COMPUTER NETWORK & � ITS BUSINESS APPLICATIONS

COMPUTER NETWORK

• A computer network is a system of interconnected computers and peripheral devices.
• For example, it may connect computers, printers, scanners and cameras.

COMMUNICATIONS

• Communications is about the transfer of information from a sender, across a distance, to a receiver.
• Communication is an act of transmitting messages.

COMPUTER NETWORK COMMUNICATION

• We transmit information or data by using two types of signals, namely analog and digital.
• Computers communicate with digital signals.
• The older forms of communications technology, such as telephones and radios, use analog signals.

TYPES OF NETWORKS

LOCAL AREA NETWORK

METROPOLITAN AREA NETWORK

WIDE AREA NETWORK

LOCAL AREA NETWORK (LAN)

• 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.

METROPOLITAN AREA NETWORK (MAN)

• ‘Metropolitan' - describes important cities like New Delhi, Mumbai, Kolkata, bangaluru, Chennai etc.
• Companies that have several branches within the Mumbai city such as banks, use a MAN.
• Can be a collection of several LANs within the same city.
• MAN can be defined as a group of computers and network devices connected together within a large physical area.

WIDE AREA NETWORK (WAN)

• The largest network of all network types.
• Internet is the largest WAN in the world.
• WAN generally covers large distances such as states, countries or continents.
• Eg: 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.
• WAN is a group of MANs or LANs or the mixture of both networks.

COMPARISON OF LAN, MAN, WAN

NETWORK ARCHITECTURE

NETWORK ARCHITECTURE

• Overall design of a computer network that describes how a computer network is configured and what strategies are being used.
• Mainly focuses on the functions of the networks.
• Also known as network model or network design.

NETWORK ARCHITECTURE

CLIENT/SERVER NETWORK

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• A client/server network is a network in which the shared files and applications are stored in the server but network users (clients) can still store files on their individual PCs.
• A server is a computer that shares information and resources with other computers on a network.
• A client is a computer which requests services or files from a server computer.

NETWORK ARCHITECTURE

Peer-to-peer or P2P

• It is a network with all the nodes

acting as both servers and clients.

• A PC can access files located

on another PC and can also provide files to other PCs.

• All computers in the peer-to-

peer network has equal

responsibilities and capabilities

to use the resources available on the network.

• With peer-to-peer network, no

server is needed; each

computer in the network is called a peer.

DIFFERENCES

NETWORK TOPOLOGY

BUS TOPOLOGY

• DESCRIPTION OF BUS TOPOLOGY
• Very common in LAN.
• Must have a common backbone (the central cable) to connect all devices.
• All nodes share the backbone to communicate with each other on the network.
• Sometimes, a bus network has more than one server. Sometimes, a server is not needed on the network.

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A bus topology consists of a single central cable to which all computers and other devices connect. A bus topology is also known as a bus network.

RING TOPOLOGY

A ring topology consists of all computers and other devices that are connected in a loop. Ring topology is also known as a ring network.

DESCRIPTION OF RING TOPOLOGY

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• Can be found in LAN.
• Each node directly connect to two neighbouring nodes.
• A server may exist in a ring network, but it will not connect to all the nodes in the network.
• The server, like other nodes, will only communicate to its two neighbouring nodes

STAR TOPOLOGY

A star topology consists of a central host which acts as the centre, and all nodes connect to the host. A star topology is also known as star network.

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DESCRIPTION OF STAR TOPOLOGY

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• A star network is found in a Local Area Network setting.
• A star network must have a host which acts as the centre.
• The host can be a server, hub or router.
• In a star network, every node will not connect to the neighbouring nodes.
• Every node must connect to the host in order to communicate.
• The host will control the flow of communication in the network.

TREE TOPOLOGY

Tree topology is the combination of the bus and the star topology. The tree like structure allows you to have many servers on the network and you can branch out the network on many ways. Also known as hierarchical network.

DESCRIPTION OF TREE TOPOLOGY

• Nodes of some devices are linked to a centrally located hub which is called the active hub.
• The active hub has a hardware device called the repeater.
• This strengthens the transmission and increase the travelling distance of a signal.
• The secondary hub can isolate communications between different computers.

MESS TOPOLOGY

Mesh Network is a network where all the nodes are connected to each other and is a complete network. In a Mesh Network every node is connected to other nodes on the network through hops. It is called the self healing technology where it receives data one way or the other.

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DESCRIPTION OF MESS TOPOLOGY

• Data is automatically configured to reach the destination by taking the shortest route.
• The reliability factor is high in any kind of Mesh Network.
• The Mesh Network is based on a very sensible concept and has lesser chances of a network breakdown.

APPLICATIONS OF COMPUTER NETWORK

• File sharing.
• Printer sharing.
• Communication and collaboration.
• Remote access.
• Data protection.
• Centralized Support and Administration.