Helping people with computers... one answer at a time.
A home network allows you to both share a single internet connection as well as share data and devices between multiple devices. I'll review the basics components of a home network and some steps to take as your network grows.
You just bought your second computer. Perhaps you purchased a new laptop, a tablet, a new machine for your spouse, or maybe just another machine for yourself. Perhaps you just want to connect your smartphone via Wi-Fi when you're at home to reduce the usage of your mobile data plan.
You'd like to be able to connect them all to the internet and it'd also be nice to be able to share things, like printers or extra disk space, among your machines.
You, my friend, need a LAN, or Local Area Network. There are lots of ways to set one up; I'll review the basic setup for the most common case.
Already have a network, but not sure how to grow it? I'll look at that, too.
The basis of your LAN will be ethernet. The word has a very specific technical meaning, but in common use, it's simply the technology behind 99% of computer networks. Most computers now come already equipped with an ethernet adapter – it's the squarish hole that accepts what looks like an oversized North American modular phone jack.
Your broadband connection being cable, DSL, or something else will first go through some kind of device typically called a modem (again, somewhat technically inaccurate, but it's the common term). The modem's job is to convert the broadband signal to ethernet.
You'll connect that ethernet from your broadband modem to a broadband router. Routers control two important things – as the name implies, they "route" information between computers on your LAN and between those computers and the broadband connection to the internet. The other important function (if you get what's called a NAT router) is that they provide a very efficient firewall – protecting the computers on your LAN from many of the dangers of the internet. As a side effect, a NAT router allows you to share a single broadband connection among multiple computers and other networked devices.
Each of your computers will need an ethernet adapter and most will already have them. An ethernet cable will run from each computer to the router and another cable will connect the router to the modem.
Important: Some ISPs provide a combined modem/router. That means that the two separate devices – the modem and the router – are simply placed into a single box. Your external connection goes in one connection and one or more ethernet ports are provided to which you connect your devices.
Each computer connected to this network will also need to support the TCP/IP communications protocol. TCP/IP is the fundamental "language" of communication on the internet – in fact, the IP stands for "Internet Protocol." Windows includes TCP/IP support, by default.
Unfortunately, configuration specifics for your router's connection to the internet are unique to both your ISP or broadband provider and the specific model of router that you are using, so I can't cover that in detail here. You'll need to check with your ISP and your router's documentation.
As for the router's connection to your individual devices, the default configurations of both the router and most current devices will typically work.
Most laptops and portable devices (and even a few desktops) support wireless connection via a technology known as WiFi. WiFi is a short-range wireless technology that you need to provide on your LAN, if you want to be able to use it.
The most common approach lately is to simply include wireless capabilities in your network from the start by using a wireless router.
The wireless router combines the functions of two devices: the router, just as we saw before, and a wireless access point.
A wireless access point, occasionally abbreviated WAP, is simply a network device that converts the wired ethernet signals into wireless WiFi signals and vice-versa.
Wireless routers are actually more common than their wired-only counterparts in the home and small business networking market. In fact, even if you don't have a wireless device today, I typically recommend getting a wireless router anyway for future expansion.
And once again, some ISPs will provide a combined device: a wireless router modem, which includes the functions of three separate devices: the modem, the router and the wireless access point.
If you have an existing wired network using a wired-only router and you want to expand that network to include wireless, you have two options:
Replace the wired-only router with a wireless router.
Add a wireless access point to your network.
Note: Getting an additional wireless router is not on that list. You do not need two routers. If you have a router that you want to keep, you can simply add a wireless access point.
A wireless access point is simply a device that you plug into your existing router as if it were another computer. In a sense, it "represents" your wireless computers to the router.
The number of internet-connected devices that we now deal with is pretty amazing. Unfortunately, it's pushing the limits of some of our network connectivity.
Wireless is easy. A typical wireless router or router with a wireless access point can easily handle dozens of devices connected wirelessly.
Wired devices, however, present a different problem.
Many home routers – wired or wireless – come with only a limited number of connections. It's not uncommon for there to be exactly five connections: one for the internet ("WAN" or modem) and then four for networked devices.
The problem is that it's not uncommon now to want to have more than four wired devices. If all you have is a four-port router, adding that fifth device looks like a problem.
The simple solution is a switch.
A switch1 is a semi-intelligent network extender. Its job is simply to make sure that data coming in on any port is sent to the correct other port to reach its intended destination. That's really all it is. All ports on a switch are equal. In the example above, one port of the switch is connected to one of the ports on the router to which a computer might have been connected. Other computers are then connected to the switch.
Switches come in many sizes and often add much more than just a few ports. Common configurations for the home include eight or 16-port switches.
What I've described above are the common scenarios that apply to the home and small businesses.
Those are the simple cases.
Adding multiple wireless access points, extending networks over larger distances, adding additional layers of perhaps security or functionality can all add complexity.
Complexity right up to the internet itself, which (when you get right down to it) is built of not much more than the very same building blocks we've talked about here. Oh, they might be bigger, faster, and incredibly more expensive, but the concepts are basically the same.
But if all you want to to is share an internet connection with a few devices at home, in most cases, your setup can remain pretty simple.
(This is an update to an article originally published March 16, 2004.)