Elite Data Networks Ltd
 IT Support, Structured Cabling, CCTV, Smarthome & Access Control
home search help contact

Smart Home

21 Cromwell Avenue Billericay
Essex CM12 0AE







Slow Broadband - (Wired)

With us being Data, WiFi and telephone installers these issues come from working on “the front line”, rather than from theory.

This guide is for wired broadband, not wireless and not the broadband from cable operators (that runs over traditional phone lines, and into the existing telephone wiring in your house)

1. Your extension cabling is picking up interference.

Broadband and phone extensions only need the bare minimum of telephone wiring, just two wires, to work around your house. Years ago, in the days of dial phones, a third wire was required for extensions to ring. We often find this wire is still connected, and often several others, too. All excess telephone wiring does is collect interference like long radio aerials, which is one of the most common slow broadband speed causes. Get someone competent to disconnect them. Also, if you have some of the cheap and nasty flat “under-carpet” extension cable, throw it away. It slows broadband down. We once saw a dramatic speed increase when this was binned. In fact, most extension cables and socket adapters are likely suspects. Try and eliminate them. To see if this or your extension cabling is the problem, plug your router direct into the socket behind the master socket, (hence without extensions connected), leave for a couple of days, and see if this improves matters. If it does, then your house cabling is slowing things down.

2. Your speed is “capped” by your internet service provider (ISP)

Your provider has stopped your broadband from being faster at their end, because they don’t have the capacity on their equipment to cope with lots of fast users. Check the small print, and/or ring their customer services. If you have a near neighbour using the same provider, see if they get a faster speed than you. How do you check your speed? See www.speedtest.net and www.pingtest.net they’re safe and reliable to use, we use them all the time. Slow broadband speed causes might be nothing to do with your end at all…

3. Your provider (ISP) has a problem at their end.

Some now have their own equipment in local BT exchanges, and this can be less reliable than BT equipment. Yes, it does break down and/or occasionally do strange things which are difficult to prove. Hopefully, the provider’s web site may tell you about on-going problems. But this is not of much use of you can’t get on-line…

4. Your broadband filter is faulty/breaking down.

The plug-in dangling filters are notorious for slowing things down. I swapped one for another for one customer and got an instant leap in speed. A filtered plate which fits onto the front of your master socket is even better. We can install these, and they always make the customer happy!

5. Telephone cable - All cables are not the same.

Just because it makes a circuit and gives you a dial tone does not mean it’s suitable. Broadband pushes non-fibre technology to its limits – it needs the very best in cable.


“Stranded” cable is made up of small copper or steel strands, Broadband signals hate it. It attracts interference. It does not connect easily or reliably in professional-grade jointing devices. Burglar alarm wiring uses it extensively, but that does not have to carry ultra-rapid data signals, just simple voltage. Most professional jointing equipment uses a “punch-down” method of connection known as IDC (Insulation Displacement Connection). This only works well on solid copper cable, not stranded.


Some cheap cable is aluminium, coated with copper, and called CCA, (copper-coated aluminium). It does not carry signals as well as pure copper cable. It breaks easily, and causes infuriating, time-consuming intermittent faults. The copper rubs off at the joints, allowing corrosion to form. BT used this in their network in the 1970s during a copper shortage, and are still suffering the consequences 40 years later. Look for “CCA” on the outer sheath. It will look like copper on the outside, but the core will be a dull silver colour. Like aluminium, coated in copper, in fact.


Electrical signals on a pair of wires can “talk” to each other magnetically and slow each other down, usually when laid side by side over a distance. Professional-grade cable has a twist incorporated into each pair of cables – see our photo above. This minimises interference “crosstalk”. I have seen broadband speed increase significantly by replacement of a flat under-carpet cable. We replaced it with proper solid core twisted pair cable run along a skirting board. The speed went up right away.

6. You are a long way from the exchange.

The further you are away, the slower your broadband speed will be. Fact. If BT have started putting posters saying “fibre broadband is here” on their street cabinets, then this may improve matters, as there’s a high-speed link between the exchange and that cabinet. But, if you are miles away from even that cabinet, you are, in effect, still miles away from the vital equipment, and your broadband won’t be fast. Slow broadband speed causes are often down to where you live.

7. There is a cable fault between the exchange and you.

Your broadband flows over two copper wires half a millimetre thick, which may run through ancient water-filled manholes, up poles, through huge and damp junction boxes, etc., etc. We’re amazed that it ever works at all. If you get a cracking noise on your phone, particularly when it’s been raining, there may be a problem with your line. This may not be provable to your provider, even if they say they’ve tested the line from their end. And intermittent faults are the hardest to prove. If you’ve got a distinct noise, then it’s time to call out the provider’s engineer, as it’s their problem.

8. You’ve been turning your router on and off!

Don’t turn it off, as it needs to stay in touch with the provider’s equipment all the time to “develop it’s electronic friendship”. In staying on, it builds it’s own “profile” of speed, gradually increasing until it reaches it’s maximum possible, almost as if it is “learning” the best speed for the connection. The difference can be significant the longer it stays on. If you turn it off, it has to start all over again

9. You have a faulty/old router.

Some routers have known “issues”. Finding this out sorted a long-term problem at one premises right away. Do a search on-line using your router type and version as the search terms, and see if others have had similar problems. Your ISP should provide another one if it’s known to be unreliable. They know that, and usually there’s no quibble. Or you could buy another one yourself that is known to perform well!

10. The issue is actually with your machine, not your broadband connection.

Your PC may simply be slow for multiple reasons. Not dealt with in depth here. Try another known reliable device like a lap-top or smart phone

11. You have electrical equipment interfering with your router/cables/both.

Don’t put your router next to a washing machine/microwave/television/Christmas lights/neon lighting, etc, etc. Try plugging it directly into the master socket.

So, some trade tips we’ve learnt from dealing with the mysteries of slow broadband speed causes.




- Paxton
- Connectix

- T
- Excel
- Speedtest.net
- W
- speedtests
- LightwaveRF
Data/Power Separation

HDMI over Cat 5/6 adapters  (more)

  home · designjet repairs · structured cabling · about us · refurbished printers · links · contact