COMMON DEVICES USED IN COMPUTER NETWORKS• Computer network is a group of two or more computers

that connect with each other to share a resource. Sharing of devices and resources is the purpose of computer network. You can share printers, fax machines, scanners, network connection, local drives, copiers and other resources.

• In computer network technology, there are several types of networks that range from simple to complex level. In order to connect computers with each other or to the existing network or, the required devices and rules (protocols) must be observed. Following is partial list of devices commonly used in those networks

HUB• Hub is a device that splits a network connection into

multiple computers. It is like a distribution center. When a computer request information from a network or a specific computer, it sends the request to the hub through a cable. The hub will receive the request and transmit it to the entire network. Each computer in the network should then figure out whether the broadcast data is for them or not.

SWITCH

Switch is a telecommunication device grouped as one of computer network components. Switch is like a Hub but built in with advanced features. It uses physical device (MAC) addresses in each incoming messages so that it can deliver the message to the right destination or port.

Unlike a Hub, switches don’t broadcast the received messages to the entire network, rather before sending, it checks to which system or port the message needs to be sent. In other words a switch connects the source and destination directly which increases the speed of the network.

Router A Router functions to forward packets between separate networks. A Router maintains a

routing table. The routing table contains IP addresses of other networks routers. In a static router the routing table is configured manually, while a dynamic router can communicate with other routers and configure the routing table according to information it receives from other routers

When receiving a data packet, a router examines the packet destination IP address and forwards it to its destination by looking at the routing table. The Router determines the best path to deliver a packet based on the routing algorithm it uses, usually the path will be the shortest and the most reliable.

Bridge A network bridge connects and filters traffic between two network segments at the datalink

layer (layer 2) of the OSI Model to form a single network. This breaks the network's collision domain but maintains a unified broadcast domain. Network segmentation breaks down a large, congested network into an aggregation of smaller, more efficient networks.

Bridges come in three basic types: Local bridges: Directly connect LANs Remote bridges: Can be used to create a wide area network (WAN) link between

LANs. Remote bridges, where the connecting link is slower than the end networks, largely have been replaced with routers.

Wireless bridges: Can be used to join LANs or connect remote devices to LANs

Gateway In a communications network, a Gateway serves as a network node equipped for interfacing

with another network that uses different protocols and may contain devices such as protocol translators, impedance matching devices, rate converters, fault isolators, or signal translators as necessary to provide system interoperability through the establishment of mutually acceptable administrative procedures between both networks.

Firewall In computing, a firewall is a network security system that controls the incoming and

outgoing network traffic based on applied rule set. A firewall establishes a barrier between a trusted, secure internal network and another network (e.g., the Internet) that is assumed not to be secure and trusted. Firewalls exist both as a software solution and as a hardware appliance. Many hardware-based firewalls also offer other functionality to the internal network they protect, such as acting as a DHCP server for that network.

Wireless Access Point(AP)

Access point in a wireless Lan, (Wifi) functions like a hub or a switch in wired network. It connects computers or devices together to create a wireless network. Most wireless access points also function as a network bridge that connects the Wi-Fi network to a wired network such as Ethernet. An access point has an interface to a broadband modem or a router that is used when the Wi-Fi network connects to the Internet. Some access points come as a multi-function device that incorporates the functions of switch, bridge, router, or broadband modem. You may have heard about wireless router which is an access point that has a built-in router

Network ComponentsDiagram