01/07/2020
Are you having issues with your broadband?
Before calling your ISP, be forewarned and forearmed with some useful statistics that could help your case:
1) Connection Speed/Data Rate - with most home connections (ADSL and VDSL/Fibre) you will get 2 speeds - upload and download. Download will be usually higher than upload by a significant amount. Check what package you're on and ensure you're getting something near what is advertised. Remember that your distance from the exchange and street cabinet can affect your connection speed as resistance and noise is introduced in to your line.
2) SNR Margin - This is the Signal to Noise ratio. This means how audible the broadband signal is to your modem over line noise. The noisier your line, the more errors you will have and the slower your modem/router will connect. You should use the following lookup to see how strong your signal is over the line noise:
6dB or below SNR is bad, you will experience no sync, or intermittent disconnections
7dB-10dB is fair but does not leave much room for variation in conditions
11dB-20dB is good with little or no sync problems (if no large variation)
20dB-28dB is excellent
29dB or above is outstanding. If you get this - congratulations, you probably live next door to the exchange or cabinet!
3) Line attenuation: The higher the value of this, the more signal has been lost from the exchange to your modem/router. The graph on this page - https://www.increasebroadbandspeed.co.uk/graph-ADSL-speed-versus-line-loss-distance - will give you an idea what to expect based on your distance from the exchange. Rememember this is cable distance, not "as the crow flies" so the further you are from the exchange the higher the line length will be, and it'll be more so due to the twists and turns the cable may have to take to reach you.
4) FEC/CRC - These are counters for Error Correction - if you have a bad line, this will rise as time progresses. If the number is particularly high, and your SNR is below 10, you have a very noisy connection.
"My numbers look bad - what can I do?"
If you have an old analogue land line phone in the house/garage, go get it! Unplug everything from your phone lines including routers, sky boxes, extension phones, DSL filters. Then remove the faceplate from your phone socket. If you have a newer one you'll see another phone socket toward the bottom right. Plug your analogue phone in there, lift the receiver and listen. You will hear a dial tone. This should be audible and clear. If it isn't and it sounds like someone is frying bacon on the line, you have a noise issue and will need to get BT Openreach to investigate. Most ISPs b**g the phone line in with their package, so it's up to them to engage Openreach, not you.
Report the fault to your ISP and explain you have a noisy line, and give them your SnR and attenuation figures as well. Sadly most ISP helpdesks follow a script and won't care what diagnostics you've done and will ask you to reboot PCs/laptops/routers etc. and verify all cabling before they'll even entertain the idea of a fault on the line as Openreach charge for visits should the fault be on the customer premises and not outside.
If you don't hear a noise on your line, but your connection is still bad, consider replacing the DSL filter that your router/modem plugs in to. These can fail over time as the capacitors inside them that smooth the signals age and degrade.
If you are not comfortable with doing these checks yourself, let me know and I can come to your house/site and do a basic broadband diagnostic for you for £25 (£30 if more than 5 miles from Needham Market)
