LESSON 71
LOCAL AREA NETWORK (LAN)
Local Area Network (LAN) 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.
LESSON 72
METROPOLITAN AREA NETWORK (MAN)
First, you have to understand the word metropolitan. Metropolitan describes
important cities such as Kuala Lumpur, Manila, Singapore, Tokyo, London and New York.
MAN 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.
MAN can be defined as a group of computers and network devices connected together within a large physical area.
LESSON 73
WIDE AREA NETWORK (WAN)
WIDE AREA NETWORK (WAN)
Wide Area Network (WAN) is 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.
LESSON 74
DIFFERENCES BETWEEN TYPES OF NETWORK
DIFFERENCES BETWEEN TYPES OF NETWORK
SETTING UP COST
Setting up a MAN network is more expensive than a LAN but less than a WAN. Managers have to consider the cost of buying the necessary hardware, software, medium and maintenance service for the desired network.
NETWORK SIZE
The network size of a MAN falls between LAN and WAN. As you know, a LAN usually covers only a limited area such as a school lab; a MAN will cover a greater area such as a city while a WAN will cover the largest geographical area such as the size of Malaysia.
SPEED
LAN offers the best speed in transmitting information followed by MAN and WAN. In addition, LANs are capable of transmitting data at very fast rates, much faster than data which is transmitted over a telephone line although the distances are limited.
LAN is also frequently used to provide a shared connection to other networks using a link to a WAN.
A MAN often acts as a high speed network to allow sharing of regional resources (similar to a large LAN). For larger network coverage, MAN is a better choice for a higher speed connection compared to a WAN.
TRANSMISSION MEDIA
A MAN might have more than one transmission media since it involves a combination of two or more LANs and the media used depends on the network coverage. Here, a MAN might use the twisted-pair and fibre-optics cables.
A WAN might use costly transmission medias such as
fibre-optics, radio waves and satellites, depending on their coverage.
CONNECTION LIMIT
The number of computers that can be attached to a single LAN is limited.
A MAN can have a large number of computers compared to a LAN but less
than a WAN.
A WAN can have up to billions of computers attached to it.
