If there's someone on the planet who hasn't had trouble with their Internet connection at one time or the other I don't know who it is. So, if you're having trouble with your network connection, here are some simple tricks to find out what's what with your Internet and maybe even fix it.
Check your local network
First things first, if your Internet connection is as dead as a doornail, check your network cabling. It may seem dumb, but I can't begin to count the number of times what appeared to be a major network problem just turned out to be an unplugged network connection.
This isn't just for people who are using Cat-5 cable to hook your their networks. If your Wi-Fi Access Point (AP) or cable or DSL modem have had their power cords unplugged you're not going to connect with anything. My all time favorite failure of this sort was when a friend called with a dead network connection and it turned out the problem was he'd unplugged the AP while vacuuming and he forget to plug it back in. You should always look for the simple answers first.
Continuing to look for simple answers, if your Wi-Fi connection isn't working, check to make sure that your PC is actually trying to connect to the right AP. If your device is actually trying to hook up to your neighbor's AP you're not going to get anywhere. Also remember that if you change your AP's user authentication password, you'll need to change it on all your devices as well. I've seen people often end up getting ticked off for hours before they recall that they hadn't used a particular laptop in a couple of weeks and that in the meantime they'd changed their password.
So, what if everything is powered up and hooked together but you're still not able to get to the Internet. Well, check all the basics again. I've found over the years that the odds are you've still forgotten something really simple. Lord knows I have!
Everything looks right but you still can't get to the net? Check to see if you can connect to your AP. Most APs have a Web-based administration panel. If you can get to it, it's finally time to stop looking for local area network (LAN) problems and look to your Internet connection itself.
Checking the Internet
The next step is to see what's what with your Internet connection. I could tell you a lot of fancy things to try, but I'll make this really simple. Unplug your cable or DSL modem, whatever, wait for half-a-minute and then plug it back in. If you call your ISP, chances are ninety-nine times out of one hundred they'll you to the same thing.
Then, if you're still not on the net, you might as well grit your teeth and call your ISP. This is usually a pointless exercise, but every now and again you can get useful information. For example, it's not just you but a whole neighborhood that's having problems because a back-hoe took out a cable. And, once in a blue moon, they'll actually have a helpful suggestion. No! Really! I've seen it happen!
Let's say though that your Internet is up and running, but it's being a little flaky. Here's what you do. First, let's see if you're actually getting the bandwidth you're paying for. The best site to check on your current real speed is Speedtest. This site is run by Ookla, a network performance company. If you want to know what's really going on with your LAN, wide-area network (WAN), or virtual private network (VPN) I highly recommend their programs.
For just checking out what's what with your Internet connection, their main service is free. The Speedtest site will tell you what your ping is-the time it takes from a single packet from your network to hit a host site-and your download and upload speeds. What you want is a low ping number, less than 10ms (milliseconds) is good, and high download and upload speeds. So, let's presume it's not as fast as you were promised. Welcome to the real world. ISPs usually over-promise and under-deliver on bandwidth.
Even if you have a low ping and your bandwidth looks good your connection may still not be that good. That's because ping and bandwidth only tell part of the story. You may be losing packets or suffering from jitter. To check for these problems, use Pingtest.net. The Measurement Lab's Network Diagnostic Tool (NDT) can also be used for this.
Packet loss is just what it sounds like. Your PC is sending out packets of information to some site on the Internet... and they're not getting there. Lots of things can cause packet loss: interference, overburdened network hardware, or a bad connection.
The Internet being what it is, you'll usually see a little packet loss. Ideally, you want zero packet loss, but for ordinary Internet usage you can with 1 or 2% loss. But, if you're video-conferencing, making Voice over Internet Protocol (VoIP) calls, or playing real-time online games like World of Warcraft, then any packet loss is painful. If you're doing any of those, or seeing higher packet losses, bug your ISP.
Jitter, or more precisely Packet Delay Variation, is the difference between computer to computer delays over the network. So, for example, if you ping a site once, and it takes 1ms to report back in and then the next ping packet takes 10ms to report in, you have a lot of jitter. In short, the more jitter you have, the less stable your connection is. With older programs like e-mail and ordinary Web browsers you may never notice that your Internet is less than rock stable, but with high jitter, video, VoIP, and games will once more start misbehaving.
If the packet loss or jitter seems to be coming from inside your own network, check your connections yet again and try switching out equipment on your network to see if something on your LAN is being noisy. You can also try using the Measurement Lab's NPAD (Network Path and Application Diagnosis. The Measurement Lab says that it "prescribes corrective actions with instructions suitable for non-experts" for any problems it finds. That's not quite right. You really need to know your way around a network to get much good out of it. Still, even if you're not a network pro, it's worth trying.
Still can't find the problem? It's time to get call in a network technician to find and fix it. Anyone with a Network+ certification should do. If you know your way around a network, you can find the trouble yourself with the use of tools like WireShark.
If your connection isn't delivering the promised goods, don't jump to the conclusion that you're being ripped off. Double-check your connection. Yes, check the cables one more time. Then, try it again. Still going slow? Then, connect the PC you're using for testing directly to your modem, and try again. If your connection is now up to speed then you can safely assume you have some sort of slowdown on your LAN. If that's the case it's time to look for a technician or move to levels of network troubleshooting well beyond anything I'll be covering here today.
Checking your ISP
Let's say your Internet connection is still slow. Well, there are several other factors to continue. First, you may be doing it to yourself. For example, if you're downloading a movie from a BitTorrent site or watching a Netflix video you're already using a lot of your bandwidth.
There are also times that the Internet is slower than others. For example, thanks to the rise of Netflix on the Internet, weekday evenings most ISP connections are being strained by video delivery. Since ISPs haven't, for the most part, been building out their infrastructure to meet the demand you can expect to see prime-time slow downs increasing.
You can find out if your connection is actually capable of delivering the speed you've been sold by using the Pathload2 bandwidth program from Measurement Lab. If it turns out your connection can't actually deliver the bandwidth goods, I've talk to them about a refund or, if they're not co-operative, take it up with your Better Business Bureau.
But, there may be something else going on that's throttling your speed. Your ISP may be deliberately handicapping your bandwidth. ISPs, especially US ones, are capping your bandwidth. These caps can range from 1GB (Gigabyte) of traffic in a month to up to 250GBs. As networking expert and writer Glenn Fleishman wrote in the summer of 2011, "more than half of U.S. home broadband subscribers now have some kind of cap." Yack!
250GBs may sound like a lot and it is. It's 50 million emails (at 0.05 KB/email); 62,500 songs downloads (at 4 MB/song) or 125 standard-definition (SD) movies (at 2 GB/movie). But, once you start watching HD video, or have several family members using the net, or you're constantly working on the net it's really not that much.
Each ISP handles this in a different way. Some firms, like AT&T, charge for usage above a set amount. Others, like Comcast, with its 250 GB monthly limit, give you a warning the first time you exceed your limit, and then can cancel your service if you do it again. Some services start slowing down your service if there's a lot of demand on their part of the Internet or if you're close to your limit.
To see if this is happening to you, use the ShaperProbe aka DIffProbe test. At this time, there are versions of this available for Windows XP, Mac OS X, and Linux. Sorry, there's currently no Windows 7 version.
In addition, ISPs are slowing down specific services such as video and BitTorrent. To find out if that's what happening to you, you need to use the Glasnost tests. This is a set of Web-based tests that try to find out whether your ISP is cutting down your traffic with application-specific traffic shaping. Currently, you can test if your ISP is throttling or blocking email, HTTP or SSH transfer, Flash video, and peer-to-peer apps such as BitTorrent, eMule and Gnutella. Each test will take about 8 minutes to run.
If it turns out your problem has been that you ISP has you on a strict bandwidth diet or is mucking with your use of an Internet service you use all the time, it's time to find a new ISP. That's a business problem and not a technical one so I can't help you on that one. Good luck!