What are the different types of computer networks?

PAN( personal area network) : Network that is meant for one person


Eg: A wireless network connecting a computer with it’s mouse, keyboard, printer is PAN. Covers 1m distance only.



LAN (local area network) : LAN’s are privately owned network which covers a room, building or a campus ( 10m, 100m, 1km) of distance.


LAN’s are widely used in offices, companies, industries.


Characteristics:


* Lan’s are restricted in size


*Lan’s uses transmission media as cable , to which all the machine are attached.


*Lan’s basically uses Bus and Ring Topologies( network structure) to broadcast.


Traditional Lan’s runs at the speed of 100Mbps and newer Lan’s runs at the speed of 10Gbps.


Lan’s are un-switched ( they don’t have routers).




MAN (metropoliterian area network): MAN covers city ( about 10Km) in distance.


The best example of Man is the CABLE TV NETWORK available .


Cable TV is not the only MAN ,development in high speed wireless internet access resulted in MAN.


MAN’s are also un-switched ( i.e don’t have routers).




WAN (wide area network): A wide area network covers a large geographical areas like country or a continent ( about 100Km, 1000Km, 10,000Km)in distance.


In WAN, subnet consist of two components Transmission lines like copper cable, optical fiber ( move bits between machines) and Switching elements or routers (specialized computers or devices that connects 3 or more transmission lines, when date arrives to incoming line, router choose an outgoing line on which to forward them.


Hosts ( user’s computers) are connected to subnet.


Subnet is owned and operated by telephone company or isp.


The subnet is collection of communication lines and routers ( but not hosts).


The job of subnet is to carry message from host to host .


In most WAN’s , the network contains numerous transmission lines , each one connecting pair of router. If two routers do not share a transmission line , wish to communicate they must do this indirectly via other router .


When a packet is sent from one router to another via one or more intermediate routers, the packet is received at each intermediate router in its entirety , stored until the required output is free, and then forwarded.


This principle is known as “store and forward or packet switched subnet”.