2. Objective
☼ What is network?
☼ Types of network
☼ What components are necessary to establish a network?
☼ Description and characteristics of Network Components
3. What is Network?
☼ A network is defined as a group of two or more computer systems linked
together, via wired or wireless functionabilities.
☼ Shares and exchanges resource, files or any sort of data. Sometimes
requested or sometimes regardlessly broadcast.
4. Types of Network
• Geographical area of coverage
• Geometrical arrangement
• Architecture
• Protocols
5. Network Components
☼ Creating a network requires
the connection of at least two
computer systems.
☼ Any device or piece of
hardware needed to
establish a network is called
“Network Component”.
7. Cables
• Cable is one way of transmission
media which can transmit
communication signals. The wired
network typology uses special type
of cable to connect computers on a
network.
• Popular cables are Twisted Pair
Wire, Co-axial & Fibre Optic
cables.
8. Twisted Pair Wire
• Classified as Category 1, 2, 3, 4, 5, 5E, 6
and 7.
• Category 5E, 6 and 7 are high-speed
cables that can transmit at 1Gbps data
rate and more.
9. Advantages & Disadvantages
Inexpensive and readily
available
Flexible and light waight
Easy installation
Susceptible to electical
interference known as “noise”
Low bandwidth
Easily damaged
10. Co-axial Cable
• Copper cables built with a
metal shield and other
components engineered to
block signal interference.
• One physical channel that
carries the signal,
surrounded by a layer of
insulation, a second
concentric physical channel
as ground, both running
along the same axis.
11. Advantages & Disadvantages
Faster data transmission than
Twisted Pair technology.
Moderate level of “noise”
interference.
Can be used for long range data
transmission.
Single cable failure can take
down entire network.
Costlier than Twisted Pair
wiring.
High maintenance cost.
12. Optical Fibre Cable
• High-speed cable which
transmits data using light
beams through a glass
bound fibers.
• Higher data transmit rate
than any other cable
technology.
13. Advantages and Disadvantages
Extreme high speed connection.
Zero possibility of data loss -
regardless of distance.
Immensely coslty cabling
method.
Can only be installed and
regulated under governmental
jurisdiction.
14.
15. Hubs
• An old network device which
divides the connection into
various computer systems.
• Recieves requests and
responds with broadcasting
the signal, each computer in
the network should figure out
whether the broadcast data is
for them or not.
• Currently Hubs are becoming
obsolete and replaced by more
advanced communication devices
such as Switchs and Routers.
16. Broadcasts to all the ports
Almost no configuration
Active hubs can extend maximum
network media distance
No processing is done at hub
Can not identify devices
Runs in Half Duplex
divided bandwidth into ports, thus
makes each peer slower.
Availability of only 4 - 8 ports losing its
popularity.
Advantages and Disadvantages
17. Switches
• A device that channels
incoming data from any
of multiple input ports to
the specific output port
that will take it toward
its intended destination.
• Determines where to send each
incoming message frame by
looking at the Media Access
Control (or MAC address) to
identify devices and propagates
signal toward that specific
machine.
18. Advantages and Disadvantages
Betters performance by
increasing available
network bandwidth, unlike
Hubs.
Reduces the workload on
individual computers.
Network experiences fewer
frame collisions because
switches create collision
domains for each
connection (a process
called microsegmentation)
Significantly more expensive
than Bridges.
Network connectivity problems
can be difficult to trace through a
switch.
Broadcast traffic may be
troublesome.
19. Modems
• “Modulator Demodulator”, a
Converts digital signals from
one device into analog and
vice-versa, so that another
device can read.
• For example, a modem may
covert the digital data of a
computer into an analog
signal that can be read and
carried by a telephone line.
• Dial-Up Modems
• Broadband Modems
20. Advantages and Disadvantages
Time saving internet
connection through existing
telephone or cellular
connection.
Extremely cheap.
User friendly installation.
Slow speed when compared to
Hub.
Acts just as an interface between
LAN & Hub.
Works in hallf-duplex mode, user
has to wait for response.
21. Routers
• Highly intelligent devices that
connect multiple network
types and determine the best
path for sending data.
• Intemediates between at
least two networks,
commonly two LANs or
WANs or a LAN and its ISP.
22. Advantages and Disadvantages
Sophisticated routing, flow control
and traffic isolation
Easily configurable, allows network
manager to admininstrate based on
routing decisions.
Allows active loops, so redundant
paths are available
Protocol dependent devices that
must understand the protocol they
are forwarding
Can require a considerable amount
of configuring in the initial setup
Relatively complex devices, and are
expensive than Bridges
23. Network Interface Card (NIC)
• Network adapter is a device
that enables a computer to
talk with other
computer/network. Using
unique hardware addresses
(MAC address) encoded on
the card chip, the data-link
protocol employs these
addresses to discover other
systems on the network so
that it can transfer data to
the right destination.
• Wired & Wireless NICs