Constant Slow Speeds

Before we start, we need to know how well your line is working so run a speed test.

Compare the results to the maximum speed reported by the BT Availability checker. Bear in mind that your broadband isn't going to perform any faster than your line can support, and this will be the same no matter which ISP provides broadband on your BT line.

Check your usage to make sure you haven't exceeded your monthly allowance. If you're not sure what your usage allowance is, see our product information pages.

The Expected Speeds page will give you an idea of what speeds you're likely to see before and after this happens.

If you have exceeded your allowance, your speeds will return to normal at the end of your billing month. Read about Why we use Traffic Management for more information on this.

If you haven't gone over your allowance, continue reading.

1. The BT Speedtester
2. Low IP Profile
3. Low Downstream Rate
4. Raising a Fault

1. The BT Speedtester

The next step is to run the BT Speedtester. For help using this see Using the BT Speedtester.

You'll need to run three separate tests, with at least one of these being between Midnight and 4pm.

Check the Throughput speed and Downstream rate. BT state that the following figures are acceptable for broadband connections:

These are guideline figures, so we can still investigate your problem even if your throughput is not quite as low as the rates shown above.

The Downstream Rate is the speed that your kit connects to the exchange at. Unless you are on a fixed rate product (512k 1MB or 2MB) this will always be the highest possible speed up to a maximum of 8MB. If there is a problem with your line or equipment, this can and will vary.

The IP Profile is the speed your throughput is restricted to, BT believe that this is the fastest speed that you can receive whilst also receiving a stable connection. You will never see throughput speeds higher than the IP Profile and this will never be higher than the downstream rate.

2. Low IP Profile

If the IP profile is much lower than the downstream rate, your line speed will have dipped recently. An IP profile will reduce quickly if a line becomes unstable, but will not increase until the line has been stable for at least 3 days.

Often this is a symptom of a connection problem. A dropping line will keep the IP Profile at a much lower rate than it would be usually. If this is happening then report the fault as an dropping connection problem.

If you are sure the line is not dropping then the IP profile may be stuck - report the fault to our Support Team either by calling us, or online using http://faults.plus.net/.

3. Low Downstream Rate

If your downstream rate is considerably lower than what the BT Availability checker says your line can achieve, either there's a fault on the line or something in your property is causing the problem. You'll need to check your equipment is set up and working properly.

After each check: Take another look at your downstream rate. If this has risen and remains so, your IP Profile (and actual speed) will rise to match it within the next 3 days.

If none of the following tips help then report a fault and we'll investigate.

Check your telephone line is working

Check for a dial tone on your phone. If you don't hear anything, report the problem to to BT by calling 151 or using their website.

If we are your telephone provider, check the Home Phone Troubleshooting Guide.

Check for background noise on your telephone line

If you can hear crackling, pops or whistles this might mean:

• Something on your line is causing interference (This might not have microfilters fitted properly, or maybe incompatible with broadband)
• There's a faulty microfilter on your line
• You have a telephone fault

Report the problem to to BT by calling 151 or using their website. If we are your telephone provider, check the Home Phone Troubleshooting Guide.

Check your Microfilters

Check your cables and remove extensions

Faulty cables and extensions are the cause of more problems that you'd think. You need to make sure that yours are OK by testing from your master socket.

Unplug everything from your telephone line, then connect your kit to the master socket. If you still have problems try connecting with a different microfilter.

If you find that this fixes the problem, plug things back in and check the connection after each one. You'll soon find out whats causing the problem.

Have a look at the Testing from the Master Socket guide if you're having trouble with this.

Check your modem/router

Faulty hardware is another common cause of connection problems.

Do your problems stop if you restart your kit? If so try re-installing.

Modems will need their drivers removed and re-installed. Routers should be reset to their factory settings.

The instructions should show you how to do this, if you bought your hardware from us read our Modem and Router Setup Guides for help.

If this doesn't help, try testing with a different router or modem.

4. Raising a Fault

If you've checked all of the above and you're still seeing low speeds then report the fault to our Support Team, either by calling us, or online using the Broadband Fault Checker.

For help with this see our guide on How to Raise a Fault.

This article last updated 19th September 2008