FTTC just installed, speeds below the estimates, next steps?

So after a little negotiation with BTO and PlusNet, I am not connected to FTTC.

On ADSL I used to get connected at about 3Mb line speed. 55dB attenuation.

On VDSL I am now connected at about 1.9Mb line speed, I will show you the stats from an unlocked HG612 in a moment. Sometimes it will connect at 3.5Mb but it will not stay connected for long. Frequently the modem may sync at just 0.5 to 1.2Mb, the SNR per tone graph on dslstats shows there is periodic noise on the line.

There are 2 new BDUK funded cabinets in the village.

It is about 2km on the E-side of the cabinet and about 1.6km to my home via the road, and the phone lines mostly follow that road, if anything they take a shorter route cutting off one of the corners en-route. The JDSU used by the BTO guy also showed it was 1.6km.

So the stats from the HG612 are currently.

xdslcmd info --pbParams
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 2
Max: Upstream rate = 1061 Kbps, Downstream rate = 3164 Kbps
Path: 0, Upstream rate = 1065 Kbps, Downstream rate = 2276 Kbps

Discovery Phase (Initial) Band Plan
US: (0,95) (868,1207) (1972,2783)
DS: (32,859) (1216,1963) (2792,3959)
Medley Phase (Final) Band Plan
US: (0,95)
DS: (32,859) (1216,1963) (2792,3959)
VDSL Port Details Upstream Downstream
Attainable Net Data Rate: 1061 kbps 3164 kbps
Actual Aggregate Tx Power: 10.5 dBm 4.6 dBm
============================================================================
VDSL Band Status U0 U1 U2 U3 D1 D2 D3
Line Attenuation(dB): 16.7 N/A N/A N/A 32.4 66.4 0.1
Signal Attenuation(dB): 16.7 N/A N/A N/A 32.4 66.4 0.1
SNR Margin(dB): 6.5 N/A N/A N/A 8.9 0.0 0.0
TX Power(dBm): 10.5 N/A N/A N/A 4.6 -128.0 -128.0
#

Another person, the other side of the village (they are not an immediate neighbour) has an attenuation of 36dB and is getting about 5Mb line speed. So my D1 attenuation of 32dB is in the same kind of ball park to theirs, they claim their line is stable at 5Mb.

So thoughts on these stats please?

The estimated download speeds for me even on an impacted line were 5.1 to 2 Mb.

And how to progress with BTO to make improvements? There are few or more likely zero spare pairs in the D-side cable.

In reply to a post by godsell4:

So after a little negotiation with BTO and PlusNet, I am not connected to FTTC.

YES your are. Why do you think you are not connected to FTTC?


In answer to the attenuation question and speeds. Whilst 32 and 36 dB are not far apart in terms of line loss that is only half the story - you have to take into consideration the SNR (margin) too. If your line is picking up significantly more electronic noise on the route it takes - from other houses, factories, traffic lights, crosstalk from other users &c then then there will be less usable signal for the modem to work with, hence the lower speeds. Given their routing is probably way different to yours then it is entirely possible.

Edited by MHC (Wed 03-Jun-15 10:54:28)

In reply to a post by MHC:

Why do you think you are not connected to FTTC?

Most likely typo. The OP meant "now".

Yes I am now connected to FTTC, there was a typo in my original post.

It seems that VDSL2 aims for a target SNR value of 6dB on both the upstream and downstream connections when they go through the line training.

Despite this, my actual SNR appear to be between 9dB and 14dB whether it connects at 1Mb or 3Mb.

The routing of the other line is for sure 'different' but their line goes entirely over poles and is for sure in good condition, parts of my line are stuck in the ground and have been cut through and repaired a number of times. Also just this week BTO were working on a house near me and of course they claim the work they did had no affect on my line, I can be sure that the plost from dslstats says something very different.

So the achieved speed is less than the Impacted Range B values. Has anybody found that motivates BTO to do something?

A "perfect" type that completely reverses the meaning.

I am wondering if the SNR figures are above the 6dB margin because of the way they are calculated? A screen-shot of the bin plot using DSL Stats could be useful.

Make sure you get some screenshots of the BT DSL Checker showing the impacted figures - your actual figures will be fed back into te checker to help improve the accuracy so it is imperative to get some NOW.

When you have those you should be able to get PlusNet to persuade BT OR to investigate.

bitloading image http://postimg.org/image/8nc2vjo93/

SNRperTone1 http://postimg.org/image/6rlklnkyt/ which shows a periodic notch in the SNR plot

SNRperTone2 http://postimg.org/image/5m4n0o931/ which shows what the SNR plot looks like most of the time

Well as of this evening, I do not feel PN has really been fighting my corner here.

In fact at 16:11 PN updated my issue they have talked with BTO again and have "agreed with BTO that the line is too long to work", and they would arrange to move me back to ADSL, 10 minutes later my FTTC connection was disconnected, by BTO or PN I am not sure, but I have been left tonight without any kind of DSL ... great while I am working from home! I will be connected to ADSL again sometime tomorrow.

The most part of their message at 16:11 reads:

Thank you for your message. I called the suppliers again to ask for some further advice about how to best progress the situation and I have been advised that a team leader has been out to review the work and agrees that the line is too long to provide an effective fibre service.

They recommended that order be closed off so that we can provide ADSL services, because if the fibre is left connected it will constantly fault due to no sync and you would be left in a position of paying for a service that we cannot provide. The order will therefore be closed off in the next 48 hours so that we can regrade the service to ADSL.

I am sorry that I am not able to give a different answer, I have followed up as best I can with the suppliers to try and resolve this but the answer I am being given is that the line speeds will not improve and these are too slow to effectively sync the fibre service.

So the line stayed connected at about 2Mb all last night, the SNR plot looked pretty stable, much less noise on it than the ADSL the previous couple of nights.

The BTO speed estimator was this http://postimg.org/image/8gz3lykb3/ I am about 120-150m from the DP. At the DP, the JDSU managed a stable 8Mb.

If we assume BTO create the table based on knowledge of the line lengths and they have knowledge of what are acceptable performance for those lines, then we can say this line is of poorer quality than even BTO expect.

I can not fault the efforts of the two BTO engineers who did all they could while they were here.

We are now in the position where BDUK money has been used to build 2 new cabinets, at a cost of £15K each maybe, but due to poor line quality it is not possible to get connected according to BTO. Is this a reason why FTTC take up has been so low in some rural locations? And so making it harder for those claw back clauses to kick in?

Edited by godsell4 (Wed 03-Jun-15 22:41:43)

How often do you see that notch? That could be a local noise source.


As for BitLoading - there is certainly something odd from tones 120 to 310 where there is 10dB SNR which would normally allow 5 or 6 bits per tone. As to why there is nothing ... no idea or suggestion. The ISP needs to see and understand teh graphs - how you achivre that - it could be a long struggle,

And if Openreach have declared the line not fit for FTTC the chances of success probably zero.

Waiting to get an update from PN this morning to see if that is what has happened.

In reply to a post by MHC:

How often do you see that notch? That could be a local noise source.

As for BitLoading - there is certainly something odd from tones 120 to 310 where there is 10dB SNR which would normally allow 5 or 6 bits per tone. As to why there is nothing ... no idea or suggestion. The ISP needs to see and understand teh graphs - how you achivre that - it could be a long struggle,

I agree that notch looks strange - very straight-sided. The noise is wideband enough to affect multiple tones, but filtered enough to laser-target those tones. It is almost like it is caused by something designed to transmit in precise tones ... ie a broadband modem.

The bitloading looks right to me. The point where my modem allocates only 2 bits is around tone 310 (where the PSD mask allows transmit at the lowest power); at the same area on my SNR-per-tone graph, I'm seeing SNRs of 20-21dB. I suspect the cutoff lies in the region of 18dB.

In reply to a post by godsell4:

The BTO speed estimator was this http://postimg.org/image/8gz3lykb3/ I am about 120-150m from the DP. At the DP, the JDSU managed a stable 8Mb.

Is that 120-150m above or below ground? And how much of the distance is across land you own?

If it were all your own land, you could ask for a phone line to be installed to a service point just inside your boundary, into a sealed box (something like that is used for the initial supply to the office on building sites). You provide your own power and ethernet connection to the box from home ... a new, short drop line should improve your performance.

If we assume BTO create the table based on knowledge of the line lengths and they have knowledge of what are acceptable performance for those lines, then we can say this line is of poorer quality than even BTO expect.

As I understand it, BT's estimation tools make use of the detailed data between cabinet and DP, and then add an allowance for an assumed standard drop cable length - likely to be less than 30m. Every line on the same DP gets the same estimate.

With such a long drop line, your actual behaviour is going to be less than the estimate ... and in your case, this part looks to be poor.

I can not fault the efforts of the two BTO engineers who did all they could while they were here.

If that JDSU behaviour was indeed stable, and never notched, I'd expect the speed drop from DP to your house to be less. A couple of Mb at most.

Should the engineers have tried a new drop line?

We are now in the position where BDUK money has been used to build 2 new cabinets, at a cost of £15K each maybe, but due to poor line quality it is not possible to get connected according to BTO. Is this a reason why FTTC take up has been so low in some rural locations? And so making it harder for those claw back clauses to kick in?

The statistics related to the BDUK cabinet, and the funding allowed, will only apply to the properties that get superfast speeds. In rural areas, the cabinet is almost certain to include some lines longer than this - and the fact that these will fail is factored into the decision over whether to provision a cabinet at all.

The fact that counties only have a target of ~90% allows these failures to remain in place, for now.

Even including this factor, the take-up rates seem to be best amongst the most rural lines. An interim evaluation of Superfast North Yorkshire (a year ago) reported:

Take-up rates across cabinets range from just above zero to 35%. Emerging patterns suggest take-up rates have been markedly higher in more isolated rural areas where access to faster broadband speeds was previously low and, to a lesser degree, in more prosperous areas.

This was a third of the way through the project, when the average take-up over the county's BDUK lines was at 11%. Phase 1 is now complete, and take-up now stands at 23.5%. That will have triggered the clawback clause.

I agree that notch looks strange - very straight-sided. The noise is wideband enough to affect multiple tones, but filtered enough to laser-target those tones. It is almost like it is caused by something designed to transmit in precise tones ... ie a broadband modem.

If I get moved back to ADSL are those tone numbers in the same band used by ADSL1? I am on one of those small MarketA locations where we have never had ADSL2+. If this noise should show up on ADSL then I could progress the fault finding even if I were back to ADSL. But I hope to stay on VDSL2 if I can get that to happen via my ISP.

Is that 120-150m above or below ground? And how much of the distance is across land you own?

If it were all your own land, you could ask for a phone line to be installed ... a sealed box

From the DP the line is all above ground, but it is shared land and private land, though the owner of the private land would be approachable if that became the last resort.

Should the engineers have tried a new drop line?

I believe the wiring has not been done in the most "traditional manner" in this location, the pole which every engineer who has been here calls the DP, is certainly 120-150m away. However. From this DP it provides phone lines to a row of 4 houses, then a farm building and then a farm house.

From the DP to the 4 house, there are 2 poles placed near to the houses, each pole has a small grey box at the top of it and from each grey box it provides a drop wire to the two nearest houses. From one of the grey boxes, there is a cable which then carries on 100m to the farm building and then another 500m to the farm house.

Good Huh!

Is this acceptable wiring practice these days? Are there SIN or other documents I can reference regarding this wiring practice?

In reply to a post by godsell4:

I believe the wiring has not been done in the most "traditional manner" in this location, the pole which every engineer who has been here calls the DP, is certainly 120-150m away. However. From this DP it provides phone lines to a row of 4 houses, then a farm building and then a farm house.

From the DP to the 4 house, there are 2 poles placed near to the houses, each pole has a small grey box at the top of it and from each grey box it provides a drop wire to the two nearest houses. From one of the grey boxes, there is a cable which then carries on 100m to the farm building and then another 500m to the farm house.

So there is a pole upon which is mounted the DP. From the DP there is one (or more?) cable(s) that proceed to carrier poles, each of which is fitted with a BT66. From each BT66 there emanates the final drop cable to each relevant premises.

That reads like a fairly common rural scenario and is not abnormal.

In reply to a post by godsell4:

If I get moved back to ADSL are those tone numbers in the same band used by ADSL1? I am on one of those small MarketA locations where we have never had ADSL2+. If this noise should show up on ADSL then I could progress the fault finding even if I were back to ADSL. But I hope to stay on VDSL2 if I can get that to happen via my ISP.

Yes. ADSL and ADSL2 use tones up to 256, ADSL2+ uses tones up to 512.

I believe the wiring has not been done in the most "traditional manner" in this location, the pole which every engineer who has been here calls the DP, is certainly 120-150m away. However. From this DP it provides phone lines to a row of 4 houses, then a farm building and then a farm house.

From the DP to the 4 house, there are 2 poles placed near to the houses, each pole has a small grey box at the top of it and from each grey box it provides a drop wire to the two nearest houses. From one of the grey boxes, there is a cable which then carries on 100m to the farm building and then another 500m to the farm house.

Good Huh!

Is this acceptable wiring practice these days? Are there SIN or other documents I can reference regarding this wiring practice?

Certainly it used to be acceptable for the poles to convey more than just drop-wires direct to homes, but to have multiple carrier poles to distribute the drop wires too. I believe that was the practice, especially in rural areas, pre-70's.

Take a look at figure 3.4 in this document:
http://stakeholders.ofcom.org.uk/binaries/consultati...

Did the engineers check the joints in each of the boxes on the way to your home? I'd have expected that, at minimum.

In reply to a post by godsell4:

So after a little negotiation with BTO and PlusNet, I am not connected to FTTC.

On ADSL I used to get connected at about 3Mb line speed. 55dB attenuation.

On VDSL I am now connected at about 1.9Mb line speed, I will show you the stats from an unlocked HG612 in a moment. Sometimes it will connect at 3.5Mb but it will not stay connected for long. Frequently the modem may sync at just 0.5 to 1.2Mb, the SNR per tone graph on dslstats shows there is periodic noise on the line.

There are 2 new BDUK funded cabinets in the village.

It is about 2km on the E-side of the cabinet and about 1.6km to my home via the road, and the phone lines mostly follow that road, if anything they take a shorter route cutting off one of the corners en-route. The JDSU used by the BTO guy also showed it was 1.6km.

So the stats from the HG612 are currently.

xdslcmd info --pbParams
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 2
Max: Upstream rate = 1061 Kbps, Downstream rate = 3164 Kbps
Path: 0, Upstream rate = 1065 Kbps, Downstream rate = 2276 Kbps

Discovery Phase (Initial) Band Plan
US: (0,95) (868,1207) (1972,2783)
DS: (32,859) (1216,1963) (2792,3959)
Medley Phase (Final) Band Plan
US: (0,95)
DS: (32,859) (1216,1963) (2792,3959)
VDSL Port Details Upstream Downstream
Attainable Net Data Rate: 1061 kbps 3164 kbps
Actual Aggregate Tx Power: 10.5 dBm 4.6 dBm
============================================================================
VDSL Band Status U0 U1 U2 U3 D1 D2 D3
Line Attenuation(dB): 16.7 N/A N/A N/A 32.4 66.4 0.1
Signal Attenuation(dB): 16.7 N/A N/A N/A 32.4 66.4 0.1
SNR Margin(dB): 6.5 N/A N/A N/A 8.9 0.0 0.0
TX Power(dBm): 10.5 N/A N/A N/A 4.6 -128.0 -128.0
#

Another person, the other side of the village (they are not an immediate neighbour) has an attenuation of 36dB and is getting about 5Mb line speed. So my D1 attenuation of 32dB is in the same kind of ball park to theirs, they claim their line is stable at 5Mb.

So thoughts on these stats please?

The estimated download speeds for me even on an impacted line were 5.1 to 2 Mb.

And how to progress with BTO to make improvements? There are few or more likely zero spare pairs in the D-side cable.

I'm afraid you're flat out of luck.

We have to remember that we have an extremely old and dated aluminium/copper network. Lots of it was installed in the 1960's and has been there ever since.

FTTC is great when your cabinet is close - though it's completely pointless for lines such as yours.

Unfortunately your only options are to move house, or to pay megabucks for a leased line. I'd pick the former, unless you're prepared to live in the internet dark ages of 2-3mbit, where even content heavy websites take a few seconds to load.

IMO, life is too short to live with a 3rd world country service like that. I'd find a similar property in an area with either FTTP, Virgin Media, or one that's very close to a FTTC cabinet.

Good luck with whichever method you choose.

Edited by dave2150 (Fri 05-Jun-15 14:47:28)

I will read the pdf file later or over the weekend, but inside each grey box, to be able to pull out one or two pairs must mean the twisting in the cable has been disturbed which would give a poorer CMRR value every time. And at long distances that affect can not be good.

Did the engineers check the joints in each of the boxes on the way to your home? I'd have expected that, at minimum.

They have opened and checked and re-crimped the wires in the grey box nearest my house, but they have not opened up the others grey boxes back to the main DP.

In reply to a post by dave2150:

FTTC is great when your cabinet is close - though it's completely pointless for lines such as yours.

... the internet dark ages of 2-3mbit, where even content heavy websites take a few seconds to load.

It is not pointless, if it gets me an increase from 2Mb to 4-5Mb would be of great benefit, often ignored is the increase in upload speed. An increase to 1Mb or so on the upload side also allows things like VOIP and video conferencing to work much better for those who work from home, which is a lot of us in rural locations.

That reads like a fairly common rural scenario and is not abnormal.

So Yes, I have just had a good look at what I can find out about BT66 boxes and the grey boxes on the poles certainly look the same.

I know that much of the infrastructure was put in place a long time ago. Have BTO changed their practices to stop this happening on new installations? Or, has the idea of using the least possible amount of cable been the driving force the same as it was then as it is now?

I was told by the engineer that it looks like a 24-pair cable going past my house. The BT66 boxes have three holes, is that enough holes. I would have thought to supply 2 houses with a drop wire, and assuming all the joints are made inside the BT66, there would need to be 4 holes, 1 each for the 24-pair cable to loop-in and then loop-out, and 1 for each drop wire. And how is the cable kept neatly twisted as much as possible in that tiny space of the BT66?

I have not had a boost engineer out yet, after letting them do whatever they want first, I might suggest we try a single cable from the the DP connected only to the grey box on the pole outside my house so there is only one break in the cable from the DP to my house. Just as a test though it might be revealing in itself.

Edited by godsell4 (Fri 05-Jun-15 16:15:52)

Daft question perhaps.. but have you got any chance of 4G round where you are?

I was out in a remote-ish location the other day and despite not being in a built up area they had great 4G signal.

i.e. if you can't get an improvement to you're fixed line I am guessing you have had a look at other options.

I really feel for you though.. where I am moving too I'll still get a way faster connection than those in your situation... but its going to be a 1/5th of the speed I currently get and that bugs the heck out of me.

A BT66 can easily be modified in situ with further holes made in the bottom side.

(A quick diversion re. nomenclature. The "BT" is an abbreviation for Block Terminal, not British Telecom[munciations]. When the BT66 was first designed, there was a screw-terminal block insert which snapped into place within the enclosure. Subsequent developments showed that petroleum-jelly filled crimps were more reliable than screw terminals. So the terminal block insert was discontinued and the enclosure has become just an appropriate housing for gel-crimped connections.)

As for the mode of connection of the ultimate drop-cable to the premises, the multi-pair cable would have its outer sheath removed leaving all the pairs intact. The one pair to serve the premises would be identified within the bundle and then severed at the mid-point of all the exposed pairs. A pair of gel-crimps would then make the connection to the drop-cable that leads to the premises. The amount of de-twisting of any one twisted pair is minimal and would have an insignificant effect upon the overall performance of the circuit.

To the best of my knowledge, the minimum usage of materials to provide a telephony service still applies. Which nicely leads onto my next comment. We must keep in mind that the infrastructure was designed purely for telephony purposes. The fact that any broadband based service will also operate over it is close to amazing . . . just consider the power levels involved. The fact that the telephony infrastructure is used as a distribution medium is the reason why the standard broadband Internet access service is a "best effort" product, without any guarantee.

I did not mention in the original post the fact BTO disconnected me last Wednesday from FTTC and left me with no broadband at all not even ADSL.

I think somebody at BTO hit a button to remotely turn off FTTC at the cabinet. Is that possible?

Both my ISP and BTO say I have ADSL at the moment, which I do not. So can the wiring at the cabinets be left in a state where ADSL will not work? I am assuming it is the filtering on the E-side which is stopping the ADSL connection from the exchange getting to me.

BTO and my ISP say we have to treat this as a 'new order' to get this resolved. And this will not happen until this Friday.

In reply to a post by godsell4:

I did not mention in the original post the fact BTO disconnected me last Wednesday from FTTC and left me with no broadband at all not even ADSL.

I think somebody at BTO hit a button to remotely turn off FTTC at the cabinet. Is that possible?

Both my ISP and BTO say I have ADSL at the moment, which I do not. So can the wiring at the cabinets be left in a state where ADSL will not work? I am assuming it is the filtering on the E-side which is stopping the ADSL connection from the exchange getting to me.

BTO and my ISP say we have to treat this as a 'new order' to get this resolved. And this will not happen until this Friday.

TBO, I would say if you are really connected then for them to test the call back to the modem/router.
I know BT can and do tests between their end and our ADSL router/modem.

But yeah I would wait to the date they say.

Paul

In reply to a post by godsell4:

So can the wiring at the cabinets be left in a state where ADSL will not work? I am assuming it is the filtering on the E-side which is stopping the ADSL connection from the exchange getting to me.

Until the jumpers in the PCP (phone cabinet) that take your circuit to and from the FTTC cabinet are removed by an engineer, then yes. The ADSL signal is blocked on the FTTC DSLAM.