For the past few months I've been finding that my internet connection at home is very flaky. This was especially noticable when playing online games. I decided that it needed fixing so I got busy trying to diagnose the issue.
There's an awful lot of information out there about this problem or that problem and everyone has a different fix, and it is pretty confusing. I therefore I'd share with you a simple troubleshooting guide that has come from my experiences.
Firstly, lets understand what is flaky about the connection. There are three usual types of flaky connection... drop, lag and bandwidth. They are all characterised differently but all down to the same basic reasons. You'll notice the problems in different ways:
- Drop - your connection to the Internet is periodically lost, and usually comes back again after time
- Lag - getting information back from the Internet is slow - typically this will affect things that need a quick response such as online gaming
- Bandwidth - downloads take a long time and streamed sound/video is jerky
Secondly, find out where your connection is dodgy. Be aware that it might be in more than one place! For the sake of this guide, let's assume you have the standard setup of a BT line, a Wireless ADSL router and a PC with a wireless device of some kind. So you actually have these many 'connections' that could go wrong, listed in order from PC to the Internet:
- Operating System -> Wireless Driver
- Wireless Driver ->Wireless Card
- Wireless Card -> Wireless Router
- Wireless Router -> Phone Socket
- Phone Socket -> Master Phone Socket
- Master Phone Socket -> ISP
- ISP -> Internet
We'll look at each in turn and see what you can do to diagnose the issue. Firstly though, lets ensure that we do have some kind of end-to-end problem and that we're not just imagining it. Best way to do this is run some ping and download tests. You can do them yourself if you like. Open a command window and use a command like:
ping www.google.com -t
On ADSL you should expect pings of around 30-100. Over that you will have a lag issue. After this test has run for a while use Ctrl-C to stop it. A short report will show your packet loss. Ideally, it should be zero percent but realistically it could be 1 percent without there being a real problem. Higher than 1% shows some kind of issue somewhere.
You can also do some downloads of files on various mirrors and see what the download rate should be. As a guide, a 1Mbit ADSL line will typically get downloads of 40-80k/s, 2Mbit around 80/160k/s and 4Mbit around 300-400k/s. Of course, this is highly dependent on the speed of the server you are downloading from! You will be able to tell pretty quickly if your download speeds are dodgy though if you never get more then 5k/s on a 4Mbit line.
As an alternative to doing these tests manually, you can use a tool to check them. I use Dan Elwell's broadband speed test, which tests lag, download speeds and packet loss:
http://www.broadbandspeedtest.net/
Once you've ascertained that you do have a problem of some kind, you need to start looking at those seven connections we mentioned earlier. Which one you look at first depends on what your setup is and how easy things are to check. For example, if it's easy to move your router around then look at physical positioning etc. first. If it's in your loft and not easy to get to, check your software first. I'll just go through this list from 1-7. Remember that after making any change, you need to run your tests again to see what difference it made, if any and also remember - you may have more than one problem!
1. Operating System -> Wireless Driver
One of the leading causes of problems with Internet connections is out-of-date or badly written device drivers for wireless cards. If you are running Vista then beware! A lot of drivers are just re-hashed XP drivers that don't work well on Vista, if at all. Best idea is to get a new wireless USB stick or PCI card and make sure it has decent Vista drivers. Otherwise, at the least make sure you have got the very latest available drivers for your wireless device and get them installed. Many wireless devices can run using their own wireless utilities or Windows built-in utility. Try both - some are better than others.
2. Wireless Driver -> Wireless Card
Maybe the driver is having problems with your wireless USB stick / PCI card because your wireless device is faulty. There's no easy way to test this, but try swapping the USB port / PCI slot and if you can get another wireless device of the same type from another PC / a friend and give that a try.
3. Wireless Card -> Wireless Router
Sometimes the problem is simply 'seeing' the router. Wireless doesn't necessarily need a clear line of sight but anything in the way will decrease the signal. If you can, put the router right next to the PC and run the tests. If the results are the same it's unlikely to be a line of sight issue.
Another problem with 'seeing' the router can be interference. There is a lot of misunderstanding about this, but all domestic digital wireless devices (DECT phones, AV senders, wifi etc.) use 2.4GHz to communicate, plus or minus a fraction. It's this plus or minus a fraction that is important. In wifi terms, these are called 'channels'. In the UK there are 13 channels numbered 1 to 13. Each uses a slightly different frequency but all around 2.4GHz. Multiple wifi access points (APs) can use any particular channel, but you may find that performance degrades - especially if their signal is nearly as strong or stronger than your own router. Note that some people talk about 'overlapping' channels. In a sense, all channels can overlap insofar that you can have more than one device on that channel. In addition, when you choose a channel you actually end up using multiple channels. It is a good idea to use a non-overlapped channel when possible but it might not make an awful lot of difference, and overlapped channels without many/any other APs on are sometimes better than crowded non-overlapped channels. In the UK, non-overlapped channels are 1,5,9 and 13. Just to make things really fun, microwaves and other devices can throw around all sorts of rogue frequences that totally mess up wireless devices.
XP and Vista don't have any easy ways of finding out what APs in the area on what channels to help you pick a free one, and trial/error takes time and isn't very reliable. Therefore, it's best to use a utility that can help. If you are running XP or Vista, you can try Inssider:
http://www.metageek.net/products/inssider
If you are only running XP, you can try the more poweful NetStumbler:
http://www.netstumbler.com/
Note that these are commonly used for wardriving (NetStumbler particularly) and so it's a good idea to be aware of the main reason for the use of the tool is before installing it - although I find it very useful purely for diagnosing problems with my own router.
4. Wireless Router -> Phone Socket
This is an easy one - check the lead from your router to your phone socket for damage. Rabbits like chewing the lead just enough that it has bad connections without actually breaking it totally! Shorter leads are usually better than long ones as well - keep the amount of copper wire between you and the Internet to an absolute minimum. If you suspect the lead, try another one. Be aware that there are several standards of leads - some straight through, some crossover. Normally a 'modem' lead will sort you though.
5. Phone Socket -> Master Phone Socket
You may not realise it, but normally BT only support a single phone socket in your house - your master phone socket. The other sockets are just extensions and you're on your own with them. Eliminate the possibility of a badly fitted or faulty phone socket by plugging straight into your main socket - normally the one downstairs. If you're adventurous, you can take the blanking plate off and plug into the test socket within, but I'm not sure what BT would have to say about that and I can't recommend it due to the risk of electrial shock or damaging the socket itself.
6. Master Phone Socket -> ISP
If you have tested everything inside your house then you need to start thinking about your connection to the ISP. Start by giving your ISP support a call and asking them to do a free check on your connection. They should be able to do this and might escalate it to BT if they think there is a problem. Typically, there might be a bad connection somewhere between you and the exchange that needs to be sorted out.
You can often do a little diagnosis yourself on your router. Many routers now report the 'attenuation' and 'signal to noise ratio' or SNR. These are topics in themselves and what the figures mean varies depending on whether you have 'classic' ADSL or ADSL MAX. You can read more about them here. These are purely information though - you cannot change these numbers yourself. They are simply telling you what your line is capable of and set up for.
7. ISP -> Internet
It is possible, although generally unlikely, that the ISP is actually having problems with their connectivity to the Internet backbone. The best way to diagnose this is to hassle them on the phone to diagnose it! Chances are that if you're having a problem, so are all their other customers and so go to the official or unofficial support forums for your ISP and see what other people are saying.
So there we are - a very quick rundown of diagnosing your Internet connectivity problems and some suggestions on how to fix them. Hope it was useful :)