Reducing interference on fibre connection.

Ok, so I've been reading up on interference on fibre connections that can make DLM kick in and add interleaving. I suspect thats what's happening in my situation.

So after reading up on all the available information out there would I be correct in thinking that if I;

1. Got a twisted pair RJ11 short cable and replaced the HH5 one that might improve it?

2. Get an RJ45 to RJ11 cable and replace the HH5 cable that might improve it?

3.As far as shielding from radio/electrical interference, would using something like foil around the RJ11 cable reduce the interfence felt on the cable itself?

4. Also as far as electrical interference, if I'm right in thinking most of this seems to come from the electrical circuits of the house. So if its an unstable house electric network then this might cause some interference with the router. So if I was to buy a good UPS device and plug the router in to that then surely it wouldnt matter what else was connected to the plugs in the house my RJ11 and modem would be working perfectly?

Also a question, my current RJ11, because of my other phone splitters plugged in at the master socket, the cable is sort of twisted a little bit. Will this make a difference on that RJ11 cable signal quality as I've heard that the RJ11's BT sends out is the bog standard untwisted pair?

1. Yes
2. Yes

3. As long as you're using high-quality cables, and you haven't got them running under/over a microwave, kettle, and toaster, electrical interference shouldn't be a problem. Don't run them in parallel with speaker cables connected to a powerful amp either, although again, if your RJxx cables are good quality then don't worry about average computer speaker cables dangling near them. High-quality needn't mean high-price, when it comes to cables, either; yes, they won't be the cheapest, but there are probably more gimmicky and overpriced things which are simply unnecessary in the cable world than any other. If you post what you plan to buy on here, somebody will be able to tell you if it'll do the job or not.

4. When people talk about electrical interference, it's the sort we're talking about above; as opposed to some sort of unstable supply of electricity going into your router. If that was somehow happening, it would simply cause different, far more serious problems. Either your router would keep switching off, or your supply might damage your HH's transformer... which is the last point of power conversion/supply to your HH anyway, if you know what I mean. So if your house has electrical problems of that sort, you need an electrician - if you plug a UPS into a somehow damaged/dodgily wired socket, all you'll get is a UPS which might not work properly, or worse, overheat, or you can let your imagination take things from there. In short - if you have good reason to believe that the mains supply or any sockets in your home are illegally or otherwise dodgily wired, get them fixed by an electrician. Then you can definitely stop worrying about point no. 4. If you've not got any reason to believe your house is badly wired, then you can also stop worrying.

Edited by deleted (Tue 20-Jan-15 02:26:18)

5. Most interference to an FTTC subscriber comes from crosstalk, which is the interference on your line caused by other FTTC subscribers.

As take-up increases, so does crosstalk - so noise increases in steps, but in a non-linear, non-obvious, seemingly random way. Speeds decrease in steps, in an indirect manner.

A further big decrease in speed happens when the noise causes enough errors to attract the interest of DLM.

Fix: There's nothing you can do about it, except wait for BT to deploy vectoring. In the meantime, rollout of G.INP may make the intervention of DLM less painful.

I hope so or BT will end up being a victim of their own success. The more people they get to take up FTTC the worse the service will become.

Crosstalk exists on any set of parallel cables, thats why you have twisted cabling. Unfortunately if you did that to outside cable, costs and cable width would increase which would equal cost. Its fair easier to use vectoring and other methods to reduce the crosstalk issue

I have one of those phone splitter connectors plugged in to the phone socket, which then goes upstairs on a long phone extention and also I plug in the downstairs phone in the other part of the splitter.

Could me having that splitter working cause interference with the fibre connection or are the 2 parts of the socket, fibre and phone, totally separated?

Do you mean one of these

Or is it a microfilter like this

If the later then the splitter should be OK, but they can have component failures so trying a different one.

If its the first device then if there is no additional filtering on the telephones this will cause havoc with broadband

Its the first link you posted, i.e. not the microfilter.

In the bottom part I have a big phone extension plugged in to it that goes upstairs. I think its only being used on one phone now (but I'm intending to unplug that lead totally). In the top part of the splitter I have an unfiltered regular phone downstairs.

It's one of these that it is all plugged in to: http://www.run-it-direct.co.uk/btvdslfaceplate.html I was lucky to get a good openreach engineer fit that in a month before I got the infinity. So the phone splitter is in the bottom part and currently the rj11 to the HH5 is going in the top part.

I'm intending soon to upgrade the rj11 to rj45, and remove the entensions. So I'm wondering the extensions could be causing the interference. It sounds like it could be?

Okay so since the phone splitter is already in a filtered socket then it should not cause any major issues. This is the main purpose of that style of faceplate to avoid people having to rewire their home.

RJ11 is just the name of the plugs, presume you are talking about upgrading the wiring itself.