Network Device



There are several hardware used in the networking.


·        Servers

Mail Seraver

A computer that information to connected computer, such as Webs servers, mail servers and LAN servers. The typical server is a computer system that operates continuously on a network and waits for requests for services from other computer on the network. Many servers are dedicated to this role, but some may also be used simultaneously for other purposes, particularly when the demands placed upon them as servers are modest. For example, in a small office, a large desktop computer may act as both a desktop workstation for one person in the office and as a server for all the other computers in the office.

Web Server

Servers today are physically similar to most other general-purpose computers, although their hardware configurations may be particularly optimized to fit their server roles, if they are dedicated to that role. Many use hardware identical or nearly identical to that found in standard desktop PCs. However, servers run software that is often very different from that used on desktop computers and workstations.


Servers frequently host hardware resources that they make available on a controlled and shared basis to client computers, such as printers and file systems. This sharing better access control and can reduce costs by reducing duplication of hardware.


·        Network Printer

Network Printer

Printers are connected to a network to help reduce printing costs. Each user on the network would require his/her own printer, if he is not using a network printer.

Most network printers can be connected directly to the network using a network adapter. The network cable is plugged into the network adapter at the back of the printer. Most network printers can be connected to several different types of network.


·        Print Server

Print Server

A print server is a host computer or device to which one a more printers are connected and that can accept print jobs from external client computers connected to the print server over a network. The printer server then sends the data to the appropriate printer it manages.



·        Network Interface Card

Network Interface Card

A network card, network adapter or NIC (Network Interface Controller) is a piece of computer hardware designed to allow computers to communicate over a computer network.

Whereas network cards used to be expansion cards that plug a computer bus, the low cost and presence of the Ethernet standard means that most newer computers have a network interface built into the motherboard.


Once a network interface card is manufactured, it is given a unique hardware address. The hardware address is helpful in identifying the network interface card when information is being sent or received on a network. Network interface cards come with drives for different types of operating system. A drive is the software that lets the operating systems exchange information with the network interface card performs card. To make sure that the network interface card preforms card. To make sure that the network interface card performs optimally, the correct drive must be installed. If the operating system interface card has been added to the computer, you will have to install the drive manually.


Wireless Notebook Network Card

A Wireless network interface controller (WNIC) is a network card which connects to a radio-based computer network, unlike a regular network interface controller (NIC) which connects to a wire-based network.

Wireless Desktop Network CardA WNIC is an essential component for wireless desktop computer. This card users an antenna to communicate through microwaves.




·        Hubs


A hub offers a central location where all the cables on a network meet. Hubs are found on most modern networks. Earlier, only star network structures used hubs. Now it is very common to use hubs to connect computers. Many types of network structures are now using hubs as the primary method of connecting computers.

A hub has sockets or ports where cables from computer devices can be plugged in. houbs commonly have 4, 8, 16, or 24 ports Usually each port has an indicator light, called a Light Emitting Diode (LED). It lights up when a computer is attached to the port and turned on. Some LEDs indicate when information is being shifted through the port.


Connecting two or more hubs is referred to as daisy chaining. A large hub can attach up to 24 computers. If a network has more then 24 computers, it can use two or more hubs connected together.


Adding, moving or removing a computer from a hub or a series of hubs is quite simple. A cable can easily be removed from a port on one hub and plugged into a port on another hub. There is no need for the network to be shut down or disrupted during reconfiguration.


·       Switches



A network switch is a networking device that performs transparent bridging at up the speed of the hardware. Common hardware includes switches, which can connect at 10, 100 , or 1000 megabits per second, at half or full duplex means that the device can only send or receive, at the same time. Switches can be used in place of hubs.


When network is expanded to adjust new users and more sophisticated applications, the amount of information being sent may exceed the amount of information, the network was originally designed to handle. This can cause congestion and reduction in the performance of the network. Replacing the hubs on an overloaded network with switches can increase the efficiency of the network. When you replace hubs with switches, you usually do not have to replace other elements of the network such as the cable system.


Security: Switches can help ensure that the information user’s shift over a network is secure. Unlike a hub. Which transfers information to every computer on the network segment, a switch sends data to the intended recipient only.



·        Routing Switches:

Routing Switches

Some switches, called routing switches, have capabilities that are similar to those of a router. Routing switches can direct or route information to the intended destination on a network. Routing switches may also be able to find the most efficient route for information to transverse.



·        Repeaters


A repeater is an electronic device that receiver a weak or low-level signal and retransmits it at a higher level or higher power, so that the signal can cover longer distances without degradation. They are used to interconnect segments in LANs and extend WAN transmission.


The signal will become weaker, the more it travel along a cable. This is often referred to as attenuation. Repeaters prevent problems that might result from weak signals by strengthening the signal.


Repeaters are used to extend the length of the cable that connect computer devices together on a network. Repeaters are especially useful in areas where long lengths of cable are required to connect computer devices together, such as a network in a large warehouse.


  • Bridges


A device that connects two networks into one large logical so that information can flow between them.

Bridges are helpful in connecting a small number of individual networks to make them work together as one large network. A network comprising smaller networks is called an internetwork.


Bridges are also helpful in breaking a busy network into smaller segments. Breaking a busy network is helpful in reducing excess network traffic. For example, if the computers in one department generate a lot of network traffic, a bridge can separate that department from the rest of the network.


·        Routers


A router is a computer networking device that forwards data across a network toward their destinations, through a process known as routing.

A router acts as a junction between two or more networks to transfer data packets among them. A router is different form a switch. A switch connects devices to from a local area network (LAN). One easy illustration for the different function of routers and switches is to switches as neighborhood streets, and the router as the intersections with the street signs.

A large network may have more than one route that information can take to its intended destination. There are some routers that can automatically detect if a part of the network is malfunctioning around the problem area so the impact of the network failure will be minimal. Routers are said to be intelligent because they can analyze a network to determine the best route for information to take.


Types of routers:  Most routers can automatically determine the best route for information. With older routers, called static routers, a network administrator had to manually configure the router to recognize each router information could take. Newer routers, called dynamic routers, automatically create and maintain a table of the available routes on the network.


Wide Area Network (WAN) : Routers are helpful in connecting local area networks to a wide area network. Routers are also helpful in splitting a wide area network info segments. This helps reduce the amount of information being transferred over the network and improves the efficiency of the WAN.