Intermittent Slow Speeds

Intermittent faults can be hard to track down; in the case of speed there are a number of possible causes.

1. Exchange Contention
2. Traffic Management
3. Interference or equipment problems
4. Slow Speeds when using a specific program

1. Exchange Contention

If your telephone exchange is busy or has a lot of heavy broadband users, your broadband may be slower than it is usually. You can check your exchange status at the PlusNet Usertools site. If the exchange checker shows your VP (Virtual Paths) status as 'Red' then you might see slower speeds, particularly at peak times. If this is the case then BT will already be aware of the problem and they'll be planning to fix it.

2. Traffic Management

We prioritise all traffic on our network, based on the type of traffic, the time of day and the type of account. Read about Why we use Traffic Management to find out more.

This shouldn't cause any serious problems. Our Expected Speeds page will give you an idea of what speeds you're likely to see at different times of the day.

3. Interference or equipment problems

With speed faults it's important to be sure that your equipment and telephone line are set up and working properly. It's harder with intermittent problems but try and test things when the problem is happening

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

Please Note: As you are looking for an intermittent problem, check your phone line at the same time the broadband problems appear.

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 computer

Viruses and Spyware can cause your computer and connection to slow down. Free programs like AVG and Spybot will help you detect and remove these.

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. Slow Speeds when using a specific program

If you have a broadband fault it's likely that you'll see slow speeds no matter what you're doing with your connection.

If you're just getting slow speeds with one type of traffic (e.g peer-to-peer or FTP) it's unlikely that your kit or exchange is causing the problem.

It's worth checking your firewall if you use one, and making sure that the program you're trying to use has direct access to the Internet via port forwarding.

This kind of problem can also happen if you exceed your monthly usage allowance.

The View My Broadband Usage page will tell you if this has happened. Our Expected Speeds page will give you an idea of speeds you're likely to see on your line.

If you're not sure what your usage allowance is, see our product information pages.

If you have gone over 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.

This article last updated 18th September 2008