Increase Broadband Speed Guide

How to improve broadband speed with our speed booster guide

Broadband speed guide image
With this broadband speed booster guide, you’ll discover how to improve broadband speed to get the very fastest speeds that your line is capable of. However, before embarking on improving your broadband connection, we recommend that you determine your current downlink connection speed (which will be reported by your modem).

You will be able to immediately see any improvement from our tips in the downlink connection speed, so use this measure to judge your improvement. For the purposes of optimising your broadband connection, please ignore online speeds tests, as some can be grossly inaccurate and reported speeds can vary according to the time of day. Since immediate improvements in connection speed can take some time to be observed by speed tests, please rely on the accuracy and immediacy of connection speed.

Connection speeds are the downlink and uplink rates at which your modem connects (synchronises) to the BT exchange, and are set by equipment in the exchange. You can access the connection speeds from one of your modem’s menus. As an example, the display from the Billion 7800N modem router is shown below. It shows that, at the time this image was captured, we had a connection speed of about 6.5 Mbps on the downlink and about 1 Mbps on the uplink.

Download connection speed

Summary: Our top tips to increase broadband speed

Here are our top tips to boost broadband speed, which are explained in detail below:

1. To maximise speeds, opt for a fibre broadband service (sometimes referred to as ‘superfast broadband’) if available. The availability of fibre broadband is increasing rapidly, although this may not be widely advertised in your area, and prices may be lower than you think.

2. In the absence of fibre broadband, opt for an ADSL2+ service if available to you, since ADSL2+ offers superior download and upload speeds compared with basic ADSL. Note that ADSL2+ will not necessarily be automatically provided even if available from your exchange.

3. Ensure you have an NTE5 BT master socket installed.

4. Fit a filtered faceplate, which can substantially increase broadband speeds, particularly if you have telephone extension sockets in your home.

5. Ensure that your modem is connected to your BT master socket (rather than an extension socket) using a short cable.

6. Ensure the optimum target SNR margin is used on your line, tweaking (if necessary) the target SNR margin if your modem supports this. Reducing the target SNR margin can substantially increase download speeds.

7. Optimise your WiFi and, if possible, connect your router directly to your PC or device using a fixed Ethernet cable rather than a wireless LAN connection.

8. Consider replacing your existing modem/router with a more robust model to improve speeds, such as the new Billion 7800DXL.

9. Consider a second line, which may be surprisingly affordable. Multiple lines can be bonded together to improve speeds at relatively affordable prices.

1. Opt for a fibre broadband service (sometimes referred to as ‘superfast broadband’) if available in your area

We strongly recommend that you opt for a high-speed fibre broadband service if available in your area since fibre broadband offers significantly higher download and upload speeds at a very modest price premium compared with ADSL and ADSL2+ services.

The availability of fibre broadband is expected to increase rapidly over the next 18 months, and many new fibre street cabinets (like the one shown below) are appearing across the UK.

BT fibre street cabinet

For the very latest information about fibre broadband across the UK, view our page:

Superfast broadband in the UK

Even if fibre broadband is not currently available, we recommend that you check availability on a regular basis. To do this, you can enter your postcode in the BT Openreach checker:

BT is nearing the completion of its £2.5bn commercial investment to roll out fibre broadband infrastructure to two-thirds of UK premises by spring 2014. However, to boost fibre broadband availability further, various fibre roll-out programmes are being led across the UK by local authorities (which are using a £530 million fund established by the UK Government). As a result, in some counties, fibre broadband will be available to more than 95% of premises by the end of 2015.

For some ISPs, the price premium between high-speed fibre broadband and standard ADSL broadband is small, so seize the opportunity if you can. To choose the best fibre broadband service, please read our Which Fibre ISP page.

For services based on BT’s fibre network, connection speeds are dependent upon the distance to your nearest BT fibre street cabinet, as described in our article Chart of BT FTTC (VDSL2) speed against distance from the cabinet. Users within about 300 m of the fibre cabinet can expect to achieve about the maximum possible downstream connection speed (i.e. around 80 Mbps), with an upload speed of 20 Mbps.

The chart below shows the expected connection speed of BT’s fibre broadband (FTTC) service for different distances from the street cabinet:

Graph of FTTC speed versus distance from the street cabinet

 Chart of BT FTTC speed against distance from the street cabinet

Speeds fall to about 60 Mbps when 500 m away from the street cabinet and, at 1 km, about 28 Mbps connection speed can be achieved. Many ISPs offer online checkers that provide an estimate of likely speeds. For more detailed information about high-speed fibre broadband services, visit our What is fibre broadband? FTTC and FTTP explained page.

2. In the absence of fibre broadband, opt for an ADSL2+ service if available to you (in preference to basic ADSL broadband), since ADSL2+ offers superior speeds

BT originally launched broadband services in 2000, using ADSL technology. BT claims ADSL broadband is now available at exchanges serving more than 99% of all UK homes and businesses.

In the last few years, BT has been rolling out new broadband equipment in exchanges (termed ’21CN’), which can use more modern ADSL2+ and ADSL2 modulation technology. ADSL2+ and ADSL2 are enhancements to the original ADSL modulation technology and we strongly recommend that you opt for an ADSL2+ service if it available from your exchange. BT had extended its ADSL2+ coverage to over 92% of UK premises by summer 2013.

As shown in the chart below, ADSL2+ delivers higher data rates (up to 24 Mbps) for premises relatively close to the BT exchange by utilising a greater frequency band than ADSL. Sometimes, ADSL2+ is more susceptible to noise and interference on long lines due to the fact that a greater frequency band is used. For challenging lines, a variant called ADSL2 (which uses the same frequency band as ADSL) can provide better reliability, and can be selected by the modem on ADSL2+ lines automatically or manually.

Graph of ADSL2+ and ADSL speed against distance

Chart of ADSL2/2+ and ADSL connection speed against distance from the exchange

We strongly recommend opting for an ADSL2+ service over conventional ADSL for a number of reasons:

  • it can provide superior downlink connection speeds (as shown in the speed chart above), particularly if you are located close to your exchange
  • it can deliver significantly higher upload speeds (close to 1 Mbps or above) compared with 448 kbps for conventional consumer ADSL services
  • the gap between connection (sync) speeds and actual throughput can be significantly lower
  • BT’s Digital Line Management is much better than with ADSL, being more responsive to improved line conditions.

For distances of 3 km and less from the BT exchange, ADSL2+ delivers significant improvements in downlink data rates.

The relatively low upload speed with a conventional consumer ADSL service (448 kbps) can be frustrating, making uploads of files and photographs slow. The improved upload speeds achieved by ADSL2+ (and ADSL2) are of real benefit. In many cases, at least double the upload speed is achieved. Even premises located a significant distance from the BT exchange should experience significant upload speed improvements.

Also, BT’s implementation of its ADSL2+ service avoids the substantial gap between connection speed and real throughput than can occur with its ADSL service. So, for a 5088 kbps connection speed connection, the maximum throughput would be nearly 4.5 Mbps for ADSL2+, which is about 0.5 Mbps higher than with ADSL.

Finally, BT has significantly improved its Digital Line Management for ADSL2+ services. With ADSL, if your line experiences drop-outs, your IP/bRAS Profile does not automatically increase if you re-sync at a higher speed. If your line experiences significant interference at certain times of the day, which causes your ADSL line to drop, then your modem may connect at a much lower sync speed than normal. Any drop in sync speed is quickly followed by a drop in the IP/bRAS Profile. However, if the modem then resyncs at a much higher speed, then the IP/bRAS Profile is not increased, typically for a period of 48 to 72 hours (and sometimes longer). With an ADSL2+ service, the system responds far more quickly to changes (particularly improvements) in line conditions to ensure that the highest throughputs are being achieved.

There is much misinformation on the Internet about ADSL2+, and some even recommend NOT opting for an ADSL2+ connection if you have a long line as it can potentially result in line instability. This recommendation is fundamentally flawed. Whatever type of line you have, opting for an ADSL2+ service is always the best option. Firstly, uplink speeds are substantially improved. Secondly, the difference between throughput speed and connection (sync) speed is minimised, meaning that you would achieve higher throughputs even for the same connection speed. Thirdly, it is easy to configure a modem to use any of the available transmission modes on an ADSL2+ connection, which include ADSL2 and basic ADSL (also known as G.DMT). We recommend trying all the different modes available to ascertain which one delivers the best combination of connection speed and reliability.

It is important to note that, despite the fact that you may be connected to an ADSL2-enabled exchange, you may still have an ADSL connection. Indeed, we understand that BT may provide ADSL connections to new BT Broadband customers in ADSL2+ enabled exchanges if predicted download speeds are below 8 Mbps. It is, therefore, important to contact your ISP to request an upgrade. This can be very challenging for BT Broadband customers using traditional telephone customer support, as many customer service representatives will not understand what you are talking about! We recommend that BT customers make a request via the BTCare Community Forum (link below), which is the most effective way to be upgraded.

3. Ensure you have an NTE5 BT master socket

Image of the BTE5 mastersocket

For ADSL and ADSL2+ services, check that BT has previously installed an NTE5 master socket in your property, like the one shown in the image on the left. BT-installed NTE5s have a little BT logo in the top left of the unit. The NTE5 marks the point at which BT’s telephone cable enters your property. BT Openreach has total responsibility for the telephone network to your property and your NTE5. However, the wiring going from the NTE5 into your property is your responsibility.

Consumers are not permitted to tamper with the core part of the NTE5. However, you are perfectly free to unscrew the faceplate (the front bottom part of the NTE5), for example, to connect extension wiring. Possessing an NTE5 allows you to replace the existing faceplate with a special filtered faceplate (described below). BT has been installing NTE5s for many years, although some older houses may not have one. In the unlikely event that you do not currently have an NTE5 installed, you can ask BT to install one for you. BT may charge you for this. A cheaper alternative is to fit your own NTE5-style box next to the BT master socket as an extension.

With fibre broadband services, a master socket (with filtered faceplate) will be installed as part of the installation service, if a master socket has not previously been installed (unless you have opted for a self-install option).

4. Fit a filtered faceplate, which can substantially increase broadband speeds, particularly if you have telephone extension sockets

If you make only one tweak, please may it be this for an ADSL or ADSL2+ service! Simply remove the standard faceplate on the NTE5 BT master socket and replace it with a filtered faceplate. In most cases, this makes a dramatic difference and it’s cheap! This is probably one of the biggest secrets in the broadband industry.

As described in our ADSL faceplate page, there is substantial evidence that shows that filtered faceplates can dramatically increase broadband speeds, and yet the vast majority of consumers are not aware of their benefits and do not use them.

Filtered faceplates are automatically fitted as part of the installation of fibre broadband (unless a self install option has been chosen).

When most people set up their broadband, they go round their house and plug in micro-filters (which were provided with the modem or by the ISP) in all phone extension sockets as well as the BT master socket. Doing this can involve a significant number of broadband filters (which can look unsightly), and it is essential that there is a filter plugged in to every single phone socket, including the one used for Sky’s Digibox (if you have one). You don’t need to do this, and there is a better, cheaper solution.

All you need to do is unscrew the standard faceplate on the BT master socket, and fit a filtered faceplate. This simply fits over your BT socket. It is totally legal and supported by BT.

All this device does is separate your broadband signal from the rest of your house telephone wiring, reducing interference and noise.

An extra benefit of this faceplate is that, since ADSL filtering is now taking place at the BT mastersocket, there’s absolutely no need to put any filters on your telephone sockets throughout your property, providing a truly elegant solution.

To make it easy for you, you can buy a high quality ADSL faceplate through Amazon on the left at a low price.

5. Ensure that your modem is connected to your BT master socket (rather than an extension socket) using a short cable

Ideally, you should place your modem next to your BT master socket, wherever your master socket  is located in your property, and connect your modem to the master socket using a short cable.

We have seen many interesting wiring set-ups in homes! Please resist the temptation of connecting your modem to an extension socket rather than the main BT master socket, or connecting your modem to the BT master socket using a long extension cable.These may significantly reduce your broadband speeds, and make your connection more susceptible to noise and interference.

If you really want to locate your PC in a different room to the BT master socket, we strongly advise that you use a high-quality wireless (WiFi) router/ modem and connect your PC wirelessly so that the modem can remain next to the master socket. This arrangement will maximise your broadband speed.

6. Ensure the optimum target SNR margin is used on your line, tweaking the target SNR margin if your modem supports this

The target SNR margin set on a broadband connection (by the BT exchange equipment) has a significant impact on download connection speed, as described in our target SNR margin tweaking page. The greater the target SNR margin, the lower the download connection speed. In most cases, a broadband connection can work well with an SNR margin of 3 dB.

When a broadband connection is first made live, a default target SNR margin is set. For a BT-based broadband service, this is 6 dB. When a broadband connection with TalkTalk first goes live, a 9 dB default target SNR margin is set. Users migrating from BT-based services to TalkTalk LLU services should be aware of this since initial download speeds may be slower since the default target is higher than BT-based ADSL services (6 dB).

We believe the initial default target SNR margin with TalkTalk services (9 dB) is too high. The good news is that it is possible to get TalkTalk to reduce the target SNR margin from 9 dB to 6 dB by making a request to decrease the target SNR margin on the TalkTalk Members Forum.

Intended to help maintain a stable connection, Digital Line Management continuously monitors a connection. For a number of reasons (such as line drops due to thunderstorms or increased errors on the line due to radio interference), the exchange equipment can increase the target SNR margin. As the target SNR margin is raised, so downlink connection speeds are substantially reduced.

In some situations, the target SNR margin can be increased up to 18 dB, which can have a dramatic negative impact on download speeds.

BT Broadband users generally cannot get the target SNR margin changed, which can be particularly frustrating if the target has increased to relatively high levels. Users of BT-based broadband services will also struggle to get their target SNR margin changed since BT is resistant to doing this for other ISPs.

Rather than putting up with the target SNR margin that the BT exchange equipment sets for your line, some modems allow you to tweak the target SNR margin setting to a lower value and, hence, substantially increase downlink connection speeds.

Tweaking of your target SNR margin is covered in more detail in our dedicated SNR margin tweaking page. All modems are different, and many modems do not allow you to change the target SNR margin. If you are considering the purchase of a new modem, we would recommend that you purchase one that has the ability to adjust target SNR margin. Our favourite modem with advanced target SNR margin adjustment capability is the Billion 7800DXL. For more information, visit our Billion 7800DXL review and guide (for full information on how to tweak the target SNR margin).

Bear in mind that reducing the target SNR margin on some lines may cause the broadband signal to drop more often, so you have to balance the increased speed with reliability. For many, the compromise may be perfectly acceptable and the line may not drop, even with low SNR margin, for weeks or indeed months.

We are fans of target SNR margin tweaking, as it can make a huge difference to downlink speeds. Many broadband users find that a high-quality modem can hold its connection for several weeks at a time with an SNR margin of about 3 dB. However, bear in mind that your line may be different. If you find that your line becomes unstable at low target SNR margins, you can simply increase the target until it becomes stable.

7. Optimise your WiFi and, if possible, connect your router directly to your PC using a fixed Ethernet cable rather than using WiFi

While many broadband users may feel that they have an issue with their actual broadband connection, many performance problems are actually caused by WiFi set-up issues. Wireless connections can be extremely useful to bring Internet connectivity to mobile devices, such as mobile phones and iPads. However, wireless connectivity can potentially degrade Internet connectivity, particularly if a device is not located very close to the wireless router or if there is wireless interference.

To help you, we have developed a separate WiFi optimisation guide:

WiFi Optimisation – a guide to optimise your WiFi

If you have the opportunity, and your particular computer or device has a fixed location, we strongly recommend connecting your device directly to your router via an Ethernet cable.

8. Consider replacing your existing modem-router with a more robust model to improve speeds

When most people purchase their broadband modem router, they probably think that all modems perform in a similar fashion, and that the differences between them come down to aesthetics, features (for example, whether or not WiFi is supported) and price. However, we have found that this is not the case.

We have rigorously tested many different broadband modems over the years, and we are often surprised by how different they are in terms of the speeds that they connect at and, in particular, their abilities to maintain their broadband connections. If your modem is relatively old, or you suffer from regular disconnections on your line, there may be significant benefits in upgrading, particularly if your current modem does not support target SNR margin tweaking.

We are often asked to provide a recommendation for a broadband modem. Currently, our recommended router modem for ADSL/ADSL2+ connections is the new Billion BiPAC 7800DXL. It has a strong set of features, is very reliable (maintaining connections on poor lines) and enables the target SNR margin (discussed above) to be tweaked. Although the Billion 7800DXL is not the cheapest modem around, its feature set and great performance, even on the most challenging lines, make it excellent value for money.

9. Consider a second line, which may be surprisingly affordable

When you have applied all the previous broadband speed enhancement techniques to a single ADSL line, you could consider getting an extra line. With the increasing availability of Local Loop Unbundled (LLU) services (e.g. TalkTalk), using more than a single ADSL connection is now affordable with the right choice of supplier. Not only can multiple connections speed up Internet access, it can provide much-valued resilience – so that you are not disconnected from the Internet if a single line goes down (which is particularly important for businesses).

With the increased availability of low-cost LLU services, the cost of two ADSL connections may be little different from maintaining a single line with some suppliers. By using more than one ADSL line, you have the option of using lower-priced ADSL connections with smaller usage allowances (by spreading usage across multiple connections).

For more information, please read our dedicated Multiple ADSL Connections to Increase Broadband Speed page. With ADSL bonding services available from companies such as Evolving Networks, you can easily aggregate bandwidth (download and upload) from multiple ADSL lines from any ISP.