Found 496 Articles for Computer Engineering

A gateway is a network node that forms a passage between two networks operating with different transmission protocols. The most common type of gateways, the network gateway operates at layer 3, i.e. network layer of the OSI (open systems interconnection) model. However, depending upon the functionality, a gateway can operate at any of the seven layers of OSI model. It acts as the entry – exit point for a network since all traffic that flows across the networks should pass through the gateway. Only the internal traffic between the nodes of a LAN does not pass through the gateway.Features of ... Read More

Routers are networking devices operating at layer 3 or a network layer of the OSI model. They are responsible for receiving, analysing, and forwarding data packets among the connected computer networks. When a data packet arrives, the router inspects the destination address, consults its routing tables to decide the optimal route and then transfers the packet along this route.Features of RoutersA router is a layer 3 or network layer device.It connects different networks together and sends data packets from one network to another.A router can be used both in LANs (Local Area Networks) and WANs (Wide Area Networks).It transfers data ... Read More

Switches are networking devices operating at layer 2 or a data link layer of the OSI model. They connect devices in a network and use packet switching to send, receive or forward data packets or data frames over the network.A switch has many ports, to which computers are plugged in. When a data frame arrives at any port of a network switch, it examines the destination address, performs necessary checks and sends the frame to the corresponding device(s). It supports unicast, multicast as well as broadcast communications.Features of SwitchesA switch operates in the layer 2, i.e. data link layer of ... Read More

Hubs are networking devices operating at a physical layer of the OSI model that are used to connect multiple devices in a network. They are generally used to connect computers in a LAN.A hub has many ports in it. A computer which intends to be connected to the network is plugged in to one of these ports. When a data frame arrives at a port, it is broadcast to every other port, without considering whether it is destined for a particular destination device or not.Features of HubsA hub operates in the physical layer of the OSI model.A hub cannot filter ... Read More

Spanning Tree Protocol (STP) is a communication protocol operating at data link layer the OSI model to prevent bridge loops and the resulting broadcast storms. It creates a loop − free topology for Ethernet networks.Working PrincipleA bridge loop is created when there are more than one paths between two nodes in a given network. When a message is sent, particularly when a broadcast is done, the bridges repeatedly rebroadcast the same message flooding the network. Since a data link layer frame does not have a time-to-live field in the header, the broadcast frame may loop forever, thus swamping the channels.Spanning ... Read More

In data communications, wormhole switching a flow control technique where large data frames or packets are partitioned and then transmitted. When a switching device (a bridge or a switch) receives a data packet, it partitions the packet into small parts called flow control units or flits. The flits are transmitted one by one instead of the whole packet. Also called wormhole flow control, wormhole switching is subtype of flit-buffer flow control methods and is based upon fixed links.Working PrincipleIn this technique, each packet or frame is broken into smaller pieces of data called flits. The header flits contain the destination ... Read More

In data communications, cut-through switching is a method of switching data frame or data packets, where the switching device (bridge or switch) forwards the frames or packets as soon as the destination address is available without waiting for the rest of the data to arrive.Working PrincipleCut-through switching is used in packet switching systems. In packet-switching, the message is divided into a number of units called packets that are individually routed from the source to the destination. There is no need to establish a dedicated circuit for communication, since it is a connectionless network switching technique.In cut − through switching, when ... Read More

A bridge is a network device that connects multiple LANs (local area networks) together to form a larger LAN. The process of aggregating networks is called network bridging. A bridge connects the different components so that they appear as parts of a single network. Bridges operate at the data link layer of the OSI model and hence also referred as Layer 2 switches.The following diagram shows a bridges connecting two LANs −Uses of BridgeBridges connects two or more different LANs that has a similar protocol and provides communication between the devices (nodes) in them.By joining multiple LANs, bridges help in ... Read More

Virtual Local Area Networks or Virtual LANs (VLANs) are a logical group of computers that appear to be on the same LAN irrespective of the configuration of the underlying physical network. Network administrators partition the networks to match the functional requirements of the VLANs so that each VLAN comprise of a subset of ports on a single or multiple switches or bridges. This allows computers and devices in a VLAN to communicate in the simulated environment as if it is a separate LAN.Features of VLANsA VLAN forms sub-network grouping together devices on separate physical LANs.VLAN's help the network manager to ... Read More

Network switching is the process of forwarding data frames or packets from one port to another leading to data transmission from source to destination. Data link layer is the second layer of the Open System Interconnections (OSI) model whose function is to divide the stream of bits from physical layer into data frames and transmit the frames according to switching requirements. Switching in data link layer is done by network devices called bridges.BridgesA data link layer bridge connects multiple LANs (local area networks) together to form a larger LAN. This process of aggregating networks is called network bridging. A bridge ... Read More