Thanks Yarwell, I won't dig it up and insulate it then

Quick update - BT called today and have arranged an Openreach appointment for me in the next few days. Fingers-crossed they can do something but still not getting my hopes up.

@Ronski
Is it just the outer insulation that is perished or is the copper of the actual pair wires exposed? Water ingress may be an issue which (and I may be wrong) can cause noise/increased attenuation on the line. In extreme cases (such as co-ax Satellite cables) water can enter the cable at the dish end (LNB) and travel down the cable eventually damaging the receiver.

It''s an armoured cable, it has an outer layer, which if I remember correctly was like clear PVC, then the armoured metal layer. It was only the outer sheaf that was damaged, the inner cables were not exposed.

Didn't think at the time to wrap some self amalgamating tape around it.

Openreach came out to me earlier today and spent a good while looking at the issue. Engineer was great and couldn't have been more helpful, and was really keen to figure it out.

Firstly in the junction box outside my house (where the line comes from under the lawn) a join was loose and came away in his fingers as he opened the box. After repairing that the speed went up by just 2mbps, so he looked further into it.

Turns out the street cabling is Aluminum which he described as being in "degraded" condition. After testing speeds on the cable at each access grid on the route he found the speed was ~45mbps at the nearest grid to my house, which is at the end of my street (100m from my property, ~500m from the cabinet). He found a spare pair between that grid and the cab so swapped my line over, bumping the speed up to ~60mbps at that point.

Back at my house in the junction box outside the speed was down to 45mbps and inside the house 40mbps, so he swapped the cable between junction box and the NTE5, and fitted a new NTE5 into the bargain. This got the speed up to 42mbps.

Unfortunately he believed this was as high as he could get it without digging the street up, which he said he wouldn't get approval for unless there was an physical/electrical fault with the cabling, though he encouraged me to report any further speed drops He said the cable under my lawn is copper and should be ok, but to replace it would require digging the street up (regardless of whether I dug my own lawn or not). As there's no grids closer than the end of the street he couldn't say for definite what improvement could be made.

When I get chance to connect to the modem and get updated stats off I will post them for reference. Thanks to all for the great feedback and I hope all this info can help anyone else if they too suffer a similar speed drop.

It's a shame the installation cost of FTTPoD is looking to be prohibitively expensive (if/when it becomes available), as I get the feeling over time this is just going to keep happening.

Rob

It does seem ali is quite widespread as on so many speed investigations a ali pops up been to blame, and given we both had similiar veyr high QLN I now suspect I am plagued by ali as well.

Did he say that pair he swapped to is now copper? or was it still ali but just a better pair?

@Chrysalis
He didn't specify the type of pair he swapped me over to but I suspect it's just a better quality Alu wire. He was scathing of Alu cable and cited it as the cause of most problems he personally deals with, and reckoned if he could he'd get it ripped out and replaced with copper but it's too costly and wouldn't be authorised.

Here are my current line stats now I've had chance to grab them:

# xdslcmd info --stats
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 2
Max: Upstream rate = 16545 Kbps, Downstream rate = 41892 Kbps
Path: 0, Upstream rate = 16668 Kbps, Downstream rate = 43138 Kbps

Link Power State: L0
Mode: VDSL2 Annex B
VDSL2 Profile: Profile 17a
TPS-TC: PTM Mode
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 5.6 6.0
Attn(dB): 0.0 0.0
Pwr(dBm): 13.1 6.8
VDSL2 framing
Path 0
B: 239 237
M: 1 1
T: 64 64
R: 0 16
S: 0.1770 0.4543
L: 10845 4473
D: 1 1
I: 240 127
N: 240 254
Counters
Path 0
OHF: 13528820 677019
OHFErr: 678 6
RS: 0 3750881
RSCorr: 0 95
RSUnCorr: 0 0

Path 0
HEC: 514 0
OCD: 0 0
LCD: 0 0
Total Cells: 3189242717 0
Data Cells: 83684726 0
Drop Cells: 0
Bit Errors: 0 0

ES: 4900 83
SES: 56 0
UAS: 7085 7085
AS: 38475

Path 0
INP: 0.00 0.00
PER: 2.83 7.26
delay: 0.00 0.00
OR: 73.42 31.91

Bitswap: 7290 4990

Total time = 1 days 23 hours 24 min 28 sec
FEC: 0 0
CRC: 57585 0
ES: 4900 83
SES: 56 0
UAS: 7085 7085
LOS: 38 0
LOF: 39 0
Latest 15 minutes time = 9 min 28 sec
FEC: 0 0
CRC: 2 0
ES: 1 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
Previous 15 minutes time = 15 min 0 sec
FEC: 0 0
CRC: 1 0
ES: 1 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
Latest 1 day time = 23 hours 24 min 28 sec
FEC: 0 0
CRC: 4289 0
ES: 664 16
SES: 8 0
UAS: 17 17
LOS: 5 0
LOF: 5 0
Previous 1 day time = 24 hours 0 sec
FEC: 0 0
CRC: 53296 0
ES: 4236 67
SES: 48 0
UAS: 7068 7068
LOS: 33 0
LOF: 34 0
Since Link time = 10 hours 41 min 13 sec
FEC: 0 95
CRC: 678 6
ES: 236 6
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
#

And this image is the resulting graphs from the scripting tools.

It's a modest improvement but sadly as good as I'm ever going to get now, and most likely it will fall over time as the Alu degrades and even more people in my area adopt FTTC.

Rob

your QLN on D1 and D2 is noticebly lower so it looks like the pair swap got you away from some of the crosstalk. Although still some there isnt as much now.