I’m amazed, every single time I ask someone if their computer is behind a router or some other network device, that the response is most of the time a “jaw-dropped-face”.
There are a lot of people who are using a network devide but simply don’t know that they are connected to it.
To make the world a better place, I’ll try to explain some available network devices.
Let’s start with just the 3 most commonly used network devices. A Modem, HUB, Switch and router.
The difference all lies within the intelligence of the device, so to speak.
A modem for starters… For those who do not use a hub, switch or router (or still don’t know what it is). There is a small device which is provided by your ISP (internet service provider) which is connected to a cable coming from your.. well.. wall actually.
There is also one cable on this device that goes to either your computer or some network device (yes yes yes.. I’ll explain in a minute)… This device is your modem. The f unction of this gizmo is to translate data coming “from the internet” in such a way that your computer can understand it.
So whenever you type in a search term on google (or whatever doubtful website you are on ;-)) the modem will eventually make sure your data is delivered and that the reply given by the website is readable for your computer (which on it’s term, makes it readable for you, in your webbrowser).
If you have internet at home, you will most likely have this device (unless you are using 3G or something like that).
Great! We can now have internet on 1 computer. The problem however is that maybe your wife of girlfriend also has a computer that she wants to connect to the internet from your place.
Only 1 cable.. but 2 computer. That’s a pickle..
Well actually it isn’t. This is where the other network devices come in. You can connect your modem to a HUB, Switch or Router. And this devices will receive the signal al spread it to all devices connected. Result: more computer now can have internet :-D.
Let me explain briefly what a HUB is. This is the least intelligent network device of the ones I will describe. This little box does following when receiving a package.
The device receives a package (this can be anything) and it sends the information to every port available on the network. This is also the disadvantage of a HUB.
Imagin that you are in a room, filled with people and only 1 person can speak at the time. It may take a while before you can finally speak.
Same is going on with a HUB, data can only be sent when the network is available. Although it can happen that 2 computers send information at the same time. This is when a collision happens (don’t worry, you’ll survive). What happens then is that both computer STOP sending information and try again in a few moments. Until they have managed to send their package.
The use of this device is easy, just plug in what you want to plug in and it will most likely work.
A switch. This device is very similar to a HUB. But this device is more “intelligent”. As I said, a HUB forwards a package to every available port on the network. A switch is capable of sending a package only to the port it is destined for. Because of this, the traffic on the network is lowered and there is less risk on collisions.
Also this device is very easy to connect. Just plug it in and that is that.
A router is the most intelligent device of the ones I mentioned. Honestly, this is also the most complex device to explain and understand.
When a package is send, the router will take a look in the routing table (a list of available routes to network destinations), determine which is the correct network address and use this path to send it’s data. This next device can also be another router. This is what happens most of the time when you are surfing the web.
Your computer connects to your router, which connects to the router of the host of the website, this router will connect you to the correct webserver (agreed, this is represented a little simplistic, but it gives you an idea).
Installing a router is (just a little) more complex in comparison with connecting a switch or HUB. Most of the time some configuration is needed, specially for wireless routers since you need to enter a wireless network passcode, etc…
If you use a network device at home it will most likely be a router.
Off you go, the world is at peace once more and you know what a network device is! How great is that…