Original subtitles

So building Anami example of a simple network consisting of two PCs at home you may have a network connecting

you to the Internet using an DSL or cable or some other type of broadband connection which allows you

from your laptop or desktop to access the internet.

You may have an idea cell Rodda connecting to a modem or directly to your Internet service provider

or ISP that router may provide wireless connectivity so that you can access the Internet from your iPad

or iPhone or a laptop anywhere in your house or it may have a wired connection where you physically

cable a PC such as a desktop into the router.

Now in its most simple terms a router essentially receives data from a PC or an iPad and then determines

which to forward it so it may receive a message from your PC on one interface and then it needs to make

a decision where am I going to send those traffic or data do I send it on to the wireless network so

that it can be sent to the laptop or do I send it onto the Internet.

Because you trying to access a web site such as Facebook does come at a very basic level.

A router or other devices such as switches simply move data or information from one thing to face to

another interface based on some kind of decision criteria in the same way as you may make decisions

every day about which way to drive or which bus route or train route to take roads make decisions based

on some kind of criteria to determine the best path to a destination.

The Internet consists of many thousands of routers that are making decisions all the time about the

best path or route to a destination.

If you were driving from San Francisco to New York you would make a decision on which way to drive.

You'd have to decide which path to take if you are driving as an example from San Francisco to San Jose.

You probably wouldn't decide to drive via New York because the distance is far greater VI in New York

than it would be simply driving from San Francisco to San Jose in the same way a router will make a

decision based on distance or what's called a cost of a route to determine the best path to a destination.

So your home network may consist simply of a router with some iPads or laptops and desktops or you may

have a large home network or work in a small business environment or Soho environment Soho small office

home office and in an environment like this you may have a router connected to a device called a switch

a switch essentially gives you multiple ports or interfaces that you can connect devices to.

So in this example we have a network printer and two PCs that are connected physically via a cable to

a switch which in turn is connected to the router.

Now in a lot of home environments the switch is built into the router so you won't have two physical

devices.

There'll be one device.

The router may provide wireless connectivity once again so that your wireless laptop or iPad can connect

to the Internet without cables.