Test, fix and boost your broadband

The basics
Always check the basic stuff first. Check that all cables are securely attached. If your connection simply cuts out, disconnect the power cable from the modem or set-top box, then disconnect the power from the router if you use one (simply switching these devices off isn’t enough).

Leave each for 20 seconds, then restart the modem, followed a minute later by the router and then restart the PC. With an ADSL connection, you need to have a filter or splitter (we’ll just call them filters from now on, though they do both) on every device that’s plugged into the phone line.

That’s not just phones ­ fax machines, TV set-top boxes from Sky, burglar alarms and computer modems all need a filter. Filters can be bought very cheaply, but they can also fail and cause problems. It’s worth having a couple of spares so you can swap them if you do suffer from performance issues. Lamda-Tek sells them for around £5.

The quality of your phone wiring is important too (if you use ADSL broadband ­ this does not apply to Virgin Media customers); poor connections will introduce interference, so make sure your extensions are wired up properly using good-quality cable.

In fact, some sites recommend removing the ‘ring’ or ‘bell’ wire from your system by disconnecting it at the master socket. That’s because it’s not needed by modern phones with electronic ringers and it can act a bit like an aerial, picking up interference from devices such as central heating relays, damaged microwave ovens or flashing Christmas tree lights.

Other wires in the cables don’t pick up interference in the same way as they’re used in pairs, which helps cancel out any signals that are picked up. There’s a full guide to removing a bellwire here but read our note about the legality of changing BT wires later on.

If you have a new-style master socket, BT is planning to launch a product in September called the iPlate that’s designed to filter interference from the ring wire. It’s not yet clear if the iPlate will be sold direct or through the shops but it will fit the standard BT master socket, situated near where the main BT line enters your home, which has a horizontal split and bears a BT logo.

Having said that, if you have very old wiring at home, especially if it was installed before BT allowed people to add new sockets, the cabling might not be as resistant to interference.

Unfortunately, it’s illegal to replace this wiring yourself, and it could be a lot of work, so it’s probably not worth doing unless everything else fails to improve your broadband speed. If you’re in that situation, try plugging your broadband modem or router into the master socket rather than an extension a long way from where the phone line comes into your house.