This tutorial is made to provide you enough basic knowledge about the some very important networking devices such as Network Interface Card (NIC) adapters, routers, hubs, switches, modems, communication cables, LAN/WAN routers, gateway and other important networking devices. A network is basically a net of large number of computers interconnected to each other through a set of large number of networking devices. The simplest networking device ever made and known to man kind is the NIC adaptor and may you have seen it attached to many computers in various offices. Suppose you are a network design and you have to build a Local Area Network in an office, organization or home the basic things you will need to have so that you can easily build a LAN are computers, hubs, switches, network adapters, UTP/STP cables, routers, internal/external modems, connectors, cable testers and clipping tool.
Now suppose you are serving in ISP Company and you need to build a WAN for a city or a particular area the basic infrastructure and network hardware you will need routers, switches, boosters, routers at the user end, switches in the network, leased telephone lines for connectivity access and many other WAN communication devices and tools would be needed by yourself to build even a simplest WAN.
You may know that everything has many different mediums in which they can travel or communicate. Similarly for developing a network there are many different communications mediums such as Ethernet cables, copper wire, coaxial cable, fiber optic cables, leased telephone lines, and ever air is also a communication medium for the satellite, radio waves and microwave communication. In networking the most common networking medium is Ethernet cable with Ethernet or Star topology like most of the LANs in the world are built on them. Hub is a networking device that acts as a central connector in many LANs.
Hub is a central device installed in a network. If it stops working the network will stop running. The working of networking hub is very simple. It has many points. The data is sent to every point and it is forwarded to the point where the hub finds the address of the destined computer. The switch is an advanced and more redefined form of networking Hubs.
The working of a networking Hub is not much different from a Switch. The advancement in Switches is that they have switching table in them which makes a network more secure and faster. The difference is between the technology and technique through which data is sent. A Switch has the ability to store the MAC address of computers so the data will only be sent to the required point instead of sending it to every point. Talking about network devices Router is one of the very basic networking components. A router has software called routing table and the source and destination addresses are stored in the routing table.
A Router is responsible for connecting two physical and logically different networks. Routers are connected in a series in a WAN or a LAN and they are called Hop in the series. The working of Router is very simple a Router in a LAN or a WAN finds the IP address of the next hop (next router) and the data is sent toward and so on. D-Link, TP-Link, Link-Sys, Cisco and Aztech are some well known Router manufacturing companies. Routers are of two Basic types DSL routers and Wi-Fi routers. Nearly every ISP, banks, organizations, universities, End-users use Routers to connect to internet or interconnect in to their virtual private networks over the internet.
A gateway is a device or software in the network. A Gateway is responsible for connecting physically two different networks. A gateway can connect a Local Area Network to a Wide Area Network or a Virtual Private Network over the internet or it can be also used to connect to the internet itself. As described earlier that a Gateway is all the times directly connected to the internet well then it is directly exposed to the security threats which comes from the internet so a Gateway should be properly configured and secured and the in and out traffic should be monitored. If you are using a DSL connection that you will need a DSL modem which comes with the built-in function. The telephone line is connected with the DSL modem and UTP/STP cable attaches your computer with the DSL modem. Modems are the devices that are used to modulate and demodulate the data. They convert analogue signals to digital and digital signals to analogue so that signals can travel on the telephone lines.