Network Components
& How They Work
WHAT’S A WIRELESS AP?
AND WHY DO I NEED ONE?
What Are We Learning Here?
 This PowerPoint describes the function of the
following network equipment:
Hub
Switch
Router
Bridge
Gateway
Firewall
Wireless AP
And illustrates how they work together.
Hub
 Sends data from one computer to other devices on
the network. Usually operates at Layer 1 of the OSI
model because it is a low-function machine and ties
together the devices attached to it through multiple
ports. They do not manage traffic.
 Would be used in a home network to connect
several devices through the USB ports. Cost $1025.
Switch
 A switch is an improvement on a hub and controls
traffic on the network more quickly. Most often
processes & routes data at OSI Layer 2. Plays a big
part in LANs. Switches can carry power over
Ethernet so that other devices do not need separate
power supplies.
They typically cost between
$40-$70.
Switch diagram
Router
 A router is more powerful than a hub, switch or a
bridge. They do many things but usually operate
on OSI Layer 3, working with IP addresses. At
home it connects to the modem and allows
multiple users to use the Internet at once.
Routers can cost $20-$100 and
today most are wireless.
Router diagram
Bridge
 A bridge connects 2 or more LANs. The bridge is
like a router but it does not analyze the data, so
they are faster but not as versatile as a router. They
operate at the OSI Layer 2 & might be used at home
to create a single network segment from separate
LAN segments.
They can cost $50-$100.
Windows Vista can be
used as a bridge.
Bridge diagram
Gateway
 A gateway can be, in homes, the ISP that connects
the user to the Internet. A gateway can operate at
any level and is basically a network point that acts
as an entrance to a different network. Since a
gateway can be anything from a PC, a server, a
router or other devices, prices will vary greatly.
Gateway diagram
Gateway
Firewall
 A firewall is a simple program or hardware
device that filters information coming through
the Internet to a private computer network.
The device uses a set of rules to flag incoming
harmful packets of information and filters
them out.
A corporate firewall can
cost $4000+ but for home
one can be purchased for
$100-$200.
Since a firewall can be software, this shows
what a firewall does.
Firewall diagram
Wireless AP
 And finally, the Wireless AP. This is a device
that allows wireless devices, such as an iPad
or iPod to connect to a wired network. In
home use, the wireless router is also the
wireless access point. A public application of
the WAP is a “hotspot”, which allows wireless
clients to connect to the network.
A wireless AP or wireless
router can cost $30-$200
Wireless AP diagram
Network diagram
Wireless AP
Gateway
/Bridge