ADSL vs leased lines pro con

ADSL vs leased lines – which one is best for your business?

Discover the differences between ADSL and leased lines so you can choose the right option.

It’s an increasingly rare business that isn’t committed using the internet for its day-to-day communication via email or VoIP, accessing the web and more besides. And as businesses become more and more reliant on cloud services and data storage they’re going to need the internet more than ever before. This throws into the spotlight the need to have a reliable connection to the web and one that is geared to meeting needs of the business.

Broadband – otherwise known as ADSL – is often the option that first comes to mind when getting online, but in fact, there are a number of other alternatives on the market, with alternative technologies such as leased lines in various forms. But what’s the difference between leased line and ADSL and which is going to work best for your business? There are a number of factors at work here including the size of your organisation, how you intend using the internet, and how much you rely on it for your day-to-day operations.

Basic differences

One of the main ADSL vs leased lines distinctions is in how data from your business gets to the data centre of your service provider. A leased line connects your premises directly, whereas broadband routes the data over a public network used by lots of other people.

This means there are a number of differences in the way the circuits work which we’ll look at in more detail. Which is the best choice for your business will depend on how you use the internet and how many people work for your business, as well as where they’re located.


ADSL broadband is essentially the same internet service that you have at home. It’s a shared connection once it leaves your home or business and speeds will vary depending on the type of connection. It’s an asynchronous connection – ADSL stands for Asynchronous Digital Subscriber Line – which means that download speeds are faster than uploads. Also, because it’s shared it’s a contended link which means that at peak times performance may suffer as more people are using the connection. On the plus side, it’s readily available almost anywhere in the UK and it comes at a lower price than a leased line.

Broadband may seem to be a uniform offering, but in fact, broadband connections differ due to the fact that the ADSL vs leased lines speed checkerservice can be delivered in different ways. Conventional broadband as it was first introduced in the late 1990s uses the copper telephone connections from the exchange to your location and therefore delivers the slowest speeds. It’s affected by distance, so the further you are from the local telephone exchange, the slower the connection will be. Nowadays most areas of the UK have access to fibre optic broadband but this too isn’t always the same, it comes in two main types.

Most common is fibre to the cabinet (FTTC) where the fibre terminates at a street cabinet and the final stretch to your premises is carried over the existing copper phone cables. This is faster than all-copper broadband – with typical speeds around 20 Mbps or higher – but the performance will be affected by where you are in relation to the cabinet and therefore how much copper cable is involved, although the effect will be less than on an all-copper circuit.

For those in areas where broadband via a phone line isn’t available, or is very slow, there are other options such as using the 3G or 4G mobile network or via satellite.

Leased lines

So, how do ADSL vs leased lines differ? A leased line is a connection that you rent for your exclusive use. As such, it offers a direct link from your premises to the data centre of your service provider. This is usually via a fibre optic connection, either direct or via Ethernet over Fibre To The Cabinet (EoFTTC) but can also use technology such as Ethernet First Mile (EFM) carried over copper cables.

The big advantage of leased line over broadband is that it’s synchronous, so you can have the same speed in both directions. Because it’s your exclusive circuit there is also no contention from other businesses or individuals using the link, so it performance levels will remain the same at all times. There are also no limits on the amount of data you can transfer.

Leased line connections cost more than broadband, but for most people, the extra cost will be outweighed by the fact that leased lines come with robust SLAs and that the leased line speed is guaranteed and uncontended. Leased lines have longer lead times for installation than ADSL, so if you are moving to a new site or opening a new office you need to plan your needs in advance.

Service considerations

The key consideration when weighing ADSL vs leased lines is how your business uses the web. If your internet usage is mainly sending email, accessing the web and the odd bit of cloud storage for backups, then an ADSL connection may well be all you need.

However, if you operate outside of normal office hours you’re likely to suffer from contention due to lots of other people accessing streaming services in the evening. This can happen at other times too of course, even during the day if you’re in an area with lots of other businesses all accessing the internet at once.

ADSL vs leased lines SLAWhere the advantage of leased lines really comes into its own is in the more intensive use of the internet for business. If you’re heavily reliant on cloud services for business systems – services such as Google Docs or Office 360 – then the guaranteed speed you get from a leased line connection can help things run smoothly.

Services needing high bandwidth, for example, video conferencing or VoIP calling, will also benefit from using a leased line. You also need to think about how you use data. If you regularly need to upload large files – archive documents, designs, contracts, etc – then there’s benefit to having a synchronous connection that offers equal upload and download speeds.

If you are sharing information on a regular basis with customers and suppliers as part of an integrated supply chain project, then again a leased line scores over ADSL. The reliability and speed of a leased line will deliver a better quality of experience for everyone involved and improve productivity as a result.

Something you also need to consider is just how important connectivity is to your business. If you were to lose internet access for a day or just for a few hours, what effect would it have? Because leased lines are business-focused products they have service level agreements that reflect their importance.

Unlike ADSL a leased line provider should offer you a guaranteed level of uptime and also a better target fix time in the event of there being a problem. For companies that rely heavily on reliable internet access, this is a major consideration.

In looking for service providers, therefore, make sure that the service level agreement they are offering reflects the needs of your business and ensures you will get a product that meets your needs.

Look too at what skills and experience the service provider has to offer. Membership of professional bodies and accreditations from equipment and software suppliers, for example, will offer evidence that they have the skills needed to maintain a high-quality service.

At we have wholesale agreements with all the UK’s top leased line providers and our volume purchasing power enables us to offer you the best price. Check out our list of providers here.

Decision time

We’ve looked at both ADSL and leased line services and seen that each has its advantages and drawbacks. Which one is going to be the correct solution for you and your business is going to depend on your individual needs, so you need to look carefully at your requirements.

ADSL broadband is a fast connection that will be adequate for many smaller or start-up businesses, backed up by the fact that it’s also relatively cheap. On the other hand, a leased line delivers greater reliability backed by appropriate SLAs and high speeds in both directions. This makes them a good choice as a business grows larger, or where online access is increasingly critical.

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