Sync Speeds Slowly Dropping - Advice required

I have been with BT Infinity for approximately one year and over that time my sync speeds have gradually dropped from 80/20 to 57/17 and I'm wondering whether there is a problem on my line or do I accept the fact that it's caused by crosstalk?

My initial stats when i was syncing at 80/20 can be found here:

http://i491.photobucket.com/albums/rr278/icemansin/J...

Here are the stats for my current sync speed of 57/17:

http://s491.photobucket.com/user/icemansin/media/JDS...

Can anyone spot an obvious problem? Or is this just down to crosstalk?

I have called BT customer services who have finally agreed to send a BT Openreach Engineer out (after spending several hours on the phone to them) as my speeds have now dropped below the initial estimated speeds I was quoted of approx 63/20. Do you think I should proceed and go ahead with the appointment with the BT Openreach Engineer or is this a waste of time?

Any input/advice would be appreciated.

From just skimming over it looks very much like Crosstalk. I say don't cancel the engineer though I doubt he will find anything, it's always nice to have your line checked now and then.

The Hlog graph hasn't changed, suggesting no real difference to the physical line.

The QLN graph shows the increase in noise throughout the spectrum, suggesting crosstalk. The SNR graph corresponds to the increase in noise by showing less margin available for signal - again, throughout the spectrum.

The sync data indicates that you are still on fastpath, without FEC or interleaving downstream (R=0, D=1 respectively). A higher error rate, but obviously not enough to trigger DLM.

What's the new estimate?

In reply to a post by ryant704:

From just skimming over it looks very much like Crosstalk. I say don't cancel the engineer though I doubt he will find anything, it's always nice to have your line checked now and then.

But should I worry about the fact that if they don't find a fault, that I could potentially be charged for the call out?

In reply to a post by WWWombat:

The Hlog graph hasn't changed, suggesting no real difference to the physical line.

The QLN graph shows the increase in noise throughout the spectrum, suggesting crosstalk. The SNR graph corresponds to the increase in noise by showing less margin available for signal - again, throughout the spectrum.

The sync data indicates that you are still on fastpath, without FEC or interleaving downstream (R=0, D=1 respectively). A higher error rate, but obviously not enough to trigger DLM.

What's the new estimate?

Thanks WWWombat.

The new speed estimates from BT are the following: 53.5Mb/13.2Mb.

From what you're saying it seems like the reduction is down to there just being more noise being caused by crosstalk? I never thought it would wipe over 20Mbps from my sync speed though.

Do you think a BT Openreach engineer would be able to do anything? Maybe change to a different port in the FTTC cabinet? Or am I just clutching at straws? I have scheduled the appointment for this coming Friday, so I still have time to cancel, if need be. My worry is that this will continue to drop and that I need to draw the line somewhere. I think that losing over 20Mbps from my sync speed is a massive amount and that it will only continue head south.

Edited by deleted (Tue 09-Jul-13 00:18:31)

You will only be charged if the problem is within your home, which is very unlikely as your speed reduction is due to crosstalk.

You can lose more than 20Mbps, I've seen a 32Mbps loss from crosstalk. Changing port won't really do anything it might make the Discovery and Medley phase better or worse, it isn't worth bothering about.

You need to hope that Openreach actually adopt and roll out Vectoring, it's currently being trialed. I would imagine it will be rolled out or they're going to have some problems in the future and a bunch of angry customers (so to speak).

In reply to a post by ryant704:

You will only be charged if the problem is within your home, which is very unlikely as your speed reduction is due to crosstalk.

You can lose more than 20Mbps, I've seen a 32Mbps loss from crosstalk. Changing port won't really do anything it might make the Discovery and Medley phase better or worse, it isn't worth bothering about.

You need to hope that Openreach actually adopt and roll out Vectoring, it's currently being trialed. I would imagine it will be rolled out or they're going to have some problems in the future and a bunch of angry customers (so to speak).

Thanks ryant704.

Do you think that unlocking the BT openreach modem would cause an issue? Or do you think I should reset everything back, for when the engineer arrives?

So if this drop in sync speed is solely down to crosstalk, it looks like I'm a bit screwed. However BT customer services have stated that they are obliged to provide speeds that I was initially quoted in the estimate before signing the contract (which is 63Mb/20Mb). So how are they going to resolve this then? Or are they not in breach of the contract?

Edited by deleted (Tue 09-Jul-13 00:19:57)

Nah, the Modem is phone he may question it if it's a HG612 and your vendor is an ECI but just say it's there so you can monitor the line.

That is correct, they will allow you to change ISP without you needing to pay the remaining time of your contract or they will offer to knock a bit of your bill.

There is no way to get your speed back, changing ISP won't fix the problem but could be a reason to leave to join a better deal for the summer.

So the BT Openreach engineer came round today and did a few checks and as expected, no problem was found on the line. He did mention that the underground cabling in the area wasn't the best as there is a mixture of both Aluminium and Copper.

He then rang and reported the results to someone and was told not to investigate further as I'm within the estimates provided. The only thing is that they were basing this off the new estimates provided not the ones that were given when I first signed up to BT Infinity.

I guess I'm just stuck now right?

I believe you have two options now which are...

1. Complain to your ISP that you didn't sign the contract for the current estimates, they will either push for further investigation or allow you to be released from your contract without paying the remaining amount of months. If BT they will deny both but Ombudsman should allow you to leave.

2. You bite the bullet and live with it.

It's probably true you cannot get anymore speed but it's always nice to see what offers and services some ISP are currently offering.

Edited by deleted (Fri 12-Jul-13 15:59:28)

In reply to a post by ryant704:

1. Complain to your ISP that you didn't sign the contract for the current estimates,

That is an oxymoron unless the estimates are warranted to be accurate within a given tolerance; and they are not AFAIK.

Edited by deleted (Sat 13-Jul-13 14:54:57)

If that was the case, ISPs wouldn't use the 25% rule with them.

Ofcom requires ISP's to give accurate estimates of their broadband upon sale.

Edited by deleted (Sat 13-Jul-13 15:27:04)

I had a similiar drop in sync 4 months into my contract which is slightly still above my original estimate of up to 55mb. Seemed to happen just after my neighbor had their fttc service installed.

Bound to be in relation to crosstalk just hope there is no further drops.

roll on vectoring.

Edited by deleted (Sat 13-Jul-13 16:36:03)

In reply to a post by Icemansin:

The only thing is that they were basing this off the new estimates provided not the ones that were given when I first signed up to BT Infinity.

I guess I'm just stuck now right?

I recall seeing some slides from one of BT's meetings with ISPs, dating back to 2010 or 2011, for the "fibre trial working group". The issue of estimates came up, with an answer that implied that BT would be getting the estimates more accurate (which looked like *raising* them), and stated an aim of making sure that the estimates allowed for 1-2 years of crosstalk growth.

I say that only to point out that the field of crosstalk, growth, and estimates is a fluid one. In reality (because no-one is immune from the laws of physics), we unfortunately need to accept that there is nothing to be done (yet) about crosstalk. And that means we need to be realistic about those estimates too - a sudden spurt of take-up can have a nastier-than-expected impact.

If there were a fault, then that is a different matter. But it appears there isn't one - or at least not a detectable one.

So, yes, IMO, you are stuck. At least until vectoring comes along.

If you wanted to push it further, you could try. But to what end? To ditch the contract, or to get a faster speed? The latter seems unlikely.

In reply to a post by Icemansin:

So the BT Openreach engineer came round today and did a few checks and as expected, no problem was found on the line. He did mention that the underground cabling in the area wasn't the best as there is a mixture of both Aluminium and Copper.

He then rang and reported the results to someone and was told not to investigate further as I'm within the estimates provided. The only thing is that they were basing this off the new estimates provided not the ones that were given when I first signed up to BT Infinity.

I guess I'm just stuck now right?

Send a report to the ASA, it will do nothing for you now but they wont be pleased that BT dont use the estimates at point of sale.

thats ok for new customers but changing the estimate for a line post sale and then using the new estimate to determine acceptable performance is a breach of contract.

But even if it is a breach of contract, the appropriate course of action for the sufferer is what?

A very big IF it is a breach of contract.

Speeds dropping because of cross talk is one thing, speeds dropping because an ISP throttles everyone to 27.232Mbps would be another very different case.

If people need and want guaranteed speeds, then different technology and pricing will be needed. Unless the guaranteed speeds are very low.

It will be just crosstalk.

Crosstalk is not gradual. So you can join in, an extra 100 users can join up around you and create no crosstalk.
Then the 101th customer signs up, this customer alone can cause a huge amount of crosstalk and a huge drop in sync. Crosstalks so random and all it takes is that one customer to cause it.

Most people believe crosstalk builds up. E.g. 1 customer added, bit more crosstalk, 10 added, little more, 20 added a little more. That's wrong. It's immediate and usually caused by one source. Once you get it there's little you can do.

The estimate of 60 is pretty spot on with your 57. The estimates take into account crosstalk. 57 is still a very good speed and if using wireless 2.4ghz I doubt you'll see a real world difference as 57 is still pushing the limits of the WiFi.

I don't think this is a breech of contract. There's not a guaranteed speed by the ISP, it's a best effort. The estimate is fairly correct. You have to pay far far more for guaranteed speeds.

Edited by ukhardy07 (Sun 14-Jul-13 16:46:43)

In reply to a post by Chrysalis:

thats ok for new customers but changing the estimate for a line post sale and then using the new estimate to determine acceptable performance is a breach of contract.

Is it really a breach of contract?

I don't see anything in the terms & conditions (I'm looking specifically at BT's Infinity product) that there is *any* level of acceptable performance specified, whether relative to the estimate or not. In fact, there isn't even a statement that relates actual performance to the estimated performance.

I'm surprised, I must say. I thought I'd find something more than I did, but the text only states:

In reference to www.productsandservices.bt.com/consumerOrders/control/termsandcondi...:

The service we agree to give you includes [...] a high-speed fibre broadband service. Your speed will be estimated at the time of placing the order and will be the fastest speed your line can support.

It is hard to argue against this bit: "Your speed [...] will be the fastest speed your line can support."

Looking at the graphs etc it just looks like crosstalk.
Crosstalk can take huge amounts. People on slower lines often see 30Mbps turn into 15Mbps due to crosstalk.

Crosstalk on my line took 25Mbps. This is why your estimate was around 60Mbps - as that was accounting for the crosstalk. So they expected around 20Mbps of crosstalk at sign up. Clearly this was an overtime thing - so you wouldn't have experienced it immediately. The crosstalk is slightly worse than anticipated which probably just means takeup is higher than expected and you potentially have multiple sources of crosstalk, more than was expected.

Not a lot can be done as far as I'm concerned. SNR is pretty spot on. If interleaving kicks in you'd lose even more which is a possibility.

Edited by ukhardy07 (Sun 14-Jul-13 16:52:07)

Talking about just how much speed that crosstalk can steal from your line...

The Broadband Forum (a supplier group that helps standardise how broadband equipment should work) has a document on vectoring.

Figure 6, on page 12, depicts the effects of crosstalk at various distances (as well as the improvement made by vectoring).

For this discussion, note the difference between the two blue triangles (one upside down) at any one distance. The upper one shows the speed available if it was the only line in the system, while the lower triangle shows the 99% worst case possibility.

At 300 metres, the theoretical best/ideal case is a speed of over 150Mbps, while the worst case is only 50Mbps - so crosstalk causes two-thirds of the speed to be lost.

The blue crosses at each distance show the range of speeds actually seen by a variety of crosstalk-affected lines. At 300 metres, the best line ends up at 95Mbps, while the worst is around 65Mbps. (Note: They probably represent a higher take-up than we have seen in most of the UK so far.)

From what I've seen, BT's estimates, at any particular distance, fall somewhere between the lowest blue cross and the lowest blue triangle.

In reply to a post by RobertoS:

But even if it is a breach of contract, the appropriate course of action for the sufferer is what?

like i said is no immediate resolution.

best case scenario is they get a get out of jail free on their contract.

for ofcom/asa its a numbers game, if this becomes a widespread issue and enough complain, eventually the regulatory hand will be raised.

In reply to a post by WWWombat:

In reply to a post by Chrysalis:

thats ok for new customers but changing the estimate for a line post sale and then using the new estimate to determine acceptable performance is a breach of contract.

Is it really a breach of contract?

I don't see anything in the terms & conditions (I'm looking specifically at BT's Infinity product) that there is *any* level of acceptable performance specified, whether relative to the estimate or not. In fact, there isn't even a statement that relates actual performance to the estimated performance.

I'm surprised, I must say. I thought I'd find something more than I did, but the text only states:

In reference to www.productsandservices.bt.com/consumerOrders/control/termsandcondi...:

The service we agree to give you includes [...] a high-speed fibre broadband service. Your speed will be estimated at the time of placing the order and will be the fastest speed your line can support.

It is hard to argue against this bit: "Your speed [...] will be the fastest speed your line can support."

if ordering over the phone where the speed is quoted it probably is.

on my BT account page my estimated speeds are quoted as actual speeds of product.

One reason why BT and co are allowed to advertise full 80/20 speeds is they are supposed to give out reasonable estimates on order, they become unreasonable when they change post sale. If the speed is already below the estimate on activation and the customer was offered a cancellation, then it might be ok. If the customer initially hit estimated speeds and then the estimated speeds on file get changed post sale and if a fault occurs (loss of speed whatever cause is a fault to end user, they dont care if its crosstalk, or it may be a real fault such as damaged joints) then it can prevent an investigation even occuring as they simply get told they within estimates. I am pretty sure if this happened to me I could could force BT to drop my contract and maybe even refund me. I managed to get them to refund me over DLM as well as cancel my contract obligation.

The hand will raise, and the answer, ensure the sales estimate is well under what a line might be capable of

the hand may also force BT to readjust estimates higher for existing customers to match point of sale.

Note also openreach faults is currently under review by ofcom. I have already sent the report of to them brought up in this thread.

Edited by Chrysalis (Mon 15-Jul-13 19:37:33)

I understand from a technical standpoint why this is occurring. However from a consumer standpoint this is unfair. One should not expect their speeds to drop and pings to rise after the fact by such large margins. I really hope there is some hands raised over this issue forcing BT (wholesale or openreach whatever they are all the same company to me even though on paper they are supposedly not) to change their methodology and for ISP's to be a bit more forthcoming with their info before you signup (Only found out about DLM after I connected).

I really hope vectoring is the so called 'magic bullet' for the crosstalk issue that everyone seems to think it is. Hopefully it is rolled out soon.

In reply to a post by Oddball:

I understand from a technical standpoint why this is occurring. However from a consumer standpoint this is unfair. One should not expect their speeds to drop and pings to rise after the fact by such large margins. I really hope there is some hands raised over this issue forcing BT (wholesale or openreach whatever they are all the same company to me even though on paper they are supposedly not) to change their methodology and for ISP's to be a bit more forthcoming with their info before you signup (Only found out about DLM after I connected).

I really hope vectoring is the so called 'magic bullet' for the crosstalk issue that everyone seems to think it is. Hopefully it is rolled out soon.

Vectoring I feel will be like SRA.

Amazing when it works, but fragile needing right vendor equipment to work right.

The concern I have is that the goalposts have changed (with regards to the estimated speeds) from when I initially signed up with BT Infinity. It does seem easy for BT to get out of this by just saying that there is no fault as I'm within range of their new estimates.

The sync speed is continuing to drop (slowly) over the course of my contract, since I've been with BT Infinity (approx 1 year), but where do you draw the line? Will it continue to drop? When does it actually become an issue?

I know I'm probably stuck, and it's probably not worthwhile pursuing this further, but it is frustrating and even more annoying especially as I was syncing at much higher speeds not too long ago.

In reply to a post by Chrysalis:

Vectoring I feel will be like SRA.

Amazing when it works, but fragile needing right vendor equipment to work right.

I had a look at the latest version of SIN 498 earlier today. I think I told you a while ago that non-Openreach modems have to be vectoring-capable, but I now see something I don't think was there at that time. They are now required to support SRA.

In reply to a post by RobertoS:

In reply to a post by Chrysalis:

Vectoring I feel will be like SRA.

Amazing when it works, but fragile needing right vendor equipment to work right.

I had a look at the latest version of SIN 498 earlier today. I think I told you a while ago that non-Openreach modems have to be vectoring-capable, but I now see something I don't think was there at that time. They are now required to support SRA.

I already know they have to be vectoring capable, but that doesnt mean it will be enough.

The SRA requirement was there before as well.