1: The “F” in WiFi does not mean “Free”.

If I had a nickel for every time someone insisted that “WiFi” means “Wireles Internet, Free internet,” I’d need help lifting my huge bag of nickels.

“WiFi” is a play on the term “HiFi,” which means “High Fidelity” and applies to audio recording technology.  While some free public WiFi networks do exist, there are a large number of paid services available in coffee shops, airports, hotels and other places.

You have to pay for internet at home — is it really so unbelievable that you’d have to pay for it elsewhere?

2: The maximum reach of 802.11g WiFi is 300 feet.

That’s 300 feet outdoors, with no interference.  For indoor access points, the recognized average is 120 feet.  If you live next door to a coffee shop that provides WiFi, chances are that there’s too much steel, wood, concrete, insulation and drywall between you and the wireless router for you to get a reliable signal.

Furthermore, the wireless antenna built into your laptop is not very powerful.  You can use a utility like Netstumbler to survey the wireless networks available to you, and assess what signal strength and quality you can expect to receive from them.

Generally speaking, if you’re looking to receive WiFi in your home, you’re going to have to get a cable or DSL connection and set up a wireless router.  With the exception of a few cities that provide municipal WiFi networks, WiFi is not something that you can receive in your home from an outside source; and the municipal networks can be sketchy — I don’t recommend them.

3: Almost everything interferes with WiFi.

WiFi operates at 2.4 GHz — just like most cordless phones, Bluetooth, some RF signals, and a host of other electronic communications devices.

WiFi will go through one or two walls without much degradation, but it can be interrupted by microwaves, CRT televisions, reflective surfaces, other computers using WiFi, other WiFi signals broadcast on the same channel… the list goes on.

This shouldn’t dissuade you from using WiFi altogether!  If you have a wireless router in your house, you’ll probably get great reception from it — WiFi is primarily intended for short-range, single-building connectivity.  It is possible to stretch it farther with high-gain equipment, but that can become costly (and if you’re going to shell out the money, why not get a cable or DSL connection instead?).

4: Business Class service for your business.

There is a reason that businesses pay extra for business class service.  Business class connections come with things like guaranteed uptime and redundant circuits — ISPs prioritize outages for business class customers, and have extra measures in place to meet their needs.

Basically, you may be able to run your business on residential service or public WiFi if you require intermittent connectivity to the internet; but if the possibility of 3-5 days’ downtime would cripple your business or shut you down completely, you need business class.

5: Free WiFi in apartment complexes is worth every penny.

If you’re moving into a new apartment and the offer Free WiFi, be suspicious.  Depending on which apartment you get, the signal may not reach into your unit very well.  You may have to sit on your patio to get online.  For the amount that they add to your rent, you could probably get a DSL connection of your own.

Furthermore, even if you get a good signal and the hotspot equipment is working fine, the bandwidth available to the service is split between everybody who’s using it; and if one of your fellow tenants is downloading torrents with wild abandon, it can severely slow down your connection — or worse, the management might have opted for a low-bandwidth plan, or may be blocking some ports or services.

If you’re considering an apartment with free WiFi, at least ask questions:

• How much total bandwidth is available?
• Is there a cap on my bandwidth or usage?
• Are any sites/ports/services blocked?
• Who provides the service, and do they offer competent technical support?
• Can I opt out?

Whether you can opt out or not, you should still be able to get your own DSL or cable connection.  Make sure you know all of your options.

6: All connections are NOT created equal.

While a WiFi connection may be suitable for checking your email or looking up movie times, if you’re trying to stream HD video, be prepared for disappointment.  No WiFi provider is going to guarantee any minimum level of bandwidth or speed.

Of course, this doesn’t necessarily apply to the wireless router in your house running on your cable or DSL connection; this unobstructed, unshared signal can be just as reliable as plugging a cable directly from the modem into your computer.

7: Bandwidth vs. WiFi transfer rate

802.11g has a maximum transfer rate of 54 Mb per second.  That’s megabits, not megabytes — there are 8 bits in a byte, so wireless-G is capable of transferring up to 7 MB per second.  The newest standard, 802.11n, doubles that: 108Mb/14MB per second, under optimal conditions.

This does NOT mean that you’ll be able to download at this rate.  A standard DSL connection will run anywhere from 3-7 Mbps, so you can download from a website at almost 1MB per second (optimally).  Cable connections typically run from 5-15 Mbps, so you may be able to get close to 2MB per second from the web — assuming, of course, that the web server from which you’re downloading makes that speed available to you.

In short, a 54 Mbps WiFi connection should not lead you to believe that you can download a 1-gigabyte file in under a minute.  Remember:

1. Know the difference between bits and bytes
2. Your router’s transfer rate is limited by your connection’s bandwidth
3. Your download rate may be capped by the server providing the files

Public WiFi is great for checking your email or looking up web pages, but it’s not reliable as a constant connection.  The best description of the service you’ll get?  Results May Vary.

To understand how DNS works, you need to know one simple concept: humans like words, computers like numbers.  For example, if you type either of the following into the address bar of your web browser, you’ll get to the same place:

• 208.17.81.60
• www.salon.com

208.17.81.60 is the IP address for the online news site Salon.com.  When you type www.salon.com into your browser, the browser queries a DNS server (“do you know where this is?”).  The DNS server will either tell the browser where it is, or forward the request to another DNS server (“I dunno, go ask that guy”).  Within a few hops, your web browser will learn that “www.salon.com” means “208.17.81.60″, and bring up the page for you.

This is how sites “spider” onto the internet.  If your primary DNS server doesn’t know a particular address, it sends the request along to other DNS servers; in most cases, when the query is finally answered by a DNS server that knows what you’re looking for , the servers that sent the request along will overhear the response that your browser receives, and record the record in its own database.  This way, if anyone else asks for it, the server will be able to offer up the information without having to pass the request along.

If DNS servers didn’t operate this way, it could take a very long time for you to reach ANY websites.  Imagine what would happen if only one DNS server in the world knew how to get to Google!  You’d have to stand in a very long line to check your Gmail.

If you have a home internet connection, your ISP is providing you with a DNS server or two (or three).  Some companies provide public DNS servers — Google, for example, provides 8.8.4.4 and 8.8.8.8.  If you mysteriously find yourself able to get to some websites but not others, and you know where in your network your DHCP servers are set (usually in your router), you can try replacing your primary DNS server with a public DNS server to see if it fixes the issue.

For quick and easy DNS tests, you can go to DNSsy.com.

What is an IP Address?

An IP address is a number that networks use to identify your computer.  When you open your web browser and type in the address for a website, the network needs to know how to send the page back to you, and it uses your IP address to identify your computer.

On some networks, the administrator might assign you a static IP address — this means you always use the same address, which is specified in your computer’s settings.

Most networks, however, will assign you a dynamic IP address.  This means that when you connect to the network, it gives you an address that will usually be yours until you disconnect from the network.  Most home routers and WiFi access points that you can buy are automatically set up to use this method, using a protocol called DHCP (Dynamic Host Configuration Protocol).

(It’s not important to know anything else about DHCP… I only mention it because it may be referenced in your settings.  Just keep in mind that if your connection says that it’s Using DHCP, it is set to receive a dynamic IP address from the network.).

Note: while not exactly the same, the terms “IP Address” and “DHCP Lease” are largely interchangeable.  This isn’t very important, just a term that you might hear your tech support guy throwing around.

What’s My IP Address?

Depending on what OS (operating system) you’re using, you can find your IP address in different places:

Windows XP: Click on your Start button, then go to Control Panel and then Network Connections.  Double-click on your connection, click on the Support tab, and you’ll see your IP address.

Windows Vista: Click on your Start button, go to Control Panel, then to the Network and Sharing Center.  Click on Manage Network Connections on the left.  Double-click on your connection, click on the Details button, and look for your IPv4 address.

Windows 7: Click on your Start button, go to Control Panel, click the Network and Internet heading, then to the Network and Sharing Center. Click on Change Adapter Settings on the left. Double-click on your connection, click on the Details button, and look for your IPv4 address.

Mac OS 10.5 & 10.6: Click on your Apple menu and go to System Preferences.  Click on Network, and select the connection you’re using on the left.  Click on the Advanced button and then the TCP/IP tab to see your IPv4 and IPv6 addresses.

IPv4 vs. IPv6

IPv4 (Internet Protocol version 4) is the protocol that most of the world is currently using to obtain IP addresses.  In the near future, it will become obsolete; however, right now, it’s the only IP address that you need to worry about.

IPv6 (Internet Protocol version 6) is a new standard that allows for a much larger number of IP addresses to be concurrently active.  It is currently being used in China — the rest of the world can feel free to turn it off for now.

What Can My IP Address Tell Me?

Your IP address is made up of four octets divided by dots, such as 10.59.22.12.  If one tech was reciting that address to another, he’d say “ten dot fifty-nine dot twenty-two dot twelve.”

Maybe that’s useful knowledge… maybe not.

Here are a few tips on “reading” IP addresses:

192.168.x.x: This is the most common DHCP range handed out by commercial routers.  If you go to Best Buy and pick up a Linksys, Netgear or Belkin router, plug it into your modem and connect to it, chances are you’ll get an IP address that starts with 192.168.  If your address is in this range and the last octet isn’t a 1, you’re probably okay.

169.254.x.x: IP addresses that start with 169.254 are commonly referred to as self-assigned or auto-configuration IP addresses.  You’ll get one of these if your computer expects to receive an IP address from the network, but doesn’t.  If you’re a Windows user, you might get an error that says you have “limited or no connectivity” — any of these indicators simply means that you didn’t get an IP address from the network.

Different operating systems give you different means of rectifying this problem.  In Windows (depending on which version), you should be able to Diagnose or Repair the connection to try to get a good IP address.  If options like these fail, try unplugging your router for about 30 seconds — this is called power-cycling the router, and may help resolve mysterious problems that you can’t quite put your finger on.

x.x.x.1: In almost all cases, when the last octet in an IP address is 1, it is a gateway address.  This means it’s the address of the device on the network that gives IP addresses to everybody else.  If your computer’s address ends with 1 and you can’t get online, you most likely have a static IP address that you need to get rid of.  More on gateway addresses further down…

How Do I Change My IP Address?

This is not something you want to do unless you’re sure your IP address is causing you a problem.  If you’re currently reading this online, for example, do not change your IP address.

On the other hand, if you can’t get online, use the directions above to find your IP address.  If you think it needs to be changed, read on:

Windows XP: Click on your Start button, then go to Control Panel and then Network Connections.  Right-click on your connection and go to Properties.  Double-click on Internet Protocol (TCP/IP).

Windows Vista: Click on your Start button, go to Control Panel, then to the Network and Sharing Center.  Click on Manage Network Connections on the left.  Right-click on your connection and go to Properties.  Double-click on Internet Protocol Version 4 (TCP/IPv4).

Windows 7: Click on your Start button, go to Control Panel, click on the Network and Internet heading, then to the Network and Sharing Center.  Click on Change Adapter Settings on the left.  Right-click on your connection and go to Properties.  Double-click on Internet Protocol Version 4 (TCP/IPv4).

This is the place in all Windows operating systems where you can specify an address (if one has been given to you by the person who runs your network); however, in most cases, you’ll want to make sure you can get one from the network by selecting the radio buttons next to Obtain an IP address automatically and Obtain a DNS server address automatically.

Mac OS 10.5 & 10.6: Click on your Apple menu and go to System Preferences.  Click on Network, and select the connection you’re using on the left.  Click the Advanced button and go to the TCP/IP tab.  Next to Configure IPv4, you can set the connection to Using DHCP to automatically obtain an IP address from the network; only change this if you’re sure you should.

What’s a Gateway Address?

It can be referred to as the gateway, the default gateway, the router, or a host of other names — it’s the address of the router that gave your computer its IP address, and it almost always has a fourth octet of “1″.

Fun trick! If you type your gateway address into your web browser, you’ll probably get a login page where you can put in a username and password and configure your router!

If you’ve just plugged in a brand new router, the username and password are probably both “admin”.  I’d recommend logging into it and changing the password, if nothing else.  If you don’t do this on a wireless router, and your neighbors are bigger nerds than you, you can easily find your router hijacked for their sinister purposes.

What’s a Subnet Mask?

Pretend you never saw it.  Unless you really know what you’re doing, it’s never something that you should try to alter — and it’s definitely beyond the scope of this article.

Check back for more articles on basic networking!