The truth about broadband

Posted on 20 Oct 2008 at 10:39

• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 
• 

 1 of 16

Gallery

For various technical reasons, it's more efficient to allocate bandwidth asymmetrically, with downstream getting much more than upstream - hence the familiar term 'ADSL', for 'asymmetric digital subscriber line'. As luck would have it, there's also a good marketing reason for ISPs to set things up this way. High download speeds suit consumers, who spend most of their time fetching content (such as web pages, music and movies) from remote servers, but aren't so bothered about upstream performance, since they'll only upload a few photos or send a few emails a day.

Business users, on the other hand, may need to send just as much information as they receive. ISPs can sell them symmetric connections at higher prices, even though they're not technically superior, just arranged differently.

So there's no such thing as the speed you 'ought to be getting', and nor can any ISP write that figure on a billboard or fix it into their standard contract, because nobody knows what speed your particular line can support until they test it. Even then, it can vary from time to time. Hence all that frustratingly vague 'up to' stuff.

Testing, testing

There is, in practice, a maximum speed for your line, and it should in theory be much the same whichever ISP you choose, since most of the infrastructure that connects you to the Internet is usually beyond the ISP's control - in much the same way that when you choose to buy your electricity from Scottish Power, it doesn't mean they get on a bus from Glasgow and start fiddling with your sockets.

It's actually quite easy to find out what speed your line should manage. Point your web browser to www.adslchecker.bt.com/pls/adsl and type in your phone number. The figure that comes back should be a reasonably accurate indication of the speed you could get. If you don't already have broadband on this line, it's a good way to find out if it's worth getting; if you do, and you're seeing speeds well below the figure given, something is probably amiss. As a rule of thumb, less than 2Mbit/sec means you're too far from the exchange to get decent ADSL performance.

All this is not to say your ISP plays no part in determining the performance you get. It's up to each provider what services they buy from BT and how they use them to fulfil their customers' broadband requirements. A few ISPs, including AOL and Be, install their own equipment at exchanges so they can offer different services from BT wholesale, and thus have additional control over customers' level of service. If there was some way of assessing this part of the process, it would be possible to recommend one ISP over another on the basis of their connection speeds.

Earlier this year, in association with our sister magazine Computer Shopper, we embarked on just such an assessment. Readers were asked to log on to our website, follow a link to test their broadband speed, then tell us the results. We also asked you to rate your ISP's customer service. Amazingly, more than 22,000 of you responded, giving us enough statistical data to compare the performance of most of the UK's leading ISPs.

Reality check

The results were interesting, to say the least. Users who were paying for 8Mbit/sec, the most popular option at the moment until higher speeds become more commonplace, were actually seeing speeds averaging from 2Mbit/sec to a top end of 6.62Mbit/sec. This last figure was only achieved by Be, an ISP that operates independently of BT to offer greater speeds than would normally be available. The typical performance of an '8Mbit' broaband connection was just under 4Mbit/sec.