A
network is a collection
of computers and devices connected together via communications devices and
transmission media.
Basic concept of network.
•Usually, the
connections between computers in a
network are
made using physical wires or cables.
•However,
some connections are wireless,
using radio
waves or infrared signals.
Application of network.
•Resource Sharing
qHardware (computing resources, disks,
printers)
qSoftware (application software)
•Information Sharing
qEasy accessibility from anywhere (files,
databases)
qSearch Capability (www)
•Communication
qEmail
qMessage broadcast
Network perspective
Based on transmission media
Based on network size
Based on management method
Based on topology
Based on network size
Based on management method
Based on topology
Communication device
A
communications device is any type of hardware capable of transmitting data,
instructions, and information between a sending device and a receiving device.
Dial-up Modem
A communications device that can convert digital signals to analog signals and analog signals
to digital signals, so that data can travel along an analog telephone line.
Digital Modem (ISDN,DSL, Cable Modem)
to digital signals, so that data can travel along an analog telephone line.
Digital Modem (ISDN,DSL, Cable Modem)
A
communications device that sends and receives data and
information to
and from a digital
line.
Wireless Modem
Some mobile users have a wireless modem
that uses the cell phone network to connect to
the Internet wirelessly
from a notebook computer, a smart phone, or other mobile device.
Router
A communications device that connects
multiple computers or other routers together and
transmits data to
its correct destination on a network.
Switch
A connection device similar
to a hub but more sophisticated, including functionality that
allows it to control and manage data transmissions.
Hub
A connection device that allows
multiple connections to the network.
TRANSMISSION MEDIA
Materials
or substances capable of carrying one or more signals in a communications
channel.
