FTTC VDSL and long lines

Google can sometimes search and find people who are experiencing the same problem as oneself.
I found this forum post/link from a technically competent person very informative and HELPFUL:-

https://forum.zen.co.uk/forums/thread/45715.aspx

What was refreshing was the effective solution,in this similar case to mine,to a very real problem.

Except that the post has misconceptions and red herrings.

The guy mentions vectoring, and buying a modem that has a vectoring chipset. Unfortunately, while his modem might have the capability, vectoring needs to be running in the cabinet for anything to happen - the CPE only takes a very tiny part in vectoring. And even if vectoring were running, it will only have a beneficial effect when it works for *all* lines in the cabinet, not just the one.

So there is no impact from the vectoring chipset, and therefore the new modem has done nothing whatsoever to affect crosstalk.

There then follows a long description of the chase for a new modem, but the real problem was that DLM capped the line speed when the DP was faulty. The major part of the solution was in uncapping the line, not in changing the modem.

There is an outstanding question as to whether it was the new modem alone that allowed the capping to be removed, or whether the various engineers improved the drop wire sufficiently. However, from the data in the post, this isn't clear; more line statistics under different conditions would have helped.

The new modem *did* ultimately give him an extra 1Mbps, so it is certainly running better for his line conditions than the original one.

And its not rocket science that different hardware can produce difference results. The more obvious solution is to try the ECI and Huawei hardware first.

11Mbps at 1.2km still seems very slow to me? I'm at 1.1km and sync at around 29Mbps and get attainable of 26Mbps.

It's important to realise that vectoring works best on loops less than 1000ft.

Lucky you, I am 1km from my cab and I am lucky to get above 26mbps, though I do get an attainable rate of about 32mbps. Hoping one day that vectoring will come and I will get the full 40Mbps.

I assume you meant metres, rather than feet there.

In either case, Vectoring is still working out beyond 1000 metres: Alcatel's trial results out to 1300 metres.

But it is still a red herring. In the UK, vectoring is only in use in 5 or 6 trial cabinets at the moment.

No, feet (as in kft). Note that you and me are talking loop length, i.e. there and back.
There's a presentation here http://www.adtran.com/web/fileDownload/doc/31620

Loop length isn't there and back, somewhat confusingly.

That's not a long FTTC line, I've had FTTC attempted on a 4.4km to the cabinet line.
As you can imagine, it doesn't really work, 1.9Mbps sync, connection dies when pushed above 0.6Mbps.
However, under 1.5km i'd say would be grand. Go buy a Fritz!box 3390 or 7390 and play about with their loop length estimator, or speak nicely to a BTO engineer with a pretty JDSU!

We had FTTC available on our 2.8km line, estimated 8mb/s and when we had it installed struggled to get 4mb/s we had many engineers down but they could not see what was the problem and laid it down to aluminium cables. Was hoping for better performance but maybe vectoring could help us?

I believe the most cost effective way around this is having some negotiations with a neighbour who is significantly closer to the cabinet and having your telephone line moved there.
Fixed Line Broadband is so so cheap, if your able to work with the system to get a line with the best speed possible (within reason) and link your neighbour and your house via wireless, then your getting your best value for money.
Until BT deploy fibre to the pole, or more likely those mini waterproof dslams I think people with lines over 2km it will still be really slow speeds compared to everyone else (all for a similar monthly cost!).

Yeah well that would be good but the problem is we do not have line of sight to any houses that would get a decent speed.

Edited by deleted (Mon 17-Feb-14 21:17:19)

Bah, rubbish.
Thats a shame, if there was a way of keeping your vdsl2 modem as close as possible to the edge of your property (i.e. if there was a benefit over where your current master socket is).
Couple this with a Mk2 VDSL faceplate and a VDSL2 modem which can deal with long lines (and vectoring of course) then hopefully when vectoring is fully implemented you'll have the best possible speed as you can.
cheers,
flipdee

Ah yes - I've seen a few of Adtran's presentations before. Of note is that their graphs indicate that the distances quoted are for 26AWG (0.4mm), and they can be multiplied by 1.3 when wires are 24AWG (0.5mm) - which is what we tend to have on the D-side here.

In that case, I'd have to take issue with your use of the word "best" then, as IgnitionNet corrected the bit about loop distance.

Because of what vectoring achieves (ie restores speeds back to the value you'd get as a lone user of a cabinet), then it certainly achieves the highest speeds for those closest to the cabinets, and the highest gain in speed. If, by "best", you mean fastest, then you are right.

However, vectoring continues to work effectively at distances far greater than 1kft (300m), as can be seen by other graphs in the same presentation. It is still having a noticeable effect (30% uplift) out at 5kft (1500m).

There are probably more people out there with speeds in the 10-40Mbps region, who will get uplifted, than those within 300m. The way you use "best" makes it sound like it will be ineffective for those people, when that is far from the truth. To my mind, vectoring is probably more "important" for people out beyond 600m. BT seem to be treating it that way too.

That's good to hear.