the communications channel. Computer networking and management lesson 5 the data link layer. Data packets are framed and addressed by this layer, which has two sublayers. Regulating the flow of data so that slow receivers are not swamped by fast senders 4 for this, the data link layer takes the packets it gets from the network layer and encapsulates them into frames for transmission. Data link layer dlc responsible for reliable transmission of packets over a link framing. Data link layer protocols the data link layer provides service to the network layer above it. Datagram from network layer is encapsulated into a linklayer frame for transmission over physical medium.
Introduction and course outline data communication. The data link layer uses open operations for allocating buffer space, control blocks, agreeing on the maximum message size, etc. The data link layer in the internet a home personal computer acting as an internet host. The data link layer offers transmission service to the network layer. Datagram from network layer is encapsulated into a link layer frame for transmission over physical medium. You will find all pdf s and also as mp3 file for all video lectures which are in nptel. The receiving data link layer s windo w co rrespond s to the frames it may accept. Lecture notes data communication networks electrical. Logical link control llc sub layer defines the functions to be needed for establishment and control of logical links between local devices in. Nov 15, 2017 you will find all pdf s and also as mp3 file for all video lectures which are in nptel. Typically, the network layer adds its own header to the packets received from the transport layer. Iso 118981, road vehicles controller area network can part 1. This layer is one of the most complicated layers and has complex functionalities and liabilities. Computer science and engineering computer networks nptel.
The data link layer s first sublayer is the media access control mac layer. Linkchannel complexity causes the logicallink and mediaaccess control sublayers split. Apr, 2016 a s we talked earlier in the article osi model and its 7 layers, the data link layer is the penultimate or the second lowermost in the osi model. Our new crystalgraphics chart and diagram slides for powerpoint is a collection of over impressively designed data driven chart and editable diagram s guaranteed to impress any audience. The link layer packet frame the link layer is responsible for framelevel nodetonode communication. These functions include providing a welldefined interface to the network layer, framing, dealing with transmission errors and regulating the flow of frames. Nptel has changed the links of pdf lecture notes since august 2019. How to download notes directly in pdf format from nptel. Link layer and local area networks in this chapter we examine the data link layerits services, the principles underlying its operation, and a number of important data link layer protocols. Introduction dlc is the service provided by the data link layer of function defined in the open systems. Data structures and algorithms nptel video lectures naveen garg, nptel video lectures, nptel online courses, youtube iit videos nptel courses. This header provides the information needed for routing e. At the receiving end, data link layer picks up data from hardware which are in the form of electrical signals, assembles them in a recognizable frame format, and hands over to upper layer.
Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Following are functions and tasks performed by the data link layer. Data structures and algorithms nptel online videos, courses. The three main functions of the data link layer are to deal with transmission errors, regulate the flow of data, and provide a well. The ethernet a local area network, data link layer and. The data link layer is the second layer in the osi model. Shivkumar kalyanaramans online audio and video lectures and classes on networking. Link nodetonode framebyframe 10110100100101010 the link layer packet frame the link layer is responsible for framelevel nodetonode communication. Regulating the flow of data so that slow receivers are not swamped by fast senders. The endtoend argument becomes clear at the data link layer. D 2 previous lecture the network is organized into layers 3 this lecture link layer network layer forwarding routing hierarchical addressing and routing 4 link layer problem.
Functions of llc and mac sublayers of data link layer. The data link layer provides data reliability and provides tools to establish, maintain, and release data link connections among the network nodes. Hd of a coding scheme for m bit data all the 2m possible combinations are legal but not all the 2n codewords are used in a coding scheme algorithm to compute the check bits some of these codewords are legal and others are illegal for eq. Logical link control llc sub layer defines the functions to be needed for establishment and control of logical links between local devices in the network. Digital image processing nptel online videos, courses iit. Data link layer connecting upper layer services to the media the data link layer exists as a connecting layer between the software processes of the layers above it and the physical layer below it.
Data link layer works between two hosts which are directly connected in some sense. Layer 2, the data link layer, is where ethernet lives. Computer networking and management lesson 5 the data. Demo lecture 46 data link layer overview lecture 47 data link layer basic concepts lecture 48 data link layer ethernet lecture 49 data link. The data link and physical layer is where network abstractions are implemented. Data link control in data communication iosr journals. This presentation covers the datalink layer of the networks lecture slides from the 3rdyear module on computer networks at the university of birmingham, uk. How to download all of the lectures in pdf for a course in. Digital image processing nptel online videos, courses. Internet router architecture 8 router 3layer physical, datalink, network device, with 3 key functions. The data link layers first sublayer is the media access control mac layer.
This post gives a brief overview of the two sublayers of the data link layer, namely llc logical link control and mac media access control. Then add the segments and use the sum as redundant bits. Jan 30, 2015 data link layer design issues providing a welldefined service interface to the network layer. Worlds best powerpoint templates crystalgraphics offers more powerpoint templates than anyone else in the world, with over 4 million to choose from. Nptel provides elearning through online web and video courses various streams. The receiving data link layers windo w co rrespond s to the frames it may accept. Iit nptel data structures, algorithms and software engineering video lectures, lessons and tutorials video lessons on algorithms, binary search trees, hashing data structures etc. Linklayer retransmission of corrupted frames suny at buffalo. The ethernet a local area network data link layer and physical layer specifications digital equipment corporation intel corporation xerox corporation maynard, ma santa clara, ca stamford, ct version 2.
The data link layer is used for the encoding, decoding and logical organization of data bits. The control done by the data link layer is data link control. These unused bands are called guard bands that prevent station interferences. Ppt data link layer powerpoint presentation free to. Logical link control llc and media access control mac. Chart and diagram slides for powerpoint beautifully designed chart and diagram s for powerpoint with visually stunning graphics and animation effects. We learn that the basic service of the data link layer is to move a networklayer datagram from one node host or router to an adjacent node. Pdf security issues in the data link layer are not properly explained while network security problems in other layers of osi model are studied and addressed. Providing a welldefined service interface to the network layer. While the first diagram shows the theoritical structure, the second diagram shows typical frame contents the generic frame structure consists of a mac header, followed by a llc header, then the actual l3 datagram to be carried to the next hop and then a mac trailer, as shown in the top portion of the above diagram. Widespread deployment worldwide cellular subscribers 1993.
The data link layer functionality is usually split it into logical sublayers, the upper sublayer, termed as llc, that interacts with the network layer above and the lower sublayer, termed as mac, that interacts with the physical layer below, as. The datalink and physical layer is where network abstractions are implemented. The main principle is to divide the data into segments of n bits. We learn that the basic service of the data link layer is to move a network layer datagram from one node host or router to an adjacent node. Highlevel data link control hdlc sequence is 01111110 special pattern may appear in payload solution. Ppp point to point protocol 2 a simplified phase diagram for bring a line up and down. The datalink layer has responsibility of transferring datagram from one node to adjacent node over a link goto top link layer and local area networks in this lesson we examine the data link layer its services, the principles underlying its operation, and a number of important data link layer protocols. A link isthe communication channels that connect two adjacent hosts or routers. Jan 12, 2009 this presentation covers the datalink layer of the networks lecture slides from the 3rdyear module on computer networks at the university of birmingham, uk. It mainly does three controls that are its functions and their advantages. Nptel data structures nptel video lectures from iits and.
Ppp point to point protocol the ppp full frame format for unnumbered mode operation. Physical layer delivers bits of information to and from data link layer. Data link layer is responsible for converting data stream to signals bit by bit and to send that over the underlying hardware. Data link layer and physical signalling 3 terms and definitions for the purposes of this document, the terms and definitions given in iso 117831 apply. Fdma in fdma, the available bandwidth is divided into frequency bands.
Any frame falling out side the windo w is di sca rded without comment. Winner of the standing ovation award for best powerpoint templates from presentations magazine. As such, it prepares the network layer packets for transmission across some form of media, be it copper, fiber, or the atmosphere. The datalink layer offers transmission service to the network layer. Data link layer hides the details of underlying hardware and represents itself to upper layer as the medium to communicate. Network layer and ip protocol cse 32, winter 2010 instructor. Data networks lecture 1 introduction mit opencourseware. Theyll give your presentations a professional, memorable appearance the kind of sophisticated look that todays audiences expect. Online video lectures class, lessons on computer networking. The physical layer provides only a raw bitstream service between computers.