2. Here’s a list of the devices
❖ HUB
❖ Switch
❖ Repeater
❖ Modem
❖ NIC(network Interface card)
❖ Transceiver
❖ Bridge
❖ Router
❖ Firewall
3. Hub
• a hub is the most basic networking
device that connects multiple computers
or other network devices together.
• Most hubs can detect basic network
errors such as collisions.
• In the past network hubs were popular
because they were cheaper than a
switch and router.
4. Hub
• a hub refers to a hardware device that enables
multiple devices or connections to be connected to a
computer.
5. HUB is classified into two types.
Active HUB
• Active hubs are a little
smarter than passive hubs.
You might also come across
the term "concentrators,"
which are basically active
hubs that concentrate and
strengthen a signal as it
enters and exits the hub.
Passive HUB
• These hubs are nothing more
than point contacts for the
wires that make up the
physical network. An example
of this is a punch-down block
that is a simple plastic,
unpowered box used to plug
network cables into.
7. SWITCH
• A network switch (also
called switching hub,
bridging hub, officially MAC
Bridge) is a computer
networking device that
connects devices together
on a computer network.
• using packet switching to
receive, process and forward
data to the destination device.
• A network switch is a multiport
network bridge that uses
hardware addresses to process
and forward data at the data link
layer (layer 2) of the OSI model.
8. SWITCH
• switches are commonly
known as layer-3 switches or
multilayer switches.
• a switch determines from the
IP address in each packet
which output port to use for
the next part of its trip to the
intended destination.
9. REPEATER
A repeater is a device that amplifies the signal from
a wireless network and operates in a combination
of bridging and access point modes.
• A repeater takes a signal
from a wireless access
point or router and
broadcasts it to wireless
clients.
A repeater does not connect to an Ethernet port,
except for when you are configuring it, so these
devices are entirely portable.
• A repeater can help you get
your wireless signal to a
remote bedroom, the
basement, or your patio,
and may allow a small
network to use a single
access point.
11. MODEM
A modem modulates outgoing digital signals from a
computer or other digital device to analog signals
• incoming analog signal and
converts it to a digital
signal for the digital device.
12. MODEM
In recent years, the 2400 bits per second modem
that could carry e-mail has become obsolete.
From early 1998, most new personal
computers came with 56 Kbps modems.
13. MODEM
using a digital Integrated Services Digital Network
adapter instead of a conventional modem, the same
telephone wire can now carry up to 128 Kbps.
• With Digital Subscriber
Line (DSL) systems,
now being deployed in
a number of
communities,
bandwidth on twisted-
pair can be in the
megabit range.
14. NIC (NETWORK INTERFACE CARD)
A network interface card provides the computer with a
dedicated, full-time connection to a network.
• A network interface card
specifically designed for
the LAN transmission
technology.
• new computers have a
network interface build
directly into the
motherboard.
Most new computers have either Ethernet capabilities
integrated into the motherboard chipset,
• use an inexpensive
dedicated Ethernet chip
connected through the PCI
or PCI Express bus.
• A separate NIC is generally
no longer needed.
15. NIC
• NIC card or controller is not
integrated into the
motherboard, it may be an
integrated component in a
router, printer interface or
USB device.
• transfer rates may be 10, 100,
or 1000 Megabits per second.
16. TRANSCEIVER
A transceiver is a combination
transmitter/receiver in a single package.
• The term applies to
wireless communications
devices such as cellular
telephones, cordless
telephone sets, handheld
two-way radios, and
mobile two-way radios.
Occasionally the term is used in reference to
transmitter/receiver devices in cable or optical fiber
systems.
• In a radio transceiver, the
receiver is silenced while
transmitting.
• An electronic switch allows
the transmitter and receiver
to be connected to the same
antenna, and prevents the
transmitter output from
damaging the receiver.
17. TRANSCEIVER
a transceiver of this kind, it is impossible
to receive signals while transmitting.
• This mode is called half
duplex.
• Transmission and reception
often, but not always, are
done on the same frequency.
Some transceivers are
designed to allow reception
of signals during transmission
periods.
18. Cellular and cordless telephone
sets use this mode.
• Satellite communications
networks often employ full-
duplex transceivers at the
surface-based subscriber points.
•
• The transmitted signal
(transceiver-to-satellite) is called
the uplink, and the received
signal (satellite-to-transceiver) is
called the downlink.
19. BRIDGE
• A bridge is a type of
computer network device
that provides
interconnection with other
bridge networks that use
the same protocol.
• Bridge devices work at the
data link layer of the Open
System Interconnect (OSI)
model, connecting two
different networks
together and providing
communication between
them.
20. BRIDGE
• Bridges are similar to
repeaters and hubs in that
they broadcast data to every
node.
• bridges maintain the media
access control (MAC) address
table as soon as they discover
new segments,
• so subsequent
transmissions are sent to
only to the desired
recipient.
• Bridges are also known as
Layer 2 switches.
21. BRIDGE
• A network bridge device is
primarily used in local area
networks
• because they can potentially
flood and clog a large network
thanks to their ability to
broadcast data to all the nodes if
they don’t know the destination
node's MAC address.
22. BRIDGE
• A bridge uses a
database to
ascertain where to
pass, transmit or
discard the data
frame.
23. BRIDGE
• 1. If the frame received by
the bridge is meant for a
segment that resides on the
same host network, it will
pass the frame to that node
and the receiving bridge will
then discard it.
• If the bridge receives a
frame whose node MAC
address is of the connected
network, it will forward the
frame toward it.
25. ROUTER
• A router is hardware device
designed to receive, analyze
and move incoming packets
to another network.
• It may also be used to convert
the packets to another
network interface, drop them,
and perform other actions
relating to a network.
• A router has a lot more
capabilities than other
network devices,
• such as a hub or a switch
that are only able to
perform basic network
functions.
26. ROUTER
• For example, a hub is often
used to transfer data
between computers or
network devices, but does
not analyze or do anything
with the data it is
transferring.
27. ROUTER
• By contrast, routers can
analyze the data being sent
over a network, change
how it is packaged, and
send it to another network
or over a different network.
29. FIREWALL
• A firewall is a network
security system, either
hardware- or software-
based, that controls
incoming and outgoing
network traffic based on a
set of rules.
It is acting as a barrier
between a trusted
network and other
untrusted networks
such as the Internet
30. FIREWALL
• less-trusted networks such as
a retail merchant's network
outside of a cardholder data
environment a firewall
Controls access to the
resources of a network
through a positive control
model.
31. FIREWALL
• Computer security
borrowed the term firewall
from firefighting and fire
prevention, where a
firewall is a barrier
established to prevent the
spread of fire.
32. FIREWALL
• When organizations began
moving from mainframe
computers and dumb
clients to the client-server
model, the ability to
control access to the server
became a priority.
