Basic of Networking
1. What is Networking?
2 .Networking Devices
3 .The OSI Reference Model
4 .Networking Topologies
1.What is Networking?
A Network is nothing but a collection of computers connected together. (This connection may be wired or wireless or both.)
Networking is the process of communication between inter-connected devices, mainly for the purpose of Sharing Network Resources.(This just means that if you have a Network of Computers, you can actually Share Resources – for example: if you have a network of, say 10 computers, you can have just one printer and share it on your network (instead of having 10 different printers for each individual computer). You can also share data: let us take another example here: If you wanted to share an important file with a colleague in your department – you can just share it over the network – as against copying it to a floppy disc or CD and manually transferring to your colleague’s computer.)
What are the different types of networks?
There are three types of networks.
They are:
LOCAL AREA NETWORKS (LAN): A LAN is nothing but a group of computers connected together within the same geographical area. It can span upto 2 kilometers.
The Main Components of a LAN are:
NIC (Network Interface Card)
Cable (Co-axial, Cat 5 or Cat 6)
Hub or Switch
METROPOLITAN AREA NETWORKS (MAN): This is a Combination of LANs and WANs ands can be located in different parts of the same city.
The Main Components of a MAN are:
Router
BRouter (A BRouter is nothing but a combination of a Bridge and a Router.)
Switches
DSL Connectivity (DSL stands for Digital Subscriber Link)
WIDE AREA NETWORKS (WAN): This refers to the Interconnection of LANS or MANS and can be located within the same Geographical Area or in Different Geographical Areas.It depends on Telecommunication Services for Connectivity.
The Main Components of a WAN are the same as in WAN.
What is Internet?
The Internet can be defined as a Network of Networks.
2.Networking Devices
Some of the important Networking Devices are:
Hubs
Hubs: These are simple network devices which facilitate communication between two or more computers in a network. These devices are generally used in small networks. Hubs follow Broadcasting to transmit data – which means data sent from one computer through a hub is transmitted through all the ports in the Hub. The image below shows a typical 8 port hub – you can connect 8 computers to it using ethernet cables. Hubs generally come with 4, 8, 16 or even 24 ports.
Switches
Switch: It is also a device which allows computers to connect to it using ethernet cables, just like the hub. But a Switch is more intelligent than a hub – it uses Unicast to transmit data. But, unlike the Hub where data is sent out to all the ports, a switch forwards data only to the target computer. This is how it is done – a switch maintains a table called Mac Information Table (MIT) which gets generated as soon as the switch is turned on. This MIT acts like an Index table which contains the Port Number, IP address and MAC Address of all the computers connected to the switch. Using a switch, you can monitor the usage of your network and also control access to different parts of your network. Switches allow much faster data transfers than hubs. The image below shows a typical 24 port switch. A switch might look similar to a hub – but functionally, it is very different and much more advanced, so don’t get confused.
Routers
Routers: These are devices that connect two different networks and Routing is nothing but the process of communication between different networks. For example, using a Router, you can connect a Class A Network with a Class C network. A Router can be wired or wireless.
NICS (Network Interface Cards or just plain Network Adapters.)
NICs (Network Interface Cards): A NIC is by far, the most important Networking Device which allows your computer to physically connect to a Network. Most computer motherboards today, come with built-in NICs. But you can also buy a NIC which you can fix in one of the PCI slots of your computer’s motherboard.
Integral Informations 