Query about BT Wholesale FTTC Checker

Afternoon,

I'm looking to get upgrade my DSL connection to FTTC with Sky. I've done some checking on the BT Wholesale FTTC checker for my property and was wondering how accurate the results are.

My property is on a new build estate, built around two years ago and comprises of 67 properties. We are all linked back to the same PCP (Cab 4 @ Billingshurst, W. Sx). The cab is aprox 350mtrs from my property.

For my property and my immediate neighbours on one side, the BT checker gives the following:

FTTC Range A - 49.9Mbps Down / 11.8Mbps Up.

When I check using a neighbour's address on the other side of me (30mtrs away), I get:

FTTC Range A - 80.0Mbps Down / 20Mbps Up.


Why the discrepancy of nearly 30Mbps? I was looking at the 80/20 product but based on this, I think I may just go for the 40/10.

On my DSL with Sky I am currently getting:-

16Mbps down / 1Mbps up
23.0dB Attenuatation Down
6.0dB SNR Down

The line is rock solid, PPP session up for 16wks with no errors.

Here is a link to a screenshot from Google Maps showing the following:

C = BT FTTC Cab
X = Myself and neighbours where BT report FTTC speed of 49.9Mbps
N = Neighbour 30mtrs who could get 80Mbps

http://athena.tokenbay.co.uk/FTTC.jpg

The checker is an estimate based on factors that only BT seem to know. In your case and based on your current line I would suspect the checker has got it wrong. Have any neighbours already got FTTC that you could check actual performance?

The differences do sound a lot - it could be an error on one or the other or they could be correct. Do you know the EXACT route the cable takes from the cabinet and does it go near the 80Mb neighbour first and then how does it get to you? A quick check on the address checker does show a few oddities. Maybe you could plot speed against house on a map to see if there is any logic to it. I used http://www.dslchecker.bt.com/adsl/ADSLChecker.Addres...

If you are really 350m away then speeds in excess of 70 would be a reasonable expectation so I can understand why you are asking.

Why not ask Sky if you can choose a 40/20 product and then once you can see you line stats and performance, will they allow an upgrade to 80/20 with no penalties except maybe short extension to the contract period.


edit to add:

You could also be on different cables from the cabinet - there could be maybe three or four run to the estate or maybe some houses are on a cable used to provide service to another part before coming through to you whereas the 80Mbps estimates could be a new direct cable.

Edited by MHC (Thu 07-May-15 13:29:57)

One thing to watch with Sky is that the 40/10 product has an 18 month minimum term, but the 80/20 (Pro) product has a 12 month minimum term. If you start out with a 40/10, and then switch to 80/20 soon after (as I did), you will still be tied to the 18 month minimum term.It might therefore be better to start with 80/20 and get them agree to drop you down to 40/10 later, if you can.

The OP could be on a different DP which has only got paper estimates with no live feedback. That could explain the issue!

Would I be right in thinking you and the neighbour with the same estimate are both on Sky LLU or a TalkTalk LLU based telephone lines whereas the one with the high estimate is on a BT based telephone line?

If this is the case the difference is because the most accurate information is only from lines and addresses that have BT-based phone lines. The BT Wholesale checker has no real information on the others.

Post deleted by aquilla

MHC,

I've uploaded a Google Maps screenshot with all the house numbers pin pointed and also a spreadsheet containing all the FTTC (Clean) results from the BT Wholesale address checker for all 67 properties.

The blue line on the map is the route I think the BT cable takes from the High Street however I will try and check later.

http://athena.tokenbay.co.uk/Estate.jpg
http://athena.tokenbay.co.uk/FTTC.xlsx

@ip75. The 18 month contract doesn't worry me too much. I'm more interested in the upload speed rather that the download so if 40/10 suits my needs then that will be fine but I will speak to them to see what options are available.

Edited by aquilla (Fri 08-May-15 11:37:18)

@RobertOS. From looking at the SSIDs being broadcast in the immediate vicinity of properties 15 - 24, the majority of them are BT Hubs with a couple of Sky ones. I know one neighbour (who gets the same FTTC results as me) is definitely on BT as I've been in their property and seen the Hub (don't believe it was fibre).

Edited by aquilla (Fri 08-May-15 11:53:10)

I swithed to FTTC because the ISP claimed I would get between 32.5 and 36 megs, I get 19 megs. It (FTTC) is in my opion, over rated! Not worth the extra payment.

@tweak.
Have you double-checked with the ISP that everything is properly wired and set up correctly?
Have you run the bt wholesale test including Further Diagnostics to see what your profile is?
Have you tested with a wired connection to your router?

There are cases where an estimate over 30Mbps gives speeds under 20Mbps even when everything is correct (apart from the estimate), but they are pretty rare.

Update: So following a conversation with Sky regarding available options, I opted for the 40/10 service.

This went live at 5.30pm today (19th) and I am currently getting the following with their router:-

Text
1 23 4	Broadband Link     Downstream      Upstream Connection Speed   39998 kbps      5999 kbpsLine Attenuation   23.3 dB         0.0 dB Noise Margin       15.4 dB         6.6 dB

Speed test give me around 30Mbps down and 5Mbps up.

Going to leave it for a few days (as on the night shift at the moment) but am I likely to see the upstream increase from 6Mbps or will that be it?

In reply to a post by aquilla:

I've uploaded a Google Maps screenshot with all the house numbers pin pointed and also a spreadsheet containing all the FTTC (Clean) results from the BT Wholesale address checker for all 67 properties.

The blue line on the map is the route I think the BT cable takes from the High Street however I will try and check later.

http://athena.tokenbay.co.uk/Estate.jpg
http://athena.tokenbay.co.uk/FTTC.xlsx

Ah - blocks of flats, mixed in with houses.

A previous property I had was in a 1995-built estate, with a mixture of individual homes (many detached) alongside buildings with 9-10 flats in each.

In every case, the FTTC estimates for the flats were *considerably* better than the houses on either side. I never knew if the actual speed in any of the flats matched up to the estimates, but the one for my house was spot on.

The best explanation I had was that BT chose to deploy lines to the flats using thicker copper. Those would then experience lower attenuation, and higher speeds.

From the links, it doesn't looks like this has happened to you - quite the reverse, even.

One other point to remember is that BT creates the estimates by measuring the attenuation to the DP, and then making a standard allowance for the drop line between DP and the home. This means that every home connected to the same DP gets the same estimate ... which might be artificially high if the drop line is longer than allowed for.

That explains why the estimates come in batches.

For houses that distance from the cabinet, there is no real reason to have used thicker copper anywhere ... unless the lines are a long distance from the exchange - but your previous speed suggests this isn't the case.

Ultimately, it seem hard to fathom the difference in speeds - particularly the high-numbered houses running across the bottom of the map.

In reply to a post by aquilla:

Update: So following a conversation with Sky regarding available options, I opted for the 40/10 service.

This went live at 5.30pm today (19th) and I am currently getting the following with their router:-

Text
1 23 4	Broadband Link     Downstream      Upstream Connection Speed   39998 kbps      5999 kbpsLine Attenuation   23.3 dB         0.0 dB Noise Margin       15.4 dB         6.6 dB

Speed test give me around 30Mbps down and 5Mbps up.

Going to leave it for a few days (as on the night shift at the moment) but am I likely to see the upstream increase from 6Mbps or will that be it?

That's really not a good speed upstream, but the noise margin suggests there isn't much more to be squeezed out of it. It's a bit suspicious being a nice round 6Mbps - almost as though DLM has intervened ... which shouldn't happen in the first couple of days.

Having around 9dB spare on the downstream suggests to me that you can perhaps get another 25Mbps out of the downstream; by comparison, only getting 6Mbps out of the upstream is very paltry.

I would definitely be looking at your internal wiring with that upstream figure. Are you using a faceplate filter or the dangly filters from Sky? If the latter, are you plugged in on an extension? Can you try the test socket on the master socket?

At the moment it's connected to a dangly filter in the master socket as this was a self install. There is just one extension in another room. I'll try the test socket over the weekend however I have a feeling it won't improve (based on the 6dB SNR on the upstream figure).

I think the point is that perhaps the SNR is being suppressed by bad noise on the upstream.

When you try the test socket, also try to have one or two other filters to try out.

It'd do no harm to double-check that, when you have taken the faceplate off, none of the extension sockets can get dial tone.

In reply to a post by WWWombat:

I think the point is that perhaps the SNR is being suppressed by bad noise on the upstream.

When you try the test socket, also try to have one or two other filters to try out.

It'd do no harm to double-check that, when you have taken the faceplate off, none of the extension sockets can get dial tone.

Yeah I have a couple of spare filters and I'll try these when I get a chance over the weekend.

I think you may have to see if your router shows a 'max attainable' rate to see if there's any improvement doing what has been suggested.

There's plenty of extra snr on the downstream, so I reckon loosing the current bridge tap being caused by the extension may well pay dividends.

In reply to a post by ian72:

The checker is an estimate based on factors that only BT seem to know. In your case and based on your current line I would suspect the checker has got it wrong. Have any neighbours already got FTTC that you could check actual performance?

The checker is based on an Openreach system that I know the name of but can't put on here. It's basically a very accurate live map of the network, and it should know if there is copper or aluminium in the ground and what gauge the cable is. The speed estimate is to the DP only, so if the DP that serves you is out on a main road and you live on a farm half a mile away from it then the speed estimate will be too high.

Additionally over time it will change as there's an algorithm that also looks at existing FTTC lines on the DP and nearby DPs and assesses how they are performing.

In reply to a post by Zarjaz:

I think you may have to see if your router shows a 'max attainable' rate to see if there's any improvement doing what has been suggested.

There's plenty of extra snr on the downstream, so I reckon loosing the current bridge tap being caused by the extension may well pay dividends.

Hi Zarjaz,

The Sky Hub (SR102) only gives the current line rate. I do have a Cisco 887VA-W which I am planning on connecting up (once I reconfigure it for MER authentication) and that does have the option for "max attn rate" so we will see.

Will probably do this on Saturday and let you know.

In reply to a post by tweak:

I swithed to FTTC because the ISP claimed I would get between 32.5 and 36 megs, I get 19 megs. It (FTTC) is in my opion, over rated! Not worth the extra payment.

I do feel for you. A friend of mine was quoted anywhere between 15mb and 36mb. In reality he gets 10mb. Openreach have been out a few times, found and fixed line faults but has resulted in no increase in sync and his ISP have basically said tough luck (Sky).

Edited by deleted (Thu 21-May-15 20:11:59)

In reply to a post by digitalis:

In reply to a post by tweak:

I swithed to FTTC because the ISP claimed I would get between 32.5 and 36 megs, I get 19 megs. It (FTTC) is in my opion, over rated! Not worth the extra payment.

I do feel for you. A friend of mine was quoted anywhere between 15mb and 36mb. In reality he gets 10mb. Openreach have been out a few times, found and fixed line faults but has resulted in no increase in sync and his ISP have basically said tough luck (Sky).

Well while doing checks for some people I have seen ADSLx speeds being better that what they would get on FTTC all because the cabinet is closer to the exchange than it is to the homes and VDSL(2) isn't as forgiving over long distances as ADSLx is.

Paul

Afternoon,

I've just configured up my Cisco 887VA for use with Sky's MER authentication and plugged this into the test socket. Sync readings are:

Down: 39998Kbps
Up: 9995Kbps

The max attainable sync for the line according to the router is:

Down: 64160Kbps
Up: 15904Kbps


Just done a speed test and got 36Mbps down and 9.5Mbps up which isn't bad.

I'll give it a few hours and then look at reconnecting the extension socket and see what kind of difference this makes.

Following my earlier update, I put the master socket back together so the extension was live. When I reconnected the router the downstream remained around 39Mbps but the upstream dropped to about 7Mbps.

Also the max attainable rate dropped to around 49Mbps downstream and 7.5Mbps upstream.

So I think it's safe to say my internal wiring is causing the issue. Kind of disappointing as this is a new build property so I would have expected the cabling to be up to a certain standard!

I'll look into getting a VDSL faceplate off Amazon and fitting that.