 Hub
 Switch
 Router
 Bridge
 Gateway
 Firewall
 Wireless AP
 It is the dumbest and simplest
networking device of all these devices;
it is also least expensive, least
complicated, and least intelligent
networking device comparing to
router, switch , and bridge. Hub is not
very efficient device to communicate
data on the network because by
default hubs are single broadcast and
single collision domain operating in
half-duplex mode. Hub operates at the
Layer 1 of the OSI model.
Price range depends on the
size and features and is
somewhere between
$5 - $125
 All the incoming data into one
port is copied and retransmitted
out of every port to devices at the
other end. Hub doesn't perform
any filtering or redirection of data.
So, the data send to one computer
is seen by all other computers on
the network and it is up to the
receiving computer to decide if
the data is for it. If the data is not
addressed for that device, it will
immediately refuse delivery. The
intended recipient will accept the
data and process it further.
 Can temporarily replace a broken
network switch
 Can be used when performance is
not a critical factor on the network
 Can be used in a small Local Area
Network setting where there is little
need to prevent traffic conflicts
 Can be used for network extension
 Switches are essentially the same
thing as Bridges, but usually have
multiple ports and filters and
forwards packets between LAN
segments. It generally contains
more intelligence than a hub. It
operates in full-duplex mode at
Layer 2( some switches have Layer
3 functionality)
Switches can range in price
anywhere from $10 for a no-name
budget switch to well over
$10,000 for a high-end Cisco
 Received data packets are inspected by switch, determining
the source and destination device of each packet, and then
forwarded appropriately. Each node on network connected
to a switch port has a dedicated segment and the full
bandwidth all to itself. Switching allows a network to
maintain full-duplex Ethernet. Traffic flowing in each
direction has a lane to itself - it's a collision-free
 Expands network
 Use network resources more efficiently
 Isolates non-relevant traffic from each
segment, relieving congestion and
improving performance
 Separates collision domains, reducing
 Segments, restarting distance and
repeater rules
 Increases bandwidth for dedicated
workstations or servers
 Can be used in heavily loaded networks
 It is a most complicated and smartest
networking device among all the
networking devices. It isolate each
LAN into a separate subnet and
keeps data out of subnets where it
doesn't belong. A router is connected
to at least two networks, commonly
two LANs or WAN and LAN. It can
listen to the traffic on the entire
network and determine the least
congested route to its destination.
Router is considered a heart of the
network. It is a Layer 3 device
The price range for router
can be as low as $25 and as
high as several thousands
 Routers don’t just route traffic to other
networks, they learn which are the fastest
routes and use them first
 The router looks at the destination address
of each packet sent from the source location.
It checks its table to see where this address
is there and sends each packet to that address
 The router has two basic jobs:
 To make sure that information doesn't go where it's not needed so that
the volume of data doesn't clog up the network
 To make sure the information goes to where it's supposed to go
 Routers let computers to share a cable, DSL, or satellite Internet connection
 Routers generally offload burden from your computers, leaving more
performance for your applications
 Routers have filtering that stop local users — such as children — from accessing
sites you do not want them to see
 Router has built-in security features that protects you from Internet attacks
 Some routers support VPN, which allow home users to safely log into their
businesses remotely
 Routers monitor network usage, and can send email alarms when abnormal
things happen
 Many routers have wireless capability with strong WPA encryption
 Router allows for sharing network peripherals such as printers, wireless speakers,
scanner, VOIP Telephones, fax machines
 Bridge is a internetworking device that is used to link two
networks, whether they are of different types or just different
networks or to divide one network into two. Traditional bridges
support one network boundary. Bridge is a Layer 2 device.
The cost of the Bridge starts from about $20 and up
 Bridge forward data based on
the MAC address of the sending
and receiving devices; It does
not know anything about
protocols, it simply looks at the
destination of the packet before
sending. If the destination
address is not on the other side
of the bridge it will not transmit
the data; the only data that is
allowed to cross the bridge is
data that is being sent to a valid
address on the other side of the
bridge. No valid address, no
data across the bridge
 Effectively reduces bandwidth waste by controlling the
traffic flow over a LAN
 Increases the functional length of a network by connecting
individual LAN segments
 Can connect both similar and dissimilar LAN segments
 A network gateway is an
internetworking system capable of
joining together two networks that
use different base protocols. A
network gateway can be
implemented completely in
software, hardware, or as a
combination of both. On home
networks, a broadband router or
typically serves as the network
gateway. Gateways are also known
as protocol converters that can
perform at any OSI model layer.
The price range for the
Gateway is somewhere
between $50 and $2500
 Its basic function is to make
a route of the traffic from
the computer to the
internet and from the
internet to the computer
 A gateway accepts the data
packet and converts it into
acceptable protocol in
order to further send it to
 Gateways are the best option to achieve the multimedia
communications between dissimilar networks
 Gateways are also a key mechanism of any telephony
communications. Gateway is offering bridge between
telephone network and internet
 A network gateway work like a firewall and filters packets
 A gateway performs as the interface between local and
wide area protocols such as TCP/IP on the Internet
 A gateway supervises its client devices, gather their data
and execute other task
 A firewall is simply a program or
hardware device that filters the
information coming through the
Internet connection into your
private network or computer
The price varies from nothing (you can
download a free firewall for personal or
SOHO use) to a significant investment of
capital. Enterprise firewalls, typically ranging
in price from $500 to $20,000
 Firewalls allow or block network traffic between
devices based upon rules set up by the firewall
administrator. Each rule defines a specific traffic
pattern you want the firewall to detect and the
action you want the firewall to take when that
pattern is detected
Wireless AP
 A wireless access point plugs into
a hub, switch, or wired router
and can relay data between the
wireless devices (such as
computers or printers) and wired
devices on the network over an
area of several hundred to a
thousand feet which. Wireless
Access Point uses 2.4GHz or
5GHz frequency range to send
and receive data over
electromagnetic radio waves.
Wireless AP prices start
from $35 and can be as
high as $10,000
Wireless AP
 What the access point does
is to send data requests on
behalf of the wireless
devices that are connected
to it using Wi-Fi, Bluetooth
or related standards. Access
points act a lot like cellular
phone towers: you can
move from one location to
another and continue to
have wireless access to a
Wireless AP
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