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In this video, we will be covering the different types of network devices which are present in computer network. Hardware devices used to connect computers, printers, fax machines, and many other electronic devices to a network are referred to as network devices. Network devices are classified into intra-network and inter-network. Data transfer is fast when network devices are used. Data is transferred securely over the same or different networks. Data is transferred in a correct manner over the same or different networks.&nbsp; Mostly used network devices in networking are: 1) Repeater: The repeater is used at the physical layer. Its task is to regenerate the signal over the same network before the signal becomes too weak. Repeaters never amplify the signal. When the signal is weak, repeaters bit by bit copy the signal and regenerate it at the original strength.&nbsp; 2) Hub: Hub is a multiport repeater. Multiple wires coming from diverse branches are connected using a hub, for example, in star topology hub is used as a connector that connects different machines.&nbsp; 3) Bridge: Bridge device is used at the data link layer. The bridge is exactly like a repeater, with extra functionality of content filtering by evaluating MAC addresses of source and destination. Interconnects two LANs working on the same protocol. 4) Switch: Switch plays a more intelligent role than hubs. The switch is a multiport bridge with a buffer and a design that increases its performance and efficiency. Switch checks the error before forwarding data, which makes it effective as it never forwards the packets which have errors and only forwards packets that are good and send them only to the correct port.&nbsp; 5) Router: The router device is used at Network Layer. A router device is similar to switch that based on IP addresses routes their data packets. The router splits broadcast domains of hosts connected through it.&nbsp; 6) Gateway: Gateway, is a track or gate to connect two different networks together. Data is taken from one system, interpret, and send to another system. Gateways are known as protocol converters and can operate at any network layer. 7) Access Point: Access point (AP) can technically involve either a wired or wireless connection. It commonly means a wireless device. An AP works at the second layer of the OSI model i.e. the Data Link layer.&nbsp;Network devices: <a href="https://www.geeksforgeeks.org/network-devices-hub-repeater-bridge-switch-router-gateways/">https://www.geeksforgeeks.org/network-devices-hub-repeater-bridge-switch-router-gateways/</a>

Types of Network Devices in Computer Network

In this video, we will be discussing what&nbsp;is Datagram &amp; Virtual Circuit and also what is the difference between datagram &amp; virtual circuits. What is Packet Switching? Packet switching is a technique in which data is transferred in the form of packets to a network. Files are transferred efficiently and fast over the network and transmission delay is minimized. Data is fragmented into tiny pieces of different lengths, called Packets. At the destination, all these tiny pieces (packets) are reassembled, belonging to the same file. The packet contains control information and payload. Resources are not reserved Pre-setup is not required.&nbsp; Packet Switching is known as Store and Forward technique because when packets are switched and when a packet is forwarded each hop first stores that packet and then forward.&nbsp; This method is useful because packets may get rejected at any hop because of some reason.&nbsp; More than one path is possible between a pair of sources and destinations.&nbsp; Datagram: It is a connectionless service. The packet can use any available path to transfer data. Routing of each packet via a network is done on its own. Resources are not reserved as there is no specific channel. All destination information is stored inside the packet header. Intermediate nodes assess the packet’s header and select an appropriate link to a different node closer to the destination. Easy and cost-effective implementation. The receiver receives out-of-order data packets.&nbsp; Virtual circuit switching is a methodology to build a path between the source and the ultimate destination through which all packets will transmit. Before data transmission starts, the source and destination must approve the virtual circuit path. To make a decision, intermediate nodes which are between two places add routing entries to their routing database.&nbsp; Extra parameters, like maximum packet size, are exchanged between source and destination during call setup. Once the information is transferred successfully, Virtual Circuit is terminated.Difference between Datagram &amp; virtual circuit: <a href="https://www.geeksforgeeks.org/difference-between-datagram-switching-virtual-circuit/">https://www.geeksforgeeks.org/difference-between-datagram-switching-virtual-circuit/</a>

Difference between Datagram and Virtual Circuit

In this video, we will be discussing the difference between Manchester Encoding&nbsp;and Differential Manchester Encoding. What is Manchester Encoding? Manchester encoding is used for synchronizing clock. It is used by physical layer of OSI, so that data and clock of synchronous bit stream is encoded. Since length of each data bit is described by default, it is different from other digital encoding techniques. It came into existence before differential manchester encoding&nbsp; Manchester encoding main advantage is signal synchronization. DC component of signal carries no information. This makes it possible that standards that usually do not carry power can transmit this information. Signal rate is the drawback of Manchester Encoding. The reason is that there is always one transition at the middle of the bit and maybe one transition at the end of each bit.&nbsp; What is Differential Manchester Encoding? Differential Manchester Encoding combines clock and data signals together to form a single synchronizing data stream of two levels. Transition always happens at middle of the bit, but at the beginning of the bit determination of bit values is done. There is transition if next bit is zero and no transition if the next bit is 1.&nbsp; Manchester encoding improvement is done in differential Manchester encoding.&nbsp; If high and low signal levels have the same magnitude with opposite polarity, the average voltage around each unconditional transition is 0. 0 DC bias reduces necessary transmitting power, minimizes the amount of electromagnetic noise produced by the transmission line, and eases the use of isolating transformers.&nbsp;

Difference between Manchester & Differential Manchester Encoding in Computer Networks

In this video, we will understand Manchester Encoding in Computer networks in detail. Encoding is used to provide data security and to increase transmission speed of data. In data communication different encoding techniques are used. Synchronization problem is solved using bi-phase encoding. Signal state transition happens at the middle of the bit. It does not returns to zero.&nbsp; Two types of bi-phase encoding techniques are used 1) Manchester encoding&nbsp; 2) Differential Manchester encoding.&nbsp; Manchester encoding is used for synchronizing clock, used by physical layer of Open System Interconnection [OSI], so that data and clock of synchronous bit stream is encoded. Digital encoding example is Manchester Encoding. Since length of each data bit is described by default, it is different from other digital encoding techniques. Direction of transition decides the bit state. Bit status is represented differently by different systems, most systems use 1 bit for low to high transitions and 0 bit for high to low transitions.&nbsp; Watch complete video to understand Manchester encoding further in detail Manchester encoding in Computer Network: <a href="https://www.geeksforgeeks.org/manchester-encoding-in-computer-network/">https://www.geeksforgeeks.org/manchester-encoding-in-computer-network/</a>

Manchester Encoding with Example | Computer Networks

In this video, we will be discussing the Physical layer of OSI reference model in detail.&nbsp; The lowermost layer in Open System Interconnection (OSI) Model is Physical Layer. Physical Layer is the electrical as well as physical description of system. It includes several network components such as power plugs, connectors, receivers, cable types, etc.&nbsp; Physical Layer transmits data bits from one computer to another computer. Physical Layer defines encoding types i.e how the 0’s and 1’s are converted into signal. Physical Layer is allows communication of the unstructured raw data streams over a physical medium. OSI model’s physical layer interconnect with signaling and hardware mechanism. Physical layer is responsible for physical connectivity of two different devices (computers).&nbsp; The services are provided by Physical layer to Data-link layer &amp; in turn Data-link layer gives frames to physical layer. Physical layer converts them to electrical pulses, which represent binary data. Binary data is then transmitted over guided or unguided transmission media. Functions performed by Physical layer: 1) Representation of Bits 2) Data Rate 3) Synchronization 4) Interface 5) Line Configuration 6) Transmission Modes The Physical Layer is concerned with transmitting raw bits over a communication channel. The issue has to do with making sure that when one side sends 1 bit, it is received by the other side as 1 bit and not as 0 bit. The design issues here largely deal with mechanical, electrical &amp; timing interfaces, and the physical transmission medium lies below the physical layer. Physical layer in OSI model: <a href="https://www.geeksforgeeks.org/physical-layer-in-osi-model/">https://www.geeksforgeeks.org/physical-layer-in-osi-model/</a>

Physical Layer in OSI Model | Computer Network

In this video, we have covered TCP/IP Model in detail.&nbsp; But to begin with, let us first see what is TCP/IP? TCP/IP stands for Transmission Control Protocol/Internet Protocol. It is named after two main protocols that are used in the model, TCP and IP. Designed to describe functions of a communication system by dividing communication procedures into smaller and simpler components. TCP/IP is based on standard protocols.&nbsp; It is a set of rules and methods that are used to interconnect network devices on the Internet.&nbsp; Layers of TCP/IP Model: Application Layer: The layer at the top of the TCP/IP model is the application layer. One application-layer protocol communicates with another application-layer protocol by transferring the information to the transport layer. Transport Layer: Provides flow control, error control, reliability, and data correction when data is sent over the network. User Datagram Protocol(UDP) and Transmission control protocol(TCP) are the two protocols used at this layer. Internet/Network: The Internet layer also called as Network layer, is the third layer of TCP/IP Model. This layer is responsible for sending packets from any network, and they arrive at the destination irrespective of the route they take. Network Access: Layer bottom layer of TCP/IP Model. The physical Layer and Data link layer in the OSI Model are combined together and they are named Network Access Layer in TCP/IP Model. Responsible for the transmission of information between two devices over the same network. Benefits of TCP/IP layer: 1) It is an industry-standard illustration that can be placed in organizing problems. 2) Allows interoperability by permitting cross-platform communications between different networks. 3) It is an open agreement suite. It isn’t claimed by anyone specific and can be utilized by any individual or organization. Challenges of TCP/IP layer: 1) Bluetooth connection cannot be portrayed using TCP/IP Model. 2) It does not evidently separate the services concepts, interfacing, and protocols. So, it isn’t proper to depict unused advances in new networks. 3) Difficult to differentiate between physical and data link layers, which actually have distinguishing features. 4) Information interface layer is responsible for the transmission of outlines.&nbsp; 5) Physical layer is responsible for the physical characteristics of the transmission. 6) Delivery of packets is not guaranteed by the transport layer in this model. TCP/IP Model in Computer Networking: <a href="https://www.geeksforgeeks.org/tcp-ip-model/">https://www.geeksforgeeks.org/tcp-ip-model/</a>

What is TCP/IP Model and How it Works? | Computer Network

In this video, we will see what is Transmission media &amp; what are the types of transmission mediums. Transmission media is a medium through which data signals travel or are transmitted from sender to receiver.Transmission mediums are mainly of two types, which are as follows: - Guided media &amp; Unguided media1) Guided Media: It means sending data using wires/cables. Guided media uses a guide, shield, cladding, insulation to bind signal that is contained within an enclosed physical medium. Examples: twisted pair, coaxial cable, &amp; optical fiber.In a Twisted pair cable, two copper wires are “twisted” together in a spiral pattern. It carries both analog and digital signals and the data transfer rate is in Mbps. A maximum transmission distance of 1km can be achieved for data rates up to 1 Mb/s. The data rate is dependent on the thickness and length of the wire.Coaxial Cable contains a copper core surrounded by insulating material and a plated outer conductor. There is an outer plastic covering containing an insulation layer made of Teflon or PVC and two parallel conductors each having a separate insulated protection cover.Fiber optics cable has no electrical signal, it’s medium consists of hair-width strand of silicon or glass, and signal consists of pulses of light. It has cylindrical shape and consists of three concentric sections, which are Core, Cladding, and Jacket.2) Unguided Media: In unguided media, data transfer is done without wires using electromagnetic waves. e.g.: wireless transmission. Wireless transmission systems do not make use of physical conductor, or guide, to bind signal. Energy travels through the air rather than copper or glass. Such systems employ electromagnetic energy in the form of radio or light waves that are transmitted and received across space, and are referred to as airwave systems.In an unguided medium, data transmission takes place using Radiowave, Microwave, and Infrared waves.Types of Transmission Media:<a href=" https://www.geeksforgeeks.org/types-transmission-media/"> https://www.geeksforgeeks.org/types-transmission-media/</a>

Transmission Media in Computer Networks

The Caesar Cipher technique is one of the earliest and simplest method of encryption technique. It’s simply a type of substitution cipher, i.e., each letter of a given text is replaced by a letter some fixed number of positions down the alphabet.&nbsp;For example with a shift of 1, A would be replaced by B, B would become C, and so on. The method is apparently named after Julius Caesar, who apparently used it to communicate with his officials.&nbsp; Thus to cipher a given text we need an integer value, known as shift which indicates the number of position each letter of the text has been moved down.Caesar Cipher: <a href="https://www.geeksforgeeks.org/caesar-cipher-in-cryptography/">https://www.geeksforgeeks.org/caesar-cipher-in-cryptography/</a>

Caesar Cipher

In this video, we have covered the different types of Networks.1) LAN: Local Area Networks are limited to a small area. LANs are privately owned networks that offer high speed. In a LAN network, all the devices are connected over a common medium so that users can share access to host computers, peripherals, databases, files, and applications. LAN network is used in communication channels that have limited geographical areas such as offices, schools, buildings, or campuses. Hardware &amp; Software can be shared easily. It is low in cost and easy to control and manage. It uses a central hub to store user’s data. LAN are easy to configure as all the required protocols are already available in operating system. But it is limited to small geographical areas and more prone to malware and viruses, also it needs high maintenance LAN needs constant upgradation and its architecture is bit complex.2) WAN: Wide area network is defined as a group of local area network that communicates with each other. It connects various places located in a larger geographical area such as city, state, country, or continents. There is no limitation on the area. It makes use of dedicated transoceanic cabling or satellite uplinks to connect and operate the network. WAN works at the bottom three layers of OSI interconnection model, i.e. Physical layer, data link layer, and network layer. WAN connects many LANs together and uses switching technology by local exchange and long-distance carriers. It has Error-prone links. Inter-exchange carriers are leased lined at a monthly cost that provides wide area network links. WAN increased the efficiency of the network and provide easy communication. It provided a larger network coverage area. In WAN messages are sent faster to everyone on the network. IT infrastructure is centralized in WAN and it has high privacy.3) MAN: Metropolitan Area Network covers large geographic areas such as cities or districts by interconnecting smaller networks within larger geographic areas. The information is shared throughout the network. Government organizations use MAN to connect to citizens and private industries. In MAN, different LANs are connected through a local telephone exchange.&nbsp; MAN protocols are RS-232, X.25, Frame Relay, ATM, ISDN, ADSL. It is more secure than WAN and is wider-ranging than LAN. It is quite cost-effective as it shares common resources. Needs less implementation cost because MAN requires fewer resources compared to WAN. The dual bus used in MAN help transmission of data in both direction simultaneously.Types of Network: <a href="https://www.geeksforgeeks.org/types-of-computer-networks/">https://www.geeksforgeeks.org/types-of-computer-networks/</a>

Types of Networks in Computer Network

Topologies are a geometric representation of the relationship of links and linking of devices with one another. Two or more computers connected to each other using cables form a link, and two or more links collectively form a topology.In computer networks, topologies are mainly categorized into the following types:1) Mesh topology 2) Star topology 3) Bus Topology 4) Ring Topology 5) Tree Topology 6) Hybrid TopologyMesh Topology: In mesh topology each device has a dedicated point-to-point link to every other device. Dedicated connection means that cable carries data only between two devices. If N number of devices are connected with each other in the mesh topology then, ports required by each device is N-1, and total number of ports required in the topology is N*(N-1). Total number of dedicated cables required to connect them is NC2, i.e.N(N-1)/2.Mesh topology is robust and secure. But it is difficult to install and configure the mesh topology and cost is also high as compared to other topologies.Star topology: Each device has a dedicated point-to-point link with a central controller, known as a hub. Devices are not linked to one another directly, so each device needs one link and one port to connect with the central hub. If a device wants to send the data to another device, so it will send it to the controller, then it is the responsibility of the hub to transmit the data to the correct destination. If N number of devices are connected in star topology so the number of cables required is N. Star topology is robust and has easy fault detection and isolation mechanism. But the entire system is dependent on the central controller, i.e. hub and the cost of installation is high.Bus Topology: In a bus topology, one long cable is the backbone to connect all the computers in a network. Computers are connected to bus cables by drop lines &amp; taps. A drop line is a connection running between the device &amp; main cable. It is not bidirectional, and has multipoint connection. It is not robust because the entire dependency is on backbone cable.Ring Topology: Each device has a dedicated point-to-point connection with only two devices on either side of it. The signals are passed along the ring in one direction, from device to device, until it reaches their destination. Signal can be made bidirectional, using two connections between each node. Repeaters are used in ring topology to prevent data loss.This topology is cheap to install and expand and has easy fault isolation mechanism. But it is difficult to troubleshoot the problem in ring topology and it is unidirectional.Tree Topology: Tree topology has a hierarchical stream of data. Secondary hubs are connected with a central hub that has repeaters. Data flow from top to bottom or vice versa, i.e. from a central hub to devices. More devices can be connected to a central hub easily, it allows network isolation and also prioritizes signals from different devices. But the entire dependency of the system on the central hub.Hybrid Topology: This topology is a combination of two or more different topologies to make a resultant topology with advantages of basic topologies instead of having the characteristic of only one specific topology. Hybrid topologies are completely reliable, flexible, scalable, has easy fault detection and troubleshooting, it can handle a large network. But it is complex in design and are expensive in costNetwork Topologies: <a href="https://www.geeksforgeeks.org/types-of-network-topology/">https://www.geeksforgeeks.org/types-of-network-topology/</a>

Network Topology | Computer Networks

This video explains circuit switching and packet switching techniques with examples. And also explain the concepts with their advantages and disadvantages. Switched communication networks are those in which data transferred from source to destination is routed between various intermediate nodes. Switching is the technique by which nodes control or switch data to transmit it between specific points on a network. There are 3 common switching techniques: 1. Circuit Switching 2. Packet Switching 3. Message SwitchingCircuit Switching vs Packet Switching : &nbsp;<a href="https://www.geeksforgeeks.org/difference-between-circuit-switching-and-packet-switching/">https://www.geeksforgeeks.org/difference-between-circuit-switching-and-packet-switching/</a>

Circuit Switching vs Packet Switching | Computer Networks

Routing is a process in which the network layer devices (either router or layer 3 switches) find the optimal path to deliver a packet from one network to another. Basically, there are two different types of routing algorithms: 1) Static routing 2) Dynamic routing This video mainly focused on Routing Protocols and their different types. So the term Routing Protocols are the set of defined rules used by the routers to communicate between source &amp; destination. They do not move the information from the source to a destination, but only update the routing table that contains the information. The Network Layer of the OSI Model is responsible for providing logical addressing, which routers use to select the best path for routing packets.&nbsp;Related articles:&nbsp;<a href="https://www.geeksforgeeks.org/routing-v-s-routed-protocols-in-computer-network/ ">https://www.geeksforgeeks.org/routing-v-s-routed-protocols-in-computer-network/&nbsp;</a><a href="https://www.geeksforgeeks.org/classes-of-routing-protocols/">https://www.geeksforgeeks.org/classes-of-routing-protocols/</a>

Routing Protocols and Its Types

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