An Overview of the Computer Network Devices & Components

A Computer network is comprised of differentthe higher speed and still interact with the 10Mbps
devices to share, transmit, and boost the signal,system.
voice and data. Network devices or componentsSWITCHES: Switch is a intelligence device than
are the physical parts connected to a network.hub. Switch is a layer 2 device. Swith provides the
There is a large number of the network devicessame function as a hub or a bridge but it has the
and are increasing daily. The basic networkadvance functionality of connecting the two
devices are: Individual Computers, Server, Hub,computers together temporarily. Switch contains
Switch, Bridges, Routers, Modems, Printers, DSLthe switch matrix or switch fabric that can
Modems & Routers, Gateways, Networkconnect and disconnect ports. Unlike hubs, switch
Interface Cards, Cabling & Wireless accessonly transmit or forwards the data to the
point. The following is a overview of each ofdestined computer and it does not broadcasts the
these network devices.data to all its ports.
INDIVIDUAL COMPUTERS: The personalMODEMS: Modems are the devices, which are
computer is usually a desktop computer, a workused to translate the digital data into the analog
station or a laptop. The personal computers areformat and vice versa. It performs the two main
most widely used in any organization or forfunctions. Modulation and demodulation. A
personal use. The individual computers are themodulated data can travel across the conventional
most common types of the microcomputers.telephone lines. The modem modulates the signals
SERVER: A server is a computer on a network,at the sending end and demodulates at the
which process request and is used to share thereceiving end. Modems are required for different
data and resources among the other computerstypes of the access methods such ISDN, DSL
in a network. A server stores all the necessaryand 56K data modem. Modem can be the internal
information and provides the different servicesdevices that plug into the expansion slots in a
like, workstation computer's logon access, internetsystem or can be external devices that plug into
sharing, print sharing, disk space sharing etc. Therethe serial or USB ports. In Laptops, PCMCIA cards
are different types of servers e.g File and printare used for this purpose and many new laptops
server, database server, proxy server, Faxhaving the built in integrated modems. The
server, backup server etc. A database serverspecialized devices are designed for use in the
stores all the data and software, which maysystems such as handheld computers. In ISPs
related to the certain database and it allows otherwhere the large scaled modems are required,
network devices to access and process therack-mounted modems are used.
database queries. A file server is used to storeROUTERS: Routers route the data between two
the data of any user on the network and a printlogically and physically different networks. A
server manages one or more printers in aRouter has the capability to determine the
network. Similarly a network server is a serverdestination address for the data and hence
that manages the network traffic.provides the best way for the data to continue
NETWORK INTERFACE CARD: Network interfaceits journey. Router gets this capability through its
cards are attached with the computer or othersoftware called routing software. Unlike Switches
network devices and are used to provide theand Bridges, which use hardware configured MAC
connectivity between the two computers. Eachaddress to determine the destination of the data,
network card is specifically designed for therouter uses logical network address such as IP
different types of the network like Ethernet,address to make the decision in determining the
FDDI, Token Ring and Wireless Networks. Thedestination of the data.
Network card operates on the first and secondGATEWAY: A gateway performs the function of
layers of the OSI models i.e Physical layer andtranslating the data from one format to another
datalink layer specifications. NIC basically definesformat without changing the data itself. A
the physical connection methods and the controlgateway can be a device, system, software. A
signals that provides the timings of the datacomputer with two NIC cards can function as a
transfer over the network.gateway. Router acts as a gateway e.g a router
HUBS: Hub is a simplest network device. Thethat routes the data from a IPX network to a IP
function of the hub is broadcasting i.e data isnetwork is technically a gateway. The same can
forwarded towards the all ports of a hub,be said of translational switch converts from a
regardless of whether the data was intended forEthernet network to a token ring network.
the particular systems in the network or not.CABLES: There are two most common types of
Computers in a network are connected to a hubthe cables. 1. 10baseT and 10base2. 10baseT is a
with a twisted pair (CAT5) cables. There are twofour paired cable. 10baseT has further two types
types of the hubs. 1. Active Hubs. 2. Passive Hubs.1. UTP (unshielded twisted pair) and 2. STP
SWITCHING HUB: The Switching hub (also called(shielded twisted pair. STP is most secure cable
"switch" is the most advance shape of the basiccovered with the silver coated twisted paper to
hub. In a basic hub all the computers areprotect the cable. On the other end Thin 10base2
connected with the hub and the speed of thelooks like the copper coaxial cabling that often
network is defined by the slowest computerused to connect TV sets and VCR. 10baseT/Cat5
network card connected. For example if you havecables are most commonly used cables to
10/100 Mbps cards in a network and only oneconnect the computers. It has the connector, (like
card of 10Mbps speed then the system cannota telephone connector) called RJ45 connector.
run faster than the 10 Mbps. Now if you have aTwisted pair cables are ideal for the small,
switching hub in a network, it will allow all themedium or large networks.
faster connections in the network to remain at