BT Boost Engineer (or similar?) don't mind if chargeable

I have two FTTC lines, one Talktalk one Plusnet, on 80/20 profiles.

Current stats from PN HG612:

DSLAM/MSAN type: IFTN:0xb204 / v0xb204
Modem/router firmware: AnnexA version - A2pv6C038m.d24j
DSL mode: VDSL2 Profile 17a
Status: Showtime
Uptime: 1 day 19 hours 18 min 19 sec
Resyncs: 0 (since 28 Jul 2015 23:33:20)

Downstream Upstream
Line attenuation (dB): 21.8 0.0
Signal attenuation (dB): Not available on VDSL2
Connection speed (kbps): 49139 6264
SNR margin (dB): 6.2 6.2
Power (dBm): 12.9 3.4
Interleave depth: 1 1
INP: 0 0
G.INP: Not enabled

RSCorr/RS (%): N/A 0.0323
RSUnCorr/RS (%): N/A 0.0000
ES/hour: 0 0

Current stats from the TT router:

Line Quality

Upstream line rate (kbit/s):
6187
Downstream line rate (kbit/s):
47161
Upstream noise safety coefficient (dB):
6
Downstream noise safety coefficient (dB):
7.2
Upstream interleave depth:
1
Downstream interleave depth:
1
Line standard:
VDSL2
Upstream line attenuation (dB):
1.6
Downstream line attenuation (dB):
16.7
Upstream output power (dBm):
3.1
Downstream output power (dBm):
14.1
Channel type:
Fast
DSL up-time:
1 day 14 hours 1 minute 46 seconds

I think the lines should be capable of a little more. BT Wholesale checker:

http://i.imgur.com/mAHUH7U.png

If I could have two lines of 60mbit, even more excitingly, 16mbit up, I'd be extremely happy.

When fitting the 2nd line, the engineer was quite chatty, and told me that he feels like the issue is just that both lines are extremely old, possibly corroded, and there is a manhole (that is more than a 1 man lift) that he'd look at were he on a job where he was trying to improve the speed as there is likely water ingress there.

Now, both lines are over the bottom end of the impacted estimate (although, the uploads are both BELOW the low end of the impacted estimate) so I doubt I can talk either ISP into accepting a fault.

That said, I'd be willing to pay for BT to fix the lines up.

Is there such a service I can pay for? I feel I'd have better luck talking to PN about this tan TT, but, were I willing to pay for it, would they send an engineer on such a job, and what would be the limits of what he could do?

Oh, and disconnecting one line does not speed the other up, both have twisted pair RJ11 cables, there is no extension wiring on either line, so I don't feel there is a home wiring issue or a crosstalk between the two lines issue.

Thanks in advance!

I don't know how to get this done but the question is how much are you wiling to pay?

Depending on the issue the real cost of doing anything could be well into the thousands - especially if they end up having to clear ducts and replace lengths of line. You might be better waiting (and hoping) for BT to launch their new FTTPoD service and using that to go onto a full FTTP solution - the trouble is we don't know what the new service will look like or how much it will cost (or indeed if they will even roll it out nationwide).

Why do you think both are capable of higher speeds?

The downstream attenuation levels might suggest they are (although the TT upstream attenuation figure is almost certainly wrong) however three of the SNR figures are all around 6dB suggesting there is a significant level of noise on the line. If that is the case then there is very little BT can do - have you tried it with everything in the house turned off apart from 1 modem and a PC?

In reply to a post by MHC:

Why do you think both are capable of higher speeds?

The downstream attenuation levels might suggest they are (although the TT upstream attenuation figure is almost certainly wrong) however three of the SNR figures are all around 6dB suggesting there is a significant level of noise on the line. If that is the case then there is very little BT can do - have you tried it with everything in the house turned off apart from 1 modem and a PC?

A combination of both engineers (first FTTC engineer, then 2nd line install engineer) thinking they should perform better, and the fact that one was specifically mentioning old cable etc. My upload is below the low end of the impacted estimate for both lines, this to me says there is likely something wrong.

Old cable - unlikely to affect the line unluess there are joint issues. Older cables are often larger in diameter and will not normally add atenuation. If there are bad joints then they will increase attenuation.

At 16.5 dB you could be seeing up to 70Mbps - PROVIDED the noise levels are reasonable. Your SNRs are around 6dB which points towards high levels of noise - that is possibly what is restricting speeds. If there is a noise issue pushing down the downstream capability then there is a good chance your upstream are being compromised.

And as BOTH lines are similar then I would suggest it is unlikely that a line fault is the problem - if only one was affected then possibly but not both.


Install DSLstats and see what the Tones graphs look like - take a snapshot of each and host it somewhere and provide a link.

Bad Joints is what the 2nd engineer was talking about.

Here's some DSLstats graphs.

http://imgur.com/a/imzh1

Have a look at U2 ... It should run from around 1970 to 2700 - On my line with 16.4dB down attenuation suggesting a similar length, I am seeing 6 bits per tone up to 2250 and then 5 bits through to the end. Your U2 is barely there and has totally gone at 2350. The SNR per tone on your line at U2 is about 10dB whereas I am seeing 30dB tailing off to about 25dB - way higher.

At rough figures my U2 carries around 3x the data that U1 does. Without your U2 carrying very little data the best you will be seeing is potentially around 5-6 Mbps.


What about the second line? Are the graphs for that similar?

Very similar, yes. I don't want to plug the HG612 in to it right now for fear of upsetting DLM though!

I'm quite a way from the pole, getting the 2nd line installed involved replacement of old flat "figure 8" type cable from my roof to the two sockets with modern 4 pair cable, the cable from my roof to the pole is 2 pair, probably drop wire 10 I guess.

Part of me is tempted to order a 3rd line forcing a re-pull of the overhead cable...

Edited by nemeth782 (Wed 29-Jul-15 15:38:22)

They may not pull a new drop wire through. We have two coming to the house here rather than a single DW14. What will that change? And you could find you are too far for a four pair anyway.

As for upsetting DLM, why should it? Power off and wait before you disconnect, and limit it to a single every hour (just in case) and it should be fine. It has to be the next step - comparing the two lines with the same modem installed. That will give a lot of information.

Ok. I shouldn't need a PPPoE connection in order to get stats right?

Give me a few mins.