Broadband companies have been criticised for advertising connection speeds that only a fraction of customers ever actually get. But it's not always easy for them to predict what speed an individual customer will receive. Sebastien Lahtinen from thinkbroadband explains.
Imagine you run manufacturing business that uses widgets as a component. You see an advertisement on a website from a company offering to supply 'up to 24 widgets' each month for a fee of £35 per month.
However, when your first delivery arrives you find it only includes nine widgets. On querying the error, the supplier's response is that they only ever promised 'up to' 24 widgets.
It sounds confusing, unfair and illogical. Yet this is exactly how most broadband services are sold. And the grounds for it are actually quite reasonable.
What is broadband?
Broadband describes what were considered fast internet connections at a time when slow connections were the norm. Most UK broadband is delivered using DSL technology (most commonly ADSL, which stands for asymmetric digital subscriber line). This uses old-fashioned copper telephone cables to get an internet connection into your business.
There are two main causes of slow broadband speeds and it is important to distinguish between them.
Congestion can affect all internet connections. It simply means that too many people are trying to transfer too much data at once. Like having too many cars on the roads, it leads to delays in data reaching its destination.
Each broadband supplier has to strike a balance between capacity and congestion. To keep costs down, many broadband suppliers - especially those in the price-sensitive consumer market - operate a high contention ratio. This is the number of connections being sold compared to the total available capacity.
At peak times, broadband suppliers with a high contention ratio may not be able to service all customers at full speed.
To alleviate this problem, some companies implement traffic management systems. These can differentiate between different kinds of internet traffic, ensuring that when you're using your connection for something that requires a fast response - like video calls or online gaming - you get given priority.
Many business broadband packages have a low contention ratio. However, even so, your broadband supplier can't guarantee good end-to-end performance. The internet is, essentially, a network of connected networks. Your broadband supplier only has control over their bit of it. If congestion is a problem elsewhere, they can't do anything about it.
One of the main problems with ADSL broadband is that it relies on old copper telephone lines which were never designed for digital communications.
Signals degrade as they travel along the line, meaning that the further you are from your local telephone exchange, the slower your broadband service will be. In general, if you're within 2km of the telephone exchange then you will receive the top speeds, with a sharp fall thereafter depending on the type of ADSL technology used.
The upshot of this is that ADSL broadband suppliers can't market a service with a definite speed until they know the exact telephone line on which it will be used.
Before you order, most providers will give you an estimate of the speed they expect you to achieve. Unfortunately, this can't be guaranteed either, particularly as broadband providers don't own the phone lines they use.
They have to pay Openreach (the division of BT which maintains phone lines) for access to your line - and they pay the same regardless of what speed connection your line can support.
Confusing, isn't it?
What this means for you
If you're looking to purchase an internet connection, the key consideration should be how important the connection is to your business.
These applications require a reliable internet connection, so you need to look at not only the headline speed (which, as we've established, doesn't always tell the whole story) and price, but also the level of service on offer.
If your business can't function without internet access, make sure you build some redundancy into your connection - perhaps by using more than one technology or supplier. It's also important you look at upload speeds. These are important for some applications, like VoIP, yet many connections prioritise downloads, at the expense of upload speeds.
About the author
Sebastien Lahtinen is co-founder of thinkbroadband, the UK's first community dedicated to helping users resolve broadband problems. In addition to reporting on the latest broadband news, you can run a speed test on your current service, view a broadband map showing locations of telephone exchanges, availability and speeds in your area, and check if your internet connection is ready for IPv6.