22-05-2014, 10:18 AM
Introduction to Computer Networks
Computer Networks.ppt (Size: 355 KB / Downloads: 9)
Computer Network
A computer network is a group of interconnected computers.
It allows computers to communicate with each other and to share resources and information.
First Network : The Advanced Research Projects Agency (ARPA) funded the design of the "Advanced Research Projects Agency Network" (ARPANET) for the United States Department of Defense
Data Communication
Exchange of data between 2 devices via some transmission media
DC depends upon 3 characteristics:
Delivery
Accuracy
Timeliness
Data Communication Model
Source
generates data to be transmitted
Transmitter
Converts data into transmittable signals
Transmission System
Carries data
Receiver
Converts received signal into data
Destination
Takes incoming data
Local Area Network (LAN)
Systems are close to each other
Contained in one office or building where 2 or 3 or several hundred computers of different types are interconnected
Organizations often have several LANS
Wide Area Networks (WAN)
Two or more LANs connected
Over a large geographic area
Typically use public or may be private
Cable TV network also a WAN that spread over a city
The Internet is a WAN