21CN broadband trial in my area - should I take part?

kwikbreaks

You are right to point out that the default noise margin is high at 15dB but ISPs are rarely able to get BTw to reset this and even if they do it will likely creep back up over time if the underlying problem isn't fixed.

The reason it is high is an unstable connection and the cause of that is usually that dreaded bell wire although some routers are pretty poor. The simplest solution would probably be to fit an iPlate as that requires no knowledge or skill and should result in an improvement.

With 43dB attenuation there is little chance of getting a 12Mbps sync. My own line had 35dB attenuation on ADSL and I struggle to get 12Mbps on ADSL2+ with no internal extensions at all.

One advantage of taking the trial would be that the profile would be set back to defaults (I assume) shortcutting the long wait for the default margin to revert to 6dB if the only action was fitting an iPlate.

Without some work on the internal wiring the trial would probably be more trouble than it is worth.

The other consideration is what router is being used - most will support ADSL2+ but some make a better job of it than others.

Minerva69

Many thanks for the helpful replies :beer: GunJack & kwikbreaks, I didn't know about the bell wire/iPlate, will definitely check those out, thank you. The router I have at the moment is a BT Voyager 2110, have just checked BT's website and it says it is ADSL2+ compliant, so I'm hoping it would work.

kwikbreaks

I don't know that router well but I've just checked and it uses a Broadcom chipset which are usually fine - those using the Texas Instruments AR7 are probably the worst ones.

I'm not saying the iPlate will definately fix anything but if you have telephone extensions in use and have never removed the ring wire connections or use plugin extensions it should help a lot.

You have a fairly long line so ADSL2+ isn't going to do a huge amount for you. At least you picked a decent ISP though rather than taking the cheap and not-very cheerful route.

Minerva69

I've just been reading up about the iPlate and it seems you need to have a particular type of phone socket for it to work, and I'm not sure ours would be ok as it looks quite old and it hasn't got the horizontal split that seems to be required? (sorry about the pic quality!)

Edit: I've just discovered that the iPlate won't work, BT has photos of suitable sockets on their website As our socket looks so old, I'm a bit worried about what the condition of the wiring would be if I tried to snip the bell wire.

kwikbreaks

Is that definitely the master socket? If it is then unfortunately you can't fit an iPlate.

What does the cable coming from the socket go to? - I don't see a filter unless that is the fly-lead for one. Do you actually have extensions? - if not then an iPlate wouldn't help anyway and the cause of your high target noise margin is a bit of a mystery.

Minerva69

kwikbreaks wrote: »

Is that definitely the master socket? If it is then unfortunately you can't fit an iPlate.

What does the cable coming from the socket go to? - I don't see a filter unless that is the fly-lead for one. Do you actually have extensions? - if not then an iPlate wouldn't help anyway and the cause of your high target noise margin is a bit of a mystery.

We only have one phone socket in the house and that is it, so I'm assuming it's the master socket! It's in a really awkward place at the bottom of the stairs, on an outside wall. Yes that is a lead for a filter you can see in the photo. We don't have any proper extension sockets, but our phone is actually plugged in upstairs via an extension cable, as we don't have enough power sockets to plug in a cordless phone downstairs! This house used to be owned by a DIY-er who had no idea what he was doing, lol.

espresso

Minerva69 wrote: »

We only have one phone socket in the house and that is it, so I'm assuming it's the master socket! It's in a really awkward place at the bottom of the stairs, on an outside wall. Yes that is a lead for a filter you can see in the photo. We don't have any proper extension sockets, but our phone is actually plugged in upstairs via an extension cable, as we don't have enough power sockets to plug in a cordless phone downstairs! This house used to be owned by a DIY-er who had no idea what he was doing, lol.

That would explain your slower than expected speed then.

GunJack

if you do a quiet line test, (dial 17070 and listen for any background noise) and it fails, i.e. you hear buzzing, clicks, etc, report a voice fault to bt and when they come out, they should replace that socket with an NTE5 at no cost...you may be suprised at the difference it makes....

kwikbreaks

espresso wrote: »

That would explain your slower than expected speed then.

Not if the extension plugs into the filter at the master end - that is no different from a filtered faceplate because the extension is effectively isolated from the ADSL pair.