Transcript Network Devices (Part-2)

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. Internetworking devices is a widely used term
for any hardware within a networks that
connect different network resources. when
two or more separate networks are connected
together to share data or resources ,it
becomes an internetwork or internet.
connecting separate networks into internet
requires internetworking devices
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HUB
REPEATER
BRIDGE
ROUTER
GATEWAYS
NETWORK INTERFACE CARD
MODEM
SWITCH
WIRELESS ACCESS POINT
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Hub is a networking device .
It is also a broadcasting device.
Hub operates at physical layer of OSI Model.
It is just a connector and connects the wires
coming from different sides.
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• In a star topology Ethernet LAN ,a passive hub
is just a point where signals coming from
different stations collide. Therefore ,Passive
hub is a the collision point.
• Such a hub is part of the transmission media.
• Hub connect computers together in the star
network topology.
• If a network is connected using Hub then it
increases the chance of collisions.
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• Switch is a networking device.
• Switch operates at Data Link Layer of OSI Model.
• Switch is a device used to connect network devices
together.
• A switch acts as a central connection point for cables
from network devices.
• Unlike ,hub a switch does not broadcast the message
to all the ports, instead it forwards to the intended
port.
• So it is faster than hub.
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HUB
SWITCH
1). HUB is a broadcasting
device.
1). SWITCH is a point to point
communication device.
2).HUB operates at physical
layer of OSI Model.
2).SWITCH operates at Data
link layer of OSI model.
3).It is not an intelligent device,
so it is cheap.
3).SWITCH is an intelligent
device ,so it is an expensive.
4).HUB cannot act as
REPEATER(that is generates the
original bit pattern).
4).SWITCH can be used as
REPEATER to regenerate the
original bit pattern.
5).HUB simply broadcast the
incoming packet.
5).SWITCH uses switching table
to find out the current
destination.
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• Gateway are the internetworking devices .
• It operates at the seven layer of OSI
model.
• A gateway act as the protocol converter.
• It is used to connect to different types of
networks,that uses different protocol.
• Gateway can perform all functions of Bridges
and routers.
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• A bridge is a networking device .
• It operates both at the physical and data link
layer of OSI Model.
• Bridge can be used to divide a large network
into smaller segment.
• As a physical layer device ,a bridge regenerate
the signal.
• As a data link layer device ,a bridge can access
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• Physical or MAC (Medium access
control)address of the stations attached to it.
• It can check the destination address of the
frame .
• A bridge can maintain table of MAC address
of various stations.
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• There are two types of bridges:
• 1) Transparent Bridges.
• 2)Source Routing Bridges.
• A Transparent Bridge is invisible to the
network ; the stations in the network are
completely are unaware of bridges
existence.
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• In transparent bridge route is decided by the
bridges.
• The transparent bridge architecture is defined in IEEE
802.1d.
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Source routing bridge were designed by IEEE.
In this route is decided by the end station.
Bridges are not transparent to end station.
The source can select an optimum path from a
choice of route.
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• A repeater is also known as regenerator.
• It is an electronic device that operates only
Physical layer of the OSI Model.
• Signal can carry the information within a
network only for a fixed distance.
• After this distance attenuation occur ,and the
signal becomes weak and corrupted.
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• The purpose of repeater is to take this signal
(before it becomes to weak or corrupted)and
regenerate the original bit pattern.
• Repeater does not understand the frame
format and also Physical address.
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SR
No
BRIDGE
REPEATER
1)
Bridge is the hardware device
that operates at both physical
and data link layer of OSI
Model.
Repeater is the hardware device
that operates at physical layer.
2)
Bridge use MAC address of the
stations to deliver packets to
destination
Repeater can not understand the
physical address or MAC address
Of station.
3)
The Bridge can understand the
frame format.
Repeater can not understand the
frame format.
4)
Bridge perform packet filtering.
Repeater does not perform packet
filtering.
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• Network interface card is a hardware card
installed in a computer, so it can communicate
on network.
• The network adapter provides one or more
ports for the network cable to connect and
transmit and receive data onto the cable.
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• Routers are multi port devices.
• They operate at physical ,data link ,network
layer of OSI Model.
• A router may connect LAN and WAN in the
internet.
• A router has access to the network layer
address or logical address(IP address).
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• It contains a routing table that enable it to
make decisions about the route.
• These routing tables are dynamic are updated
Using routing protocols.
• Routers act like station on a network.
• The router are usually member of more than
one network at the same time.
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SR
No.
ROUTER
BRIDGE
1)
Router is a hardware device
that operate at physical
,network and data link layer.
Bridge is a hardware device that at data
link layer and physical layer of OSI
Model.
2)
Router interconnects two or
more network s and route
packet between them.
Bridge is used to divide large network
into smaller segments.
3)
Expensive
Inexpensive
4)
Difficult to setup and
configure.
Easy to configure.
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• A wireless
network adapter card with a
transceiver called and broadcast and receive
signal to and from the surrounding computers
and passes back.
• Access point act as wireless hub to link multiple
wireless NIC into a single subnet.
• Access point also have at least one fixed Ethernet
port to allow the wireless network to be bridge to
a traditional wireless Ethernet network.
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• The term “Modem” is derived from the words
Modulator and Demodulator.
• Modulator converts a digital signal into an
analog and demodulator converts an analog
into a digital.
• The modem at transmitting end converts the
digital signal generated by DTE (data terminal
Equipment).
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B
A
Digital signal
Analog
signal
Digital signal
Telephon
e lines
Modulation/demodulation
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• Multiplexing is done by using a device called
multiplexer.
• That combines n input lines to generate one
output line i.e.(many to one).
• Therefore ,multiplexer has several input lines
and one output.
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• At the receiving end, a device called demultiplexer (DEMUX) is used that signal into
its component lines.
• It is a reverse of the MUX.
• So, DEMUX has one input and several
outputs
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Single communication channel
Carrying 4 different
transmission
N inputs
One input
One output
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N inputs
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