Which line ?

Apologies if this turns out to be a slightly longer post but I hope there is enough experience out there with FTTC lines to help me with this.

I currently have two BT lines and now my exchange is about to be FTTC enabled, am likely to get FTTC on one line and cancel the other.

The question is which line should I get FTTC on and/or does will it make any difference to the speed/performance I will actually get (i.e. how much does expected ADSL performance affect expected VDSL - I know one is from the cabinet and the other is from the exchange but still..)

I'm about 3.5km from the exchange and approximately 500 metres from the cabinet.


Some background on my 2 lines.

Line one currently has o2 llu broadband on it and typically syncs at 5.8-6 Mbps.

The BT checker for the line states 'your line currently supports an estimated ADSL2+ broadband line speed of 6Mbps; typically the line speed would range between 5Mbps and 7Mbps.'

When I first got 2Mbps ADSL in 1999 the line only just made it under the original 41db limit

Line two doesn't have ADSL on it now, but when it did found qualifying for 2Mbps easier.

This is illustrated by the BT checker for line 2 stating "your line currently supports an estimated ADSL2+ broadband line speed of 7.5Mbps; typically the line speed would range between 6.5Mbps and 8.5Mbps.

For both lines, the VDSL estimate is the same at around 28mb

So the question is which should I get FTTC on and will it make much difference?

Line one has been 'active' for over 30 years and line 2 for 12 years+ but the drop wire for both is the same - having been replaced when line 2 was put in. I haven't had a BT fault for quite a while but when I used too, it was always on line 1 and a problem 'between my house and the exchange'

The above seems to suggest line 2 would be the better choice but line one is my main number (and subject to a 12 month BT rolling contract).

How difficult would it be to transfer that account/telephone number to line two and (eventually) cancel the existing line 2 account? - perhaps moving that to line 1 on a temporary basis to keep my o2 account until FTTC is active?

Also, does anyone know how much difference this might actually make in terms of maximum sync speed, especially with things like vectoring coming down the road..

If they go to the same cabinet, and most likely follow the same route it makes little or no difference.

So I would just get it on the line that you want to actually retain in terms of phone number.

I'm just thinking in terms of future proofing and eventual higher speeds (and that given the difference the checkers report for ADSL speeds), its possible that the 2 lines use different cables from the telegraph pole to the cabinet.. ?

If so, I imagine its likely one is better quality/less busy and thus perhaps less chance of cross talk in future..

Do we know what 'type' (thickness etc. ) BT installed over the years and which work best for xdsl?

Also, I don't know if anyone has yet got 2 FTTC lines in the same location?

If I've understood correctly, the cable BT use from pole to house tends to come in a form with 4 wires (ie 2 pairs). When a second line is ordered, it tends to use the other pair.

That cable goes back to a DP (Distribution Point) where the various pairs are jointed into a much larger capacity cable, which then goes back to the PCP, where it would be jointed (or jumpered) to the large-capacity cable to the exchange or to the tie-cable to the fibre cabinet.

That all goes to say that both of your current lines will go back to the cabinet using (almost certainly) identical spec wires. They obvious have their own joints/jumpers, and that part can make a difference in terms of being faulty, but otherwise there should be little difference in capability.

When it comes to carrying ADSL or VDSL signals on the wire, then they can vary in terms of the crosstalk experienced, because it depends on just what neighbouring wires are encountered within the cables. VDSL2 is limited by the crosstalk with the neighbours using the system - so that might be just a case of luck for now, while the sale of fibre connections ramps up. In time, vectoring should negate this effect.

The BT checker is only an estimate, particularly of your line 2 which it has no record of recent BB history on it, so it's really only a guess.

Phone cables usually come to the house as 2 "pairs", 1 for each phone line.

In reply to a post by WWWombat:

If I've understood correctly, the cable BT use from pole to house tends to come in a form with 4 wires (ie 2 pairs). When a second line is ordered, it tends to use the other pair.

That cable goes back to a DP (Distribution Point) where the various pairs are jointed into a much larger capacity cable, which then goes back to the PCP, where it would be jointed (or jumpered) to the large-capacity cable to the exchange or to the tie-cable to the fibre cabinet.

I'm with you so far. I would need to check in daylight but I think that my current DP (the telegraph pole?) has two sets of cables running up its side from the PCP.

Hence, am just wondering what if each line is connected to a different cable back to the PCP - though as you say most of the route to the exchange will be the same - i.e. given the difference in speeds and the chances of less crosstalk in future..

I'm probably over thinking this but as this is a one off decision and the other line will be cancelled want to try and get this right in terms of futureproofing. It probably wouldn't bother me but I am 500m+ from the cab and right at the end of my local loop.. so that the checkers already assume I won't get the full 40mb let alone upto 80...

Even if its not, it seems like line 2 have better joints/jumpers for ADSL - I'm just wondering if that means its likely to do so for VDSL. Also, does anyone know what sort of impact vectoring will have on lines?

I don't know if anyone has yet ordered more than one VDSL line?