User datagram protocol (UDP) is a transport layer protocol. It is a connectionless, unreliable protocol that has no flow-and-error control. UDP uses port numbers to multiply data from the application layer. UDP is a simple protocol, it has less overhead. Suppose a process wants to send a small message, then UDP would require very little interaction between the sender and the receiver as compared to the transmission control protocol (TCP).UDP User Datagram FormatUDP packets user datagram has a fixed size header of 8 bytes.UDP Header − It is an 8-bytes fixed header. The first 8 bytes of a datagram contain ... Read More

Transmission Control Protocol/Internet Protocol (TCP/IP) model is a concise version of the OSI Model. The TCP/IP protocol suite was developed before the OSI model. But the layers in the TCP/IP protocol suite do not exactly match those in the OSI model.TCP/IP ProtocolThe original TCP/IP protocol uses four layers − host-to-network, Internet, Transport, and Application layer.The host-to-network layer is equivalent to the combination of physical and data link layers in the OSI model.The Internet layer in TCP/IP is equivalent to the Network layer of the OSI model. And the Application layer does the job of the Session, Presentation, and Application layers ... Read More

In distance-vector routing (DVR), each router is required to inform the topology changes to its neighboring routers periodically. Historically it is known as the old ARPNET routing algorithm or Bellman-Ford algorithm.How the DVR Protocol WorksIn DVR, each router maintains a routing table. It contains only one entry for each router. It contains two parts − a preferred outgoing line to use for that destination and an estimate of time (delay). Tables are updated by exchanging the information with the neighbor’s nodes.Each router knows the delay in reaching its neighbors (Ex − send echo request).Routers periodically exchange routing tables with each ... Read More

Transmission Control Protocol (TCP) provides a secure and reliable connection between two devices using the 3-way handshake process. TCP uses the full-duplex connection to synchronize (SYN) and acknowledge (ACK) each other on both sides. There are three steps for both establishing and closing a connection. They are − SYN, SYN-ACK, and ACK.3-Way Handshake Connection Establishment ProcessThe following diagram shows how a reliable connection is established using 3-way handshake. It will support communication between a web browser on the client and server sides whenever a user navigates the Internet.Synchronization Sequence Number (SYN) − The client sends the SYN to the serverWhen ... Read More

Circuit SwitchingCircuit Switching is a connection-oriented service. It provides a dedicated path from the sender to the receiver. In-circuit switching, a connection setup is required to send and receive data. It has very little chance of data loss and error due to the dedicated circuit, but a lot of bandwidth is wasted because the same path cannot be used by other senders during a congestion. Circuit switching is completely transparent; the sender and receiver can use any bit rate format or framing method.Advantages of Circuit SwitchingIt uses a fixed bandwidth.A dedicated communication channel increases the quality of communication.Data is transmitted ... Read More

Network devices or networking hardware are the physical devices that are used for establishing connections and facilating interaction between different devices in a computer network. Hub Hubs work in the physical layer of the OSI model. A hub is a device for connecting multiple Ethernet devices and making them act as a single network segment. It has multiple inputs and output ports in which a signal introduced at the input of any port appears at the output of every port except the original incoming port. A hub can be used with both digital and analog data. Hubs do not perform ... Read More

Routing is the process of moving the data across a network from a source to a destination. Routing algorithms are used to decide the route or the output line a packet should be transmitted on. Routing algorithms determine the optimal path to reach a destination.A good routing algorithm should process properties such as correctness, simplicity, robustness, stability, fairness, and optimality.Fixed RoutingFixed routing is used to find a single permanent route for each source-to-destination pair. It determines the routes using a least-cost algorithm and the routes are fixed at least until a change occurs in the network topology.Fixed Routing − ExampleCentral ... Read More

In Computer Networks, Hamming code is used for the set of error-correction codes which may occur when the data is moved from the sender to the receiver. The hamming method corrects the error by finding the state at which the error has occurred.Redundant BitsRedundant bits are extra binary bits that are generated and added to the information-carrying bits of data transfer to ensure that no bits were lost during the data transfer. The redundancy bits are placed at certain calculated positions to eliminate the errors and the distance between the two redundancy bits is called "Hamming Distance".Error Correction Code − ... Read More

Dynamic Host Configuration Protocol (DHCP) is a client/server protocol that automatically provides an Internet Protocol (IP) host with its IP address and other related configuration information such as the subnet mask and default gateway. In DHCP, port number 67 is used for the server and 68 is used for the client.DHCP allows a network administrator to supervise and distribute IP addresses from a central point and automatically sends a new Internet Protocol (IP) address when a computer is plugged into a different place in the network.DHCP is an application layer protocol that provides −Subnet MaskRouter AddressIP AddressDHCP Client-Server Communication DiagramIn ... Read More

MultiplexingMultiplexing is the process of collecting the data from multiple application processes of the sender, enveloping that data with headers and sending them as a whole to the intended receiver.In Multiplexing at the Transport Layer, the data is collected from various application processes. These segments contain the source port number, destination port number, header files, and data.These segments are passed to the Network Layer which adds the source and destination IP address to get the datagram.DemultiplexingDelivering the received segments at the receiver side to the correct app layer processes is called demultiplexing.The destination host receives the IP datagrams; each datagram ... Read More