3.1.3.1 Define types of computer networks:
Local Area Network (LAN)
A LAN covers a small region of space, typically a single building ~ Eg: within a school lab.
Metropolitan Area Network (MAN)
A MAN is a collection of LANs with the same geographical area, for instance a city ~ Eg: within a a city
Wide Area Network (WAN)
A WAN can be a collection of LANs or MANs or the mix of two with a very large geographical area, for instance a country or even beyond the border ~ Eg: between KL and London
3.1.3.2 Differentiate between the three types of computer networks.
LAN is a group of computers and network devices connected together, usually within the same building. It is the smallest network compared to the other two networks. The simplest form of LAN is to connect two computers together. LAN is operated within a limited physical area, such as at home, school, a single building or several buildings. A network which consists of less than 500 interconnected devices across several buildings, is still recognised as a LAN.
Inexpensive hardware used in LAN previously include twisted pair, coaxial cables and the higher end is fiber optic or wireless. However, coaxial cables are now being replaced by a higher speed cabling system such as CAT5 using RJ45 connectors.
LAN is a very high speed network (from previously 10Mbps) to 100Mbps, which is faster than MAN and WAN.
MAN can be defined as a group of computers and network devices connected together within a large physical area. It is a network of computers located at different sites within a large physical area, such as a city. Companies that have several branches within the Kuala Lumpur city such as banks, might find a MAN useful to them.
In this case, setting up a MAN across long distances can be best connected using fiber optics. Sometimes, a MAN can be a collection of several LANs within the same city. MAN often acts as a high speed network (although not as fast as a LAN) to allow sharing of regional resources.
WANis the largest network of all network types. The Internet is the largest WAN in the world. WAN generally covers large distances such as states, countries or continents.
An example in the society using WAN is the banking organisation. Local banks have always maintained their business online by connecting all computers of their branches in the countries. International banks also use WAN to connect their computers all over the world.
Actually, WAN is a group of MANs or LANs or the mixture of both networks.
A device called a router is needed to connect the MANs and LANs all over a large physical area. A router is a special networking device that connects two or more different networks and keeps data flowing between them.
A router makes all the different networks communicate, such as connecting LAN to LAN, LAN to WAN or WAN to WAN. The transmission media in WAN uses the fibre optic cable. WAN is still considered a fast network with speeds 20 – 2000 Kbps, but slower than LAN and MAN.
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