Computer Network TOPOLOGY

TOPOLOGY:
    The method of connecting different terminals for transmitting data from one computer to another is called network topology or network types or network technology.
    Topology refers to how the computers in a network are configured in their connections with each other.
    Physical layout of the computer network. The term topology is the way of connecting computers or nodes on a network. There are many ways in which computers can be connected together in a computer network. The way in which computers or other devices are connected in a network is called network topology.
There are following main types of topology.
1.    ) BUS           Network    Topology.
2.    ) STAR         Network     Topology.
3.    ) RING         Network     Topology.

1= BUS (LINEAR) NETWORK TOPOLOGY:
In bus network topology, each terminal is connected to the central computer with one or two cables. A common bus is used in this type of network topology. If one cable has become defective, the terminals connected to that cable loses connection with the central computer, but other computers remains in connected. This topology is mostly used in business.

ADVANTAGES:-
    Easy to connect a computer or peripheral devices.
    Requires less cable length.
    Inexpensive hardware devices.
    Adding additional computer easily.
    Easy to extend a bus, two cables can be joined with a connector.

DISAVANTAGES:-
    Entire network shuts down if there is a break in the main cable.
    Terminators are required at both ends of main cable.
    Difficult to identify the problem if the entire network shuts down.
    Heavy network traffic can slow a bus considerably.
    Each connector reduces the strength of the electrical signal
    As the number of computer increases, the speed of the network slows down.


(BUS NETWORK TOPOLOGY)

2= STAR NETWORK TOPOLOGY:
In star network topology, each computer or terminal is directly connected to the Central controller Unit (HUB) through an individual cable and Hub is connected to the central computer (file server or main computer).If one of computers has become defective, than there is no any effect on star network topology .This type of networking most expensive because each computer has a separate cable for connection.




(STAR NETWORK TOPOLOGY)

ADVANTAGES:-
    Easy to install, modify and add new computers without disturbing the rest of the network computers.
    Easy to detect faults and to remove parts.
    Hub can accommodate multiple cable types.
    It is more flexible among the remaining topology.
DISADVANTAGES:-
    Requires more cable length than a linear topology.
    If the hub or central computer fails, the entire network breaks down.
    More expensive than bus topology.
3= RING (TOKEN )NETWORK TOPOLOGY:
in a ring topology , computers are connected on a single of cable .Each computer repeats and keeps the signal strong .No terminator is required. Each node most determines whether or not any received data is for its use and if not, it passes the data on to its neighbor.

ADVANTAGES:-
    All connected computer have equal. access and has the same opportunity to transmit.
    Adding additional nodes easily.

DISADVANTAGES:-
    It is difficult to configure.
    Media failure can stop all communication.
    Problem detection and solving is difficult.
    Adding or removing computers disrupts the network.




ANALOG DATD TRANSMISSION
The transfer of data from one place to another in continuous wave from is called analog data transmission .The analog signal consists of continuous electrical wave or signals constantly very in one or more values and these changes in values can be used to represent data. The light waves, sound wave or radio waves are examples of analog signas.The transmission through telephone lines, microwave system or satellite is the example of analog data transmission.

Analog Form:




Examples:
Measurement of Temperature, Volume, Vocal Waave, Waves, Analog Clock, Pressure, Fan Dimmer. Etc.

DIGITAL DATA TRANSMISSION
Digital data transmission system is the transmission of data from one location to another location in the from of digital signal. A digital signal consists of individual electrical pulses that represent two values like “0” for off and “1” for on.
Computer accepts the data in digital forms.

Digital Form;


Examples:
(Only two values exist.)
On/Off switch, Day/Night concept, Digital Clock, etc.

INTER-NET:
The network of networks is called internet:

Explanation:
Internet stands for International Networking.
In this case , a central computer is used as server machine and this system is attached with other  server machines through satellites. All of the Internet users are attached to their own server using telephone line with using Modem. The local server machine keeps all the accounts of all its users.-


In July-2000, 180-Billions of internet users and increasing rate of
Internet users are 10% p.a.

E-MAIL:
E-MAIL stand for Electronic Mail. It is a communication system in which data is sent and received through computer from one location to another.
In this case, a central computer is used as Post Office, and this system is attached with other Post office Machines through satellite. All of the e-mail users are attached to their own fax machine and post office using telephone lines and modem.

WEB-BROWSING:
The process of digging out information any specific subject is called web browsing.

E-COMMERCE:-
E0-Commerce stand for Electronic commerce: the need for electronic commerce stand from the demand within business and government to make better use of computing and to better apply computer technology to improve customer interacton, vusiness processes, corner)enterprises.