Computer Networking-Types of Network

Computer Networking-Types of Network

What is Network?

An interconnection of computer and pheriperal devices with carriers and data communication devices for the purpose of exchanging data or information is known as Network.

"A computer network is simply a group of computers that are so connected that resources than can be shared and information can be exchaned."

Need of Networking

The major reasons for need of networking are as follows-

Resource Sharing

The aim is to make all programs, data and pheripherals available to authorised user on the network irrespective of physical location of resources.

Realiability

This is provided by having an alternative source of data available for use, e.g. file can be replicated onto 3 pcs, so that if one of them is unavailable due to hardware failure, the other PC can be used.

 Financial Benefits

Small computer have better price to performance ratio as compared to large ones.

 Better Communication Medium

In an organisation with a number of branches os for off places, networking of computer facilities cheap and easy mode of communication. It is possible to transfer any kind of information to any other destination immediately.

Access to remote data base

By getting access to remote data base it is possible to get rid of unnecessary trouble and wastage of precious time. From a remote place in any part of world a user can book a flight ticket, accomodation in hotels and so on.

Types of Network 

On the basis of geographical area, network can be categoriseed into-

• LAN (Local Area Network)
• MAN (Metropolitan Area Network)
• WAN (Wide Area Network)

S.No.	Particulars	LAN	MAN	WAN
1	Full Form	Local Area Network	Metropolitan Area Network	Wide Area Network
2	Location	Located in Buildings,Offices etc.	Within a  city	Worldwide or Global
3	Connection	No Modem Require	Modem telephone require	Satellite connection and other devices
4	Data rate	High Data rate upto 100 Mbps	Less than LAN	Lowest Data rate
5	Installation	Easy to install	Less Easy	Difficult
6	Errors	Less errors	Error Occurs	High rate of Errors

LAN

Local Area Network is usually, privately owned by and links the devices in a single office, building or campus depending on needs.

LAN is a computer network that spans a relatively small area LANs are capable of transmitting data at very fast rate, much faster than what can be transmitted over a telephone line. Different  kinds of protocols are there  (Ethernet taken ring etc.) each with their own advantages and disadvantages.

Maximum Data transfer rate is upto 100 Mbps.

 

Advantages of LAN (Local Area Network)

LANallows sharing of expensive resources e.g. coloured,lajer printers and high capacity mass storage devices among a number of users.

LANs allows high speed of exchange of communication between key people in an organisation.

LAN contributes in increasing productivity.

LAN provides the catalyst to increase the range of  potential applications for the PCs where an application package can be used by users.

 Disadvantages of LAN (Local Area Network)

The financial cost of LANs is still high.

LAN software requires memory space in each of computer used on network.

LAN adds another level of complexity of computer operations.

You may face a situation where, the entire network suddenly locks up because one user has made a mistake.

Some kind of security system must be implemented in order to protect confidential data.

MAN

A Metropolitan Area Network is designed to extent over an entire city. It may be single net such as cable TV net or it may be a means of connecting a no. of LANs to form a large network. MANs are usually characterised by very high connection by fibre optic cable or other digital media.

A MAN can support both data and voice.

WAN

Wide Area Network It provides long distance transmission of data, voice , image over large graphical areas that may compromise a country , continent or even whole world computers of WAN are usually connected through public network such as telephone systems, leased lines or satellite e.g. indonet, banking, networks, stock, brokerage, network.

Types of Wide Area Network

There are two types of WAN-

• HierarchialNetworks
• Distributed Data Processing Networks

Short Notes on Computer Networking

Nodes

The PCs and the servers are known as network devices or network nodes. In general, a device or node is connected directly to a network cable or data path.

Host

The term host refers to a microcomputer attached to a network device. It may also refer to the native operating system on a workstation.

 Workstation

A work station is a powerful PC used for a node on a network primarily used to run application program. PCs can be used as a work station.

 Bandwidth

It refers to a difference between the highest and the lowest frequencies of a transmissions channel.

"A channel is the medium used to carry information or data from a point to another."

Broadband

In telecommunication , broadband is wide brandwidth data transmissions which transports multiple signals and channels.

Interoparability 

It is the capability to communicate , execute programs or transfer data among various  functional units in a way that requires the user to have little or no knowledge of the major characteristics of those units.

NetworkAdministrator

Network Administrator is a person who manages the maintenance and use of a network. Network management refers to maintenance and administration of large scale computer network and tele-communication networks at top level.

 It includes performance of following functions-

• Initial Network planning
• Frequency allocation, predetermined traffic routing to support load balancing.
• Gyptographic key distribution authorization.
• Configuration Management.
• Fault Management
• Security Management
• Performance Management
• Bandwidth Management
• Accounting management