Computer Networks For Beginners | IT Networking Fundamentals | Edoreal Learning Solutions | Skillshare

Computer Networks For Beginners | IT Networking Fundamentals

Edoreal Learning Solutions

Play Speed
  • 0.5x
  • 1x (Normal)
  • 1.25x
  • 1.5x
  • 2x
14 Lessons (1h 2m)
    • 1. Introduction to CN

    • 2. Types of communication and types of networks

    • 3. Internet

    • 4. Network topologies

    • 5. Protocols and Standards

    • 6. Types of Network Models

    • 7. User support layers in OSI model

    • 8. Network support layers in OSI model

    • 9. TCP/IP model

    • 10. Addressing in computer Networks

    • 11. Introduction to Physical Layer

    • 12. Multiplexing

    • 13. Transmission Media

    • 14. Fiber optic cables

20 students are watching this class

About This Class

Computer network connects two or more autonomous computers. The computers can be geographically located anywhere. Computer networks have opened up an entire frontier in the world of computing called the client/server model.

By choosing this course, you will come to know about the basics of computer networks, types of network models, Types of layers in each model, types of devices, types of networks and what is internet etc. You will also learn about the history of internet, history of these computer networks and who are the scientist involved in developing these technologies.

You will learn the following topics with this course

  1. Introduction to computer networks
  2. Networking devices like switches
  3. Learn about LANs and WANs
  4. Subnets, layers, models
  5. Understand OSI Model
  6. Understand concept of TCP/IP protocol
  7. Understand what is Physical Layer
  8. Learn about Multiplexing
  9. Transmission media in Physical layer
  10. Fiber optic cables
  11. Basics of networks and its introduction

This course is targeted at Computer science engineering students who are passionate about networks and security, beginners who want to know about how internet and communication works between computers. Basic knowledge of Computer Hardware and Software is required to learn this course.


1. Introduction to CN: hello. In this course, we discuss computer networks in detail. Why waiting? Let's dive in these days we use computer networks daily because off its advantages. For example, let's say we need to send a file to our friend who is miles away from us. Unlike traditional career service, we could send that distill file instantaneously through computer networks. Despite the miles distant able to exchange data from all points in the world quickly and accurately is only possible through computer networks. Let's see Water Computer Network Ease. A computer network is just an interconnection off autonomous computers that transmit data using electrical signalling. This course explains the fundamentals of computer networks in a simple and understandable way. The basic components of competent attacks are called coast On subjects they hosted an end system that sends and receives messages. A computer in the network can be called as a host. The host, or node in the network can also be a mobile device switch router. Extra submit is a collection of switching elements on transmission lines. Switching elements are nothing bad. Specialized computers such as routers and switches Network provider, a telephone company operates this subject purpose of the subcommittees to carry messages from host to host. The more recent meaning off sub Nitties logical subdivisions are sub networks off a bigger network. Let's see some basic switching elements off computer networks. Hub, switch and router are the basic switching elements. Hobbies. A simple networking device which connects all network dividers on an internal network. It has multiple ports that, except Internet connections from the devices. It doesn't know the exact location of the destination device to where the data must be sent . So if PC one sends a message to PC three, the message will be broadcasted by the hub to all the devices that are connected to the hub . It creates secular issues, unnecessary traffic, westerns of bandwidth extra. That's why it's which is our preferred over hubs. The switch is very similar to hub in connecting dividers on an internal network. The only difference is the switch knows precisely where the data to be sent. It can detect the physical or MCA disease off the devices that are connected to the switch . So, unlike Hub, the data transmitted from a PC would go to the intended PC in the network with help off a switch hub under switch are used to exchange data within the same network cannot transfer data outside the network that is on the Internet To exchange data outside their own network . We need a device that is capable off reading I p addresses. That is read. The rotor comes in and router routes the data from one network to another using I P addresses. So the data from a PC in the first network goes to the switch. Then that order takes the data from the sweet. On far was the data to the switch in the second network and so on until it reaches the destination. 2. Types of communication and types of networks: Let's see the types of communication in computer networks. Communication can occur in three days, and they are going to point broadcasting on multi casting in point to point. As the name suggests to computers directly communicate with each other. That is 1 to 1, whereas in broadcasting, one computer sends data to all notes in the network. For example, distributing weather reports are live radio programs. Broadcasting a message is vestal because some of the receivers might not be interested in the message. Multi casting is nothing but sending messages to, well defend Group off notes. But not all the notes. For example, streaming live video only to the subscribed of yours categories. Off networks In general, there are two primary categories off networks. Local area network on wide area. Network networks off a size in between are typically referred to as Metropolitan Area Network, local area network, Local area network, or LAN, is a private network. Off personal computers are consumer electron ICS that share a common communication medium, such as cables or wireless connection. Lancer confined to a small geographic area. Such a single office or a building lance owned by companies are called enterprise networks . All computers in the land communicate through a hub or switch. The most common type of wide land is the Internet. Here we can see a simple switch. The Internet. Each computer speaks the Internet protocol and connects to a box called a switch standard technologies used in the land or return it on WiFi Weightless Lancer. The newest evolution in land technology, the standard for wireless Lan sees popularly known as WiFi comfort the wireless networks. Wide lands exceed them in all dimensions of performance. Many lands used wireless technologies that are built into smartphones, tablet computers and laptops with the help of heart sports. Why do you Network? A van is normally referred to as a network, which spans over a large geographic area that may comprise a country, a continent or even the whole world. Van provides long distance transmission of data. For example, take three officers from three different cities, which are located far away from each other. The three lands can be connected using transmission lines on switching elements, that is, routers to have communication between all the computers. On this is called a van in a van. The hosts on sub nets are owned and operated by different people. Voters in a van usually connect different kinds of networking technology. So the networks in these offices, maybe a switch of the the net on the transmission lines can be sown. It links. So if van maybe before toe as an Internet work than can be circular switched or packet switch on it can use fiber links or wireless technologies. For example, satellite communication. Let's see the two other variations in once. Instead of having dedicated lines, the company may want to interconnect all its branches virtually using underlying capacity off the Internet, which is called as VP in or what your private network And it is also a type of van. Instead of having dedicated lines on VP in, the company can approach a network service provider or telecom company toe connect all its branches, which can also be a van Metropolitan Area Networks, a metropolitan area network. Our man is a network which is bigger than land but smaller than van. It typically covers the area inside a town or a city. It is designed for those who need a high speed connectivity. A good example. Off man is a part off a telephone company network that can provide a high speed digital subscriber line, or DSL, to the customer. Recent developments in high speed wireless Internet have resulted in another type of man, which has been standardised as I Triple E eight, No. 2.16 on He's popularly known as Why Max. 3. Internet: in the network. Many types of networks are available in the world with the different hardware and software . These incompatible networks must be connected to achieve communication between people connected to different networks. Internet book or Internet. He's nothing but the interconnected collection Off networks. The most important Internet is called the Internet Note Uppercase Letter I. The Internet is a collaboration off millions off interconnector networks History of the Internet in mid 19 sixties, Advanced Research Projects Agency are are per in the department Off Defense Off Us A. Wanted to develop a command and control network that could survive a nuclear attack on the investors who funded in this project, wanted to share the findings between researchers that could eliminate the duplication of efforts and reduce costs. In 1967 at an Association for Computing Missionary, or ACM, AARP represented its idea for our planet, a small network off connected computers. The core idea was that each host computer would be attached to a specialized machine called Interface message processor. Are I M P. All I am piece need to be connected to one another on each MP should be able to communicate with another. I am piece as well as with its own attracted host. By 1969 Arpanet was a reality. Four notes at four universities were connected by the MPs to form a network Network control protocol provided communication between the hosts in the network host is nothing but a computer. In 1972 Bob Kahn and Vint Cerf, both of whom were part of the core Arpanet group, collaborated on a project named the Internet ING Project. Shortly after that, authorities decided to split TCP into two protocols transmission control protocol TCP on inter networking protocol, i P by mid 19 eighties and a self or national science foundation built a new backbone to connect it supercomputing centers to some regional networks with 56 k bps slings, a backbone is a part off a computer network that interconnects various pieces off network, providing apart for the exchange off information between different lands or sub networks. Later, NSF upgraded its backbone to 4 48 k bps and then to 1.5 amperes, which allowed the network connection to thousands off universities, research labs, libraries, museums, ex cetera. In 1990 the 1.5 MBPs links were upgraded to fortify and appears later. NSF created naps or network access points to ensure regional network could communicate with every other regional network. Then many other countries and regions build national research networks. In the early 19 nineties, the Internet has grown explosively with the emergence of World Wide Web, the architecture of the Internet, the Internet has gone through so many phases since 19 sixties. Today, the Internet we experience is the result off decades off innovation on combination off many technologies. So it became complex over the years it is made up off. Many violate DEA on local area networks, joined by various devices, switching stations, routers and so on. Today we use services off the Internet. Service providers are eyes piece to get an Internet connection. The Internet uses Ice peanut works to contact enterprise networks. Home networks on many other networks, all eyes piece are connected in order to deliver the Internet services to the end user. There are international service providers, national service providers, regional service providers on local service providers. The Internet today is not owned by any single person. Our government international ice piece connect all the nationalized piece. The national Internet service providers are backbone networks created and maintained by specialized companies. All these nationalized piece are connected by massive fitting stations called network Access Points on Naps. The regionalized piece in turn, take services from nationalized piece on provide services to localize piece. Finally, the localized peace offer Internet services to the end users. This is how the typical Internet connects the whole world. 4. Network topologies: physical topology. There are two types of connections. Find two point on multi point. We have already seen point to point. A multi point connection is one in which more than two specific devices share a single link . Physical topology means having a truck is laid out physically. The structural representation off the relationship off all the links on linking devices to one another is referred to as the topology. Off a network. There are four basic apologies. Mesh Star Bus on Dring Messed Apology. Here Every device has a dedicated point to point link to every other device. The Tom dedicated means the link carries traffic only between the two devices it connect. To find the number of physical links with a node, we first considered that each note must be connected to every other note, meaning that every note must be connected to and minus one note. If each physical link alos communication in both directions are duplex mode, we can say that in a messed apology we need and into and minus one by to duplex mode dealings. To accommodate those links, every device on the network must have, and minus one I reports to be connected to other and minus one stations. Advantages. No traffic problem. Because each connection can carry its own data load, it is robust. If one link becomes unusual, it doesn't cut up the in that system. It has the advantage of privacy or security. Because of the dedicated line on Lee, the Internet recipients sees the message point to point links make fault identification easy. We can find the precise location off the fault. Disadvantages, installation and re connection are difficult because all the vases must be connected to one another. The bulk of the whiting occupies the available space. The hardware required to connect each link. Our I reports and cable can be expensive. One of the practical examples off a messed apologies. The connection off original telephone offices in which each regional office needs to be connected to every other regional office. Start apology. Every device in star topology has dedicated point to point link only to a central connection point. Usually called a hub or switch, the devices are not directly connected to each other like a mess. Topology. A star topology doesn't alot direct traffic between the devices. The central Point acts as an exchange. One device wants to send data to another. It sends the data to Central Point, which then sends the data to another connected device. Advantage is less expensive than a messed apology because each device needs only one bling on one, I report, it is easy to install and reconfigure. It is robust because if one link failed, only that link is affected. Easy for identification. These advantages. The whole topology depends on a single device. The hub. If the hub goes down, the whole system is dead. The Star topology is widely used in local area networks. High speed lands usually use a star. Topology with a central hub must apology the mash and start apologies used point to point connections. A bus topology, on the other hand, is multi point one. Long cable is used to link all the devices in the network. Each device is connected to attack. Attach it to the long cable. As a signal travels along the cable, some off its energy is transformed into heat. Therefore the signal becomes weaker and weaker as it travels farther and farther. That is why there is a limit on the number of taps, a Buskin support and on the distance between those steps Advantages. He's installation less cabling. These advantages difficult re connection on fault. Isolation a fault are breaking the Bersih Able stops all transmission damaged area reflects signals back that creates nice in both directions. Bust Apology was one of the first apologies used in the design off Ed Leland's Eternity. Lands can use a bus topology, but they're less popular now. Ring topology In this topology, each device has a dedicated point to point connection with only the two immediate neighbors . A signal is passed along the ring in one direction, from device to device until it reaches its destination. Each device in the ring contains a repeater. Many devices receives a signal intended for another device. It's repeated. Region rates the bits and passes them along. Advantages, easy to install and reconfigure. Fault isolation is simplified, and Al Adam rings whenever a problem occurs, indicating the location. These advantages. Traffic is uni directional. A break in the ring can disable the entire network. Drink Apology was prevalent on IBM introduced its local area network token ring. Today. The need for higher speed lands has made this topology less popular. Hybrid apology and network can be hybrid, for example, we can have a main star topology, with each branch connecting several stations in a bus topology. 5. Protocols and Standards: protocols and standards to send or receive information center can't simply send bit streams on expect receiver, toe. Understand there should be some rules on which both sender and receiver agree upon. Protocol is a set off rules and regulations framed to cario the communication effectively and efficiently. These particles are the building blocks off company notebooks. Protocol defines farm it off messages within a layer. Violating protocols makes communication more difficult or impossible. The essential elements off a protocol are syntax, semantics and timing. Syntax. The terms Tin tacks referred to the format of the data. The order in which the data is presented. A simple protocol might expect the 1st 8 bits of the data to be the address of the sender. The 2nd 8 bits off the data to be the address of the receiver and the rest of the stream to be the message itself. Semantics refer to the meaning off each section of bits. Interpreting a particular pattern in the packet and taking some action is nothing but semantics. Timing refers to do characteristics when data should be sent on how far the data should be sent for. Sanders produces data at 100 MBPs, but the receiver can process data only at one MBPs, the transmission will overload the receiver, and some data will be lost standard. There are some standards that have been adopted by vendors and manufacturers for effective communication and interoperability. For example, I Tripoli standards. Some standards must be followed when a new design is to be formulated. For example, eight not 2.3 standards lays down the specifications to later to eternity. So if anyone were to design a software or hardware related to Internet, they would have to follow those specifications then that new design would work with all the pre existing, as well as future Softwares or hardware's off Internet. That I communication standards fall into two categories. De facto standards, meaning by fact, are by convention. These standards have not been approved by an organized body, but have bean adopted as standards through whites produced. De facto standards are often established originally by manufacturers who seek to define the functionality off new product or technology. Did your standards meaning by law or by regulation? These are the standards that have been legislated by an officially recognized body. Standards are dollop through the corporation off standard creation committees, forums and government regulatory agencies. Some standard creation committees are International Organization for Standardization. Iast Pro American National Standards Institute, Enos Eye Institute off electrical and electronics engineers. High Tripoli Layers on Services A computer network is a combination off layers services on protocols, the whole process of communication why and network can be divided into separate layers. Purpose off layering is to reduce the design complexity off networks. The task off sending a message from one point in the world to another can be broken into several sub tasks. Each sub task is performed by a separate layer on each layer has its own hardware and software at the lowest layer, a signal are set off signals he's sent from the source computer to Destination Computer A services a set off operations that a layer provides to its upper layer, or an interface between two layers, with the lower layer being the service provider on the upper layer. Being the service user 6. Types of Network Models: types of network models. Some standard network mortals are needed to enable communication between different kinds of networks effectively and efficiently. The two popular standard network models are always, say difference model on the TCP AP different model. The oil say difference model defines a seven layer network on the TCP, a big difference model represent a four layer network. The always say mortal dominated networking literature before 1990. The protocols related to the oil Cemal are not used anymore, but the model itself is actually quite conventional and still valid. TCP a bit became the dominant commercial architecture because it was used untested extensively on the Internet. The always a difference model was never fully implemented. Unlike toys, a difference model in TCP AP, protocols are widely used, but the mortal itself is not off much use. For the same reason we have to examine both of them in detail. It is stuff to explain some types of communication with TCP AP, such as Bluetooth extra, because TCP AP is protocol dependent to both TCP and I pee. But I always say more. You can explain them as it is protocol independent. Always. I model the international organization for standards are bias for is a multinational body dedicated to a worldwide agreement on international standards. The oil, similarly, is developed by the US role in 1984 as the first step towards international standardisation of the protocols, and it was revised in 1995. The oil say model is called open systems interconnection model because it deals with connecting open systems, that is, the systems that are open for communication with other systems. The purpose of the ways I Morley's to facilitate communication between different machines without making changes to the underlying software and hardware. The oil Somalis composed of seven order layers that AL owe us to think about a networking problem layer wise. And they are application layer presentation, layer session lier transport layer network layer data link clear and physically Here. Here we can see the layers involved when a message is sent from center to receiver. As the message travels from Santa to receiver, it may pass through many intermediate notes. These intermediate notes, usually in more only the 1st 3 layers off the ice. I model because the other four layers are dealt with in the sender and receiver that are passing through the stack from application layer to physical air is called encapsulation, and the rivers process is called big absolution. Organization Off oil say layers. These seven layers can be divided into three groups based on their behavior. Physical data link on network layers can be taught off as network support layers. These layers deal with the physical aspect off moving the data from host to host, such as electrical signals, physical connections, physical addressing, reliability, transport, Exeter session presentation on application layers are the user support layers on these layers. Support interoperability among different software systems in a host computer, Layer four or the transport layer acts as a bridge between user support layers and network support layers. And it also ensures the transmitter data from Netflix. Support players must be in a form the user support layers can use and vice versa. Hosts and submits are the basic elements in computer networks. Submit is in olden lawyer layers. 12 and three courts are in olden upper layers 456 and seven. We can say that the upper layers are almost always implemented in software. On the lower layers are a combination of both software and hardware except for the physical layer, which is mostly hardware. An electromagnetic signal at physical layer transmitted to the receiving device. At the receiving machine, the signal gets passed to layer one and is transformed back into digital form. Then the distal messages under a player by layer, with each layer receiving on removing the headers from physical to application layer. Finally, by the time it reaches the application layer, the messages converted back to the readable form. Let's explore each layer in detail. 7. User support layers in OSI model: application earlier application layer is the top. Most layer are the seventh player in oil say model. The application layer is their network applications on their application layer protocols reside. This is the layer their user, whether human or software actually in tracks. Applications that has networking capacity to connect with people on other networks are on the same network. Application earlier offers user interfaces on support services. Suggests natural cultural terminal remote file handling. Elektronik May database services, Extra network or Chiltern? No, it's a softer version off a physical terminal, the Tello's a user to log on to a remote host. The more file handling services aloes a user toe access and manage files in a remote host from the local computer presentation layer. The next layer is the presentation layer, which basically lives on the operating system. We in tracked with application layer that intern sense information to the presentation layer that our translation that encryption and decryption compression decompression all these things happen in the presentation layer. Text data will be translated to ask er Unicord format on the media that I can be translated to Jeb Peg or MP three ex cetera, encryption and compression happens at the center side. Encryption happened for security reasons when we send, since your information like credit card numbers and so on and compression is to compress the message and make it lightweight. Decompression, decryption and translation happens at the receiver side on our exact opposite off compression, encryption and translation session layer. It deals with creating, maintaining and synchronizing sessions among different communicating systems. Sessions offer various services. Della Control is to keep track off whose turn it is to transmit and whether it is half duplex or full duplex. Synchronization is too low to add. Checkpoints are synchronization points to a stream of data to allo them to pick up from where they left off. In the event off crash and subsequent recovery, the center is sending 100 MB video. It is advisable to insert checkpoints after every fire. Be to ensure that each fi MBI unit is received and acknowledged independently. In this case, if a crash happens during the transmission at 63 m, be the only data that need to be re sent after the system record is 61 to 63. Transport layer transport layer is the bridge between user support lay years on network support. Layers on provide the falling services such as and two in delivery segmentation, reassembly, connection control, flow control on other control and two in delivery off messages. Transport layer ensures so students nation delivery off a message from a specific sander process on one computer to unspecific receiver. Process on the other had off. Transport layer contains the information about the port. Address off the specific process segmentation and reassembly. Transport layer Dwight's a message into transmittable segments with sequence numbers and reassemble them correctly at the destination Connection Control the transport layer supports both connection less on connection oriented services. A connection service streets Each segment as an independent packet on delivers them to the destination independently. A connection oriented service ensures having the connection with destination before delivering the package. Flo Control. The transport layer manages the rate of transmission between two notes to prevent a fast center from transmitting more data and vice versa under control. The transport layer ensures the entire message arrives at the destination transport layer without any damage loss or duplication. It does other correction through retransmission or other deduction. Goats like checks um, transport lee or set up maintain UNT tear down connections for the session layer 8. Network support layers in OSI model: network layer network layer provides the falling services such as rotting off package, Logical addressing on, submit control, trotting off packets and logical addressing natural clear receives segments from the transport layer and wraps Eat segment with I P Header or logical. It does Exeter, which is known as a packet. It decides route with the help of connecting devices called routers or switches, possibly across multiple networks or links, so that packets ultimately reached the final destination. Sub net control. The natural clear controls the operation of the sub net. If to money packets are present in the sub net at the same time, they will get in one others way, forming bottlenecks. Congestion control is also a responsibility of the network layer. Here we have to know that the natural clear gets each packet the correct computer. But the transport layer gets the entire message to the correct process. On that computer data link layer data link clear transforms the physical air into a real able link. In other words, it makes physical layer appear ever free to the natural, clear by masking the real errors so the natural cleared doesn't see them. Data link clear has to sub layers. Logical Link Control, which provides flow control on other control and media access control, provides physical addressing as well as logical topology. Logical apologies Describe how signals act on the network. Data link Layer is responsible for ever free data transmission framing at a detection flow control on physical addressing framing in this layer, backers airplane from network layer become frames on this process is called framing. The data link layer is responsible for moving frames from one heart or node to the next. The data link clear is concerned with local delivery off frames on the same level off the network. The services relabel the receiver confirms correct receipt off each frame by sending back acknowledgement from physical addressing data. Link layer adds header to the frame to define the sender or receiver off the frame. If the frame is intended for a system outside the Sanders Network, the receiver disease address of the device that connects the network to the next one Flo Control Data Link layer imposes airflow control mechanism to a wide vote, overwhelming the receiver when Sandra is sending more than the receiver could process better control. The data Lynn clear can detect and retransmit damaged or lost frames on recognized duplicate frames under control is achieved by adding a trailer at the end of the frame. Access control when two or more devices are connected to the same link, Data link layer protocols that reminds which otherwise has control or the link at any given time. Data link layer mainly deals with switches on bridges in the network. Physical layer in noisy model. It is the layer where literally all the fighting presence. This includes patch cords. Cabling Exeter on this layer defines the type of transmission medium on its interfacing characteristics with the connected devices. Physical air deals with electrical and mechanical specifications, timing interface on transmission medium and it is responsible for transmitting rabbits or a physical communication channel. Most of the networking problems are physical air problems. This layer receives frames from data link layer on converts the frames into orbit. The physical area is responsible for encoding that is including zeros on once into electrical signals, data rate that is duration off a bit, or how long a bit lasts. Synchronisation off bits that is sender and receiver not only must use the same betrayed but also use synchronized clocks line configuration. That is, whether connection of devices to the transmission medium ease point to point or multi point physical topology. That is how dividers are connected. To make a network mesh start drinking Exeter transmission mode. It defines the direction of transmission between two devices. Whether simplex half duplex are full duplex simplex more is a one way communication only one device can send. The other can only receive in the half duplex mode to devices can send and receive, but not at the same time. In full duplex or simply duplex, two devices can send and receive messages at the same time. Some other devices used in this physical layer our network interface controller repeater, either knit hub ex cetera. 9. TCP/IP model: history off DCP AP model First DC Baby was outlined by self and Con in 1974 and later it became a standard in the Internet community by 1989. Initially, the Arpanet used Lizzie telephone lines to link computers in hundreds off universities and government offices. However, due to the addition off new networks such as radio on satellite networks, the existing protocols had trouble inter working with them. Furthermore, applications with divergent requirements were envisioned, ranging from transferring files to real time speech transmission Exeter. So a new and flexible architecture was needed to connect different types of networks seamlessly, and also to ensure the connection is not lost as long as the source and destination machines were functioning. Even if some of the machines are transmission lines in between were suddenly blown away. All these requirements led to a Newark picture and was named as the TCP, a peer of France model, and it is named after its two fundamental protocols, TCP an I P. The initial particles are built on top off connection list technology with packet switching networks, and these initial particles can run across different types of networks. PCP, a peer of France model was dollop a 10 years clear to the ice I model and it was the prevalent model used in both our planet and also on the Internet we used today. The TC paper model was divided into four layers Application layer transport layer network clear on link clear. We can see application Layer off Casey Pape immortal as a combination off application presentation. Concessional yourself or else I model and we can relate. Linklater off easy p a. P as a combination off physical on data link layer Soft voice I'm order application layer off TCP AP Model application layer NTC Pape Immortal holds all the higher level protocols the initial particles are Tell it ftp SMTP Dennis Hastert dp Exeter. No need for session and presentation. Lives was perceived in the TCP AP mortal because session on presentation functions are not very useful to most applications and they can be included in the application late itself. Transport layer off TCP AP the purpose of this transport Leary's very similar toe oyster transport layer but represented with two and two and transport protocols that are responsible for delivery off application layer messages between application endpoints by adding a 16 Report number two the packets and to enter and transport protocols are transmission control protocol. TCP on user data. Graham Protocol, UDP. A new protocol a CTP, or stream control transmission protocol has been added to provide support for new applications such as vice over the Internet, and it combines the best of both worlds. TCP and UDP Network Clear Network. Clear off easy pay peas responsible for moving network clear packets known as data grams independently to the transport layer, and it is also called as enter network or Internet lier. It defines an official packet and particle format called the Internet Protocol R I. P. The Internet Protocol. It is the transmission mechanism used by the TCP AP protocols, but it is an under label on connection list protocol. It provides no error, checking on no guarantee for delivery off messages. Internet protocol transports data in packets called Data Grams and each data. Graham can be transported separately along different routes. On these data, Grams may arrive in auto sequins or be duplicated. Internet protocol doesn't keep track off the route, and it has no facility for reassembly. Off data grams. It is the job off higher layers to reassemble the data Grams the Internet Protocol uses for supporting protocols, and they are address resolution protocol, Air P Rivers Address, Resolution Protocol, R E R P, Internet Control Message Protocol, ICMP and Internet Group message protocol I GMP. We can discuss about these particles separately in the next videos link. Clear Link Layer is the lowest layer in the TCP AP model, and it describes what the links must do to meet the needs off connection lists. Internet layer It is not really a layer, but rather it is an interface between hosts on transmission links. Linklater converts Packer Tindouf frames and transmits them by the time a frame Rijs the destination. That frame contains a physical address, which is used to identify the destination. Internet or physical address is off 48 bits, and it is built into a network interface card off the network dividers 10. Addressing in computer Networks: addressing to deliver anything from a source to a destination. We need different addresses at different stages off the transit. Suppose to deliver a. Both represent to your friend in the Newark city. We need to provide country name State City on your friends. Local address. We don't all of them. Your gift can't reach your friend. Same goes here in the computer networks In order to deliver some data to a destination, we need a unique Attar's at each stage off the network. Three levels of fat asses are used in the Internet employing the TC paper protocols, and they are physical or this logical it does on the poor. Doctors, as we can see here, each other sees related toe unspecific clear in the TCP AP architecture physical address. The physical address is also called as the Link a does or a Mac address, and it is the address off a node or a host in the network. Every networking device in the world comes with a uniquely burn Mac address, which allows the devices to connect the network. The physical are McAdoo's is the lowest level off address on this address will be used in frames off the link layer to find the physical address off the destination device. The size and format off this physical of this may vary depending on the type of the network . For example, even accuse us a six bite physical address and local talk, however, has a one by dynamic address. The physical or this cannot be changed, and it is a hacks, a dismal others that looks like this logical. Are I peer? Does Physical addresses are not sufficient in the Internet, Brooke, because different networks can have different at this format, so toe identify each host uniquely. A universal addressing system was needed irrespective of the underlying physical network. A logical odysseys usedto identify a public network or public. I pee on the Internet uniquely. Currently it is a 32 bit others. It is so unique that no to publicly are just host on the Internet can have the same i p address, and it looks like this bo tortoises. That I revel at the destination host is not the final task. These days, computers can run multiple applications at the same time, the final object to off network communication is to transmit a message from an application running on a sender machine to an application running on a receiver machine on the network . So we need a separate advising method to identify the applications running on a computer uniquely and that unique others assigned toe. Each process or application is called the port Orders Supporters is off 16 bits in length. Generally, porter dozes off. Normal applications can be in the range off 10 to 4 to 65535 on the port. Numbers 0 to 10 to three are reserved for common on vellum protocols and services like history, DP, ftp, DNS, etcetera. For example, The port of the surface to TP process running on any host is 80 and that cannot be used by any other application our process. 11. Introduction to Physical Layer: physically, it is the lowest layer and Internet model. Any directly interacts with the transmission media. This layer physically carries information from one note to the next node in the network physically performs many complex tasks and important US keys to provide services to its up earlier that is battling earlier physically or creates a signal the stream of bids coming from data link layer and sense that signal true transmission Medium. Now let's look into physical air concepts multiplexing modulation on transmission medium multiplexing. We need a medium wide or wireless to send or receive signals between two notes in the network. Generally, we transferred several signals through a single while is much more convenient to use a single wire to carry several signals than to use a separate wire for every signal. For example, we receive hundreds of TV channels on just a single Why we can't imagine hundreds of wires connected to our television, so transmission off saddle signals or a single transmission medium is called multiplexing. Multiplexing was first used in telegraphy in the 18 seventies. Multiplexing divides the capacity of the medium into several logical channels. Each logical channel can carry different message signal and de multiplexing is a process that extract the original signals at the receiver, and there are three primary multiplexing techniques. Frequency division multiplexing have diem Vaillant division multiplexing WDM on time division multiplexing T dia Abdi um on WDM are designed for analog signals. Tedium is designed for digital signals. Before getting into these multiplexing techniques, we first need to know about bandwidth on modulation bandwidth, you know, to transmit a multiplex of signal to a wire, it must have the capacity to carry that signal. The capacity of a wire or media to carry information is called bandwidth, and the total capacity may be divided into channels to accommodate 80 minutes a signal present in the multiplex. It signals the more bang with a white has the mood that I can transmit. Bandwidth is measured in two different ways in cycles per second or heads for a loved ways on bits per second bps for this televises modulator on de modulator, the range off audible frequencies for humans is only in between 20 hits to 20 killer head. Low frequency signals cannot travel longer distances without a large antenna, which is a big problem in the real world. If we send any to signals with the same frequency they get mixed up, and it will be impossible to tune to any one of the signals while receiving. So radio stations must broadcast them at different frequencies, and each radio station must be given its own frequency Band modulation console. Both these problems adding a carrier or a periodic play form to the original signal is called modulation, which makes it different from other signals, and it is done by a modulator. The reverse process off extracting original signal from modulated Single is called the modulation, and it is done by a de modulator. 12. Multiplexing: frequency division multiplexing you have. Diem is an analog technique that combines analog signals with this technique can divide the available bandwidth off the transmission medium into independent frequency channels on shared those channels. Among the signals to be transmitted through the medium, each orginal signal is modulated with a modulator and converted into different frequency bands, using different techniques like amplitude modulation, frequency modulation, phase modulation, single side band modulation and also using different carrier frequencies. These techniques can be achieved by altering the amplitude frequency or phase of the carrier signal, which is called amplitude frequency, or phase modulation. Respecting the modulated signals are then combined into a single composite signal, which is passed into a transmission medium to transmit all the signals at the time. For example, a cable of man with one mega heads made past 1000 signals off each one killer heads insides . In this case, the cable is divided in 2000 sub channels. All the sub channels in a cable are separated by a God ban that prevents signals from old lapping. The oppose it process happens at the receiver side, broadcasting television signals. He's one of the most common applications for medium have Diem is also used in AM and FM radio broadcasting Very intrusion multiplexing. The basic idea of W um is to combine on transmit my tipple light signals to one single light beam with the multiplex er on to extract those individual light signals from the combined signal with a D. Multiplex. Sir, we already know that a prison can easily combine on split light signals based on the angle of incidence on the frequency. Using this prison kind of technique, we can make a multiplex ER to combine several light signals into one signal on a D multiplex er to split a single light signal into multiple signals. WDM is designed to use fiber optic cables because they have very high data transmission rates than that off metallic cables. WDM has become very popular due to its battle with the bandage off. A typical fiber optic cable is their own 25,000 *** heads. So theoretically, the resume for 2500 10 Gbps channels WD, um, is conceptually very similar to Abdi Um, but it involves light signals instead of electrical signals. Here in Dublin, Diem, we're combining different light signals based on their Waveland are color on the frequencies are very high compared to the idea. Delirium is also an analog multiplexing techniques. One of the common applications of WDM is synchronous optical and truck are sewn it a new method in WDM called dance WD or dwt. Um, it is even greater efficiency by spacing channels closer in the fiber optic cable time division multiplexing. Our media tedium is a distant technique in which the time is shared between the signals. Instead of sharing a portion of bandwidth off the transmission medium, its signal occupies a portion of time in the transmission medium or link. Here in tedium, the signals 123 and four going the link sequence really, rather than simultaneously. But whereas in F D M and W D. Um, all the signals go simultaneously in the lane. Tedium is a pistol multiplexing. Pickney, where distal that are from different sources are transmitted through a time should link. However, this doesn't mean the source cannot produce analog. Better analog data can be sampled and change it to digital letter. Then multiplexes using tedium. It comported that a stream is formed with bits coming from all the sources, which is called a frame. Each frame contains time slots. Each slot corresponds to a particular Selves to l O sequin Shal transmission off each individual service beds on form a frame. Some kind of switch like mechanism is used in the media. The switch gets open in front off a particular connection than the duo's gets a chance to place the data onto the link after taking data from and sources, that is, after making one frame against which starts from four SOS to make another frame. This process continues until all sources stopped transmitting a bit to differentiate each frame. A synchronization bit is added at the beginning, off each frame. Alternatively, one and zero, it is called frame synchronization. An individual source data from all frames passes through an intended channel. Each serves can have different data rates, so to synchronize eat soups with the other sources. It adds additional data bits called big patty or post stuffing. Here, one character from each source forms a frame, but sometimes slots have no data. For example, in 2nd 3rd and fourth frames, we can see no data because all the sources may not send bits at the same time at the same rate on at the same land. There is a possibility for vestige of banquet in synchronous stadium. To overcome this problem, we used a synchronous or statistical tedium with the time slots are allocated dynamically on demand. The multiplex of checks each input line in drowned robin fashion on allocated slot. The line has data to send. Otherwise it skips the line and checks the next line in STD um, multiplex er sense bits as synchronously without fixing starts. This makes receiver complex as it needs to know the source of the data arrived. So we add source address to each look. This may increase overhead, but there are some schemes to minimize this overhead with related addressing where the address land is reduced using module automatic. 13. Transmission Media: transmission media. The transmission media are directly controlled by the fiscally on are usually located below fiscally. Anything that carry information from one place to another can be called as a transmission media. Usually the transmission medium can be a metallic able and free space or a fiber optic cable. Over the years, better metallic media have been invented, like to stay on co axial cables. Optical fibre technology increased the data transmission rate incredibly, and three space, like a black hair on water, was used more efficiently as transmission medium with some new technologies. So the transmission media can be classified broadly into two categories. Guided on unrated guided media includes We stood paid cable quite Jill Cable and fiber optic ing UNDATED Medium uses three space for guided media. The medium's more important to get remind the limitations of plants. Mission for unjaded media. The bandwidth off the signal produced by transmission antenna is more important. Raided media here The signals are transmitted to a solid medium such as copper, twisted pair cable, quite steel, cable or optical fiber. Signal. Telling along any of these media is director by the physical limits off the media, twisted paid on Greg's Elk Able use metallic conductors to transport data in the form off electric signals. Fiber optic cables transport signals in the form of flight. Now we will look into each one of them separately. Mr Big Cable Twisted Pair Cable is a type of lighting in which two conductors with their own plastic insulation are twisted together to improve the electromagnetic compatibility. It was invented by Alexander Graham Bell Compact two CV conductor or uninterested balanced Bayer. A twisted pair reduces electromagnetic radiation or crosstalk, between neighbouring base and the all symbols rejection of factional electromagnetic interference. The interference on the crosstalk can affect both the wives and create unwanted signals. The two white our barrel. The distribution of unwanted signals is not the same in both ways because sometimes one leg is needed to the noise on the other. Maybe Father unequal distribution of noise in the wise affect the original sin. Like the stevia wise balance is maintained, for example, for one first one ladies nearer to the noise and the other is father for the next twist, the rivers happens. This debate and shoes that both ways are equally affected by noise are crossed up, so that issue that calculate the difference between the two receives no unwanted signals. The unwanted signals are mostly cancelled, so we can say the performance of transmission increases the number of tourists per unit. Off land increases crags Ilkin like twisted pair cable Quiet People has an interconnector, which is held in place by either regularly spaced insulating rings. For a solid electric material, which is in turn enclosed in an outer, conduct the altar metallic, wrapping those both as a shield against noise but also a second conductor. This outer conductor is also enclosed in an insulating sheep. On the whole, Caro is protected by a plastic all Gregg's table in carry signals off higher frequency and has higher bandwidth than the twisted pair cable you do. It's a shielding question. Cables are much less susceptible to interference are crossed than the twisted pair cables. Outer collector is grounded on interconnector in shielded from inter feelings, which reduces the cost. Cracknell cable connectors to connect quietly cable. To divide us, we need to exile connectors. The most common type of connector used today ease be insecure. Three public plates of these connectors are the BNC connector, the BNC connector the BNC 10 minute. The BNC connector is used to collect the end of the cable to a device such as a TV set. The being city connector is used to branch out The connection to computer are otherwise. The BNC Terminator is used at the end of the cable to prevent the reflection on signal performance. Although gradual, cable has a much higher bandwidth, the signal weekends rapidly and requires the frequent use off peters. The bigger the diameter off inner and outer conductors, the better the performance of the cable. Quite ill cables are generally used in cable TV sets, long distance telephone transmission, local area. 14. Fiber optic cables: fiber optic cable. The fiber optic cable. The thin, flexible transmission medium made of glass or ultra pure fused silica or plastic to transmit signals in the form off light. There's a cylindrical shape and consists of three concentric sections. The cold, the cladding on the jacket. The core consists off very teams transfer fiver made of glass or plastic. The cladding is a glass or plastic coating that has optical properties different from that off the core. The jacket and circles. A bundle of clouded fibers to understand fiber optic cables. First, we need to explore the nature off light. Let's take a dancer medium on a less dense medium. Introduce a light ray into the denser media. Then it travels in a straight line as long as it is moving through a uniformity. With the ray passes into the dancer medium, the light rate changes it's direction or simply the flips. The angle off instance at which the rate travels along. The interface off two channels is called critical, and if the angle off instances less than the critical angle, the rate reflects our moves closer to the surface with the angle of incidence is equal to the critical angle. The light travels along the interface if it is greater than the critical and Ray reflects and travels again In the dancer substance, which is called total internal reflection, the critical angle changes from substance to substance. Optical fiber uses reflection to carry light to channel a glass or plastic basilica. Court is their only by the cladding off less dense glass or plastic. The difference in density off the two materials must be such that being flight moving through the core is reflected off the cladding and should be refracted into it propagation modes. Currently, there are two moats for propagating light along optical channels. Multi mood on single mode. The multi more propagation can be implemented in two ways. Step index graded index Multi month cyber means multiple beings from a light shows passed through the core in different parts. How these race move within the cable depends on the structure of the coal in step in next fiber, the density off the core is constant. From the center to the edge is the rain moves through this constant density in a strike line until it reaches the interface and suddenly changes. It's direction due to a lower density, so stepping next to the first to the suddenness off. This change, regretted in next table, is the one with varying densities in the court. The court is built in such a way that it has different ministries at different points in a court. The density is highest at the center of the cool on decreases gradually as it moves to the edges. Here we can see the impact of this variable density on the propagation off like bees. Single more propagation. It use a step in next technology on a highly focused light source that limits raised to a small range of angles all close to the horizontal. A single malt cyber itself is manufactured with a much smaller diameter on with substantially lower density than that off multi moved fiber. The densities decreased to make the critical Langley almost talent to the coal to make the propagation of the being nearly horizontal. In this case, angle of incidence off different beans is almost identical on the dealers are negligible. All the beans arrive at the destination together. Fiber sizes. Optical fibres are defined by the ratio of the diameter of the court to the damage off their cladding, both expressed in micrometers fiber optic cable. Connected. There are three types off important characters for fiber optic cables. A C counter S t connector, Anti RJ. Can it? The S E Can occur is used for cable TV. It uses push a full locking system. The straight tip connector is used for connecting cable to networking dividers. It uses a bayonet locking system and is more reliable than S E character MDR Jay Z character that is the same size as RJ 45 Ethernet cables. It is also used as a connecting cable to networking devices applications. Fiber optic cable is often found in backbone networks because it's wideband with these cost effective today with wavelength division multiplexing, we can transfer data at a rate off 1600 Gbps Advantages. SOS Optical Cyber Higher Bandit Lightweight Last signal intonation Immunity to electromagnetic interference for assistance to Karajan materials. Greater immunity to tapping on. It needs fewer repeaters. Come back to the other transmission media. These advantages off optical fiber installation and maintenance requires expedites uni directional light propagation. The cable on the interfaces are relatively more expensive than those off other lighter media