topic Re: +/- 1 megabit? in Plusnet Feedback

+/- 1 megabit?

jimbof — Mon, 10 Jun 2013 12:25:57 GMT

There is a fairly common theme among a few posts on here - that is the reference to +/- 1 megabit. The whole point of the error bars is that that is the region within which your connection should be, unless it is further qualified (something like "95% of customer's will receive x +/- 1megabit") . I'm sure you could share the amount of customer's who are achieving their estimate or better expressed as a percentage?
I'm surprised Plusnet quote to this level of accuracy - less than a 2% margin for a full rate connection - and is the kind of numerical abuse you see all the time. It is even stranger when you consider this in the context that almost any DLM event is going to drop you by WAY more than 1megabit/sec.
Why not just change the wording on the +/- 1 megabit, as it is surely an unreasonably tight specification? It just seems to be setting yourselves up for failure really...!

Re: +/- 1 megabit?

Chris — Mon, 10 Jun 2013 12:54:44 GMT

We don't quote this anymore, it was a problem especially on the Fibre signups.
I've attached a screenshot of the new estimates for Fibre.

Re: +/- 1 megabit?

jimbof — Mon, 10 Jun 2013 13:20:59 GMT

i think it is still shown in the member's centre though - so that should probably be nuked too?
"Estimated line speed:
75Mb (Accurate to within +/- 1Mbit) - Checked on 2013-03-25 01:27:48"
Anyhow, good to see it isn't shown to new signups anymore.

Re: +/- 1 megabit?

jimbof — Mon, 10 Jun 2013 13:22:53 GMT

As an entertaining aside, BT Retail don't even quote the figure as an estimate! They do for ADSL but not for fibre. Go figure!

Re: +/- 1 megabit?

chrispurvey — Mon, 10 Jun 2013 13:38:38 GMT

This is going to change in the near future, we've made a few amendments to this, but it will require a new line check to be performed to update the details to remove the +- 1Mb/s which we're currently working out how best to do.

Re: +/- 1 megabit?

deathtrap — Tue, 11 Jun 2013 17:58:30 GMT

Problem is with any ISP using the BT Wholesale checker data for speed estimates is that is often inaccurate ,only recently BT have changed some of the speed estimates mostly to lower values, My line have always had an estimate that is inaccurate, more so with FTTC , fortunately for me my speeds are a lot higher , and if an isp,or BT openreach starts to rely upon BT 's speed estimates to to avoid acknowledging,diagnosing or reporting faults where something causes a big decrease in speeds it will be a sad day for the consumer

Re: +/- 1 megabit?

jimbof — Wed, 12 Jun 2013 06:28:28 GMT

I'm not sure I totally agree. FTTC for reasons of near and far end crosstalk will (for many customers) see a natural fall in performance as cabinets fill up and as more lines running in the same duct are activated for FTTC. So a line needs to be drawn in the sand somewhere - I think it is reasonable in many cases on FTTC that if the user was lucky enough to get a faster speed due to the cabinet being empty, and then dropping to the original speed estimate, that that can be considered to not be faulty.
I would imagine that to start with Openreach use a mathematical model, and then as the cabinet starts to fill up perhaps they fill in the model with actual results from lines (as there are always bound to be local factors such as aluminium, cable routes, etc). Or perhaps the overall model has changed now based on field data from more sites.
It would of course be nice to be able to see information about cabinet usage when the wholesale checker / speed tester runs, so that you can understand what has happened. You'd imagine that eventually most cabinets will be pretty much full, but it would help explain to people why the speed they are seeing might not last.
My original point (and I guess why plusnet have / are making the changes that they are) is that once you have an understanding of the technology you realise that there is no-way you could ever confidently provide estimates +/- 1megabit. Of course, the branding of FTTC as "fibre" products doesn't help, as you wouldn't expect a "fibre" service to degrade in this way. In fact, I'm a bit surprised that the ASA or similar haven't got involved over this branding as for quite a few people "fibre" can mean a kilometer of copper / aluminium if you are really unlucky. My ADSL service was "fibre" from the exchange!

Re: +/- 1 megabit?

deathtrap — Wed, 12 Jun 2013 13:45:18 GMT

They should be replacing all those under performing D'side pairs ideally with FTTP There is talk of vectoring ,but how well it will work (when rolled out) is anyone's guess really,
BT 's estimates are based on assumptions , and as every line is in some-way different .
those assumptions can be absolutely meaningless ,They are estimates and should never become more than that. or relied upon
I would bet that there are a lot of FTTC cabs in some areas that have very few connected to them, even 12mths after accepting orders

Re: +/- 1 megabit?

EnglishMohican — Sun, 16 Jun 2013 12:35:14 GMT

There is no fibre in our area so this is all for future information.
Are you saying that if in the future, I think I want to have fibre, then I am expected to sign up to a contract for 18months based on a cost that Plusnet guarantee to take precisely and regularly every month but for a service which they cannot define?
I can live with being given an estimate with an error margin on it but without the tolerance figure how bad does it have to get before Plusnet are no longer meeting their committment to deliver me a broadband service. At 70Mbps,I accept that a tolerance of +/-1 is pretty tight but at the bottom end of the possible range +/-1 is nothing remarkable without Plusnet now deciding it cannot even guarantee that.
And if I understand the previous posts correctly, having got fibre initially running at speed X, then it can legitimately and uncorrectably change to speed Y where Y could be X/2 or worse. And Plusnet are still going to go on taking the original amount of money for a service in this case only half as good?
Please tell me I have all of this wrong - surely I am not expected to buy an undefined service.

Re: +/- 1 megabit?

ejs — Sun, 16 Jun 2013 16:55:41 GMT

Plusnet and I think every other ordinary residential ISP are not going to guarantee you get any particular speed. Does 70Mbps falling to 50Mbps make much actual difference, besides for speedtest scores? It might matter more for the people whose FTTC speeds are closer to 30 or 20 Mbps, but then those people have to pay the same as those getting 77Mbps anyway.

Re: +/- 1 megabit?

EnglishMohican — Sun, 16 Jun 2013 18:33:03 GMT

Dredging my memory, I believe that Plusnet (or Openreach in reality I suppose) will not consider a fiber system adequately installed until it achieves at least 20Mbps. Can anybody confirm whether my memory is working and also whether that 20Mbps is a minimum initial speed that can subsequently drop to a lower speed without correction or is it a long term guaranteed minimum that will get all the troops leaping if it is breeched.
I accept that 50Mbps is not very different to 70Mbps in real life terms but an estimate either has some meaning or not. If it has meaning then it should have a tolerance or a confidence interval on it and the customer should be able to rely on that figure. If the figure is so meaningless that Plusnet/Openreach have no confidence in it then they should not be using it in their sales material. Doing so takes us into Quack Doctor territory and in my opinion, false advertising.
That tolerance would normally be a percentage of the estimate rather than an absolute figure. That is more true to real life and real engineering and obviously could be equivalent to 20Mbps at 70Mbps and 6Mbps (roughly) at 20Mbps though 14Mbps versus 20Mbps is certainly more disappointing than 50 versus 70.
If I buy a pint of milk, I do not mind a BOGOF offer that nets me two pints but I do object to finding I only get half a pint. Why should the internet be different? When I commit my money to Plusnet, what do Plusnet commit to me?

Re: +/- 1 megabit?

deathtrap — Mon, 17 Jun 2013 01:09:25 GMT

Quote from: EnglishMohican
There is no fibre in our area so this is all for future information.
Are you saying that if in the future, I think I want to have fibre, then I am expected to sign up to a contract for 18months based on a cost that Plusnet guarantee to take precisely and regularly every month but for a service which they cannot define?
I can live with being given an estimate with an error margin on it but without the tolerance figure how bad does it have to get before Plusnet are no longer meeting their committment to deliver me a broadband service. At 70Mbps,I accept that a tolerance of +/-1 is pretty tight but at the bottom end of the possible range +/-1 is nothing remarkable without Plusnet now deciding it cannot even guarantee that.
And if I understand the previous posts correctly, having got fibre initially running at speed X, then it can legitimately and uncorrectably change to speed Y where Y could be X/2 or worse. And Plusnet are still going to go on taking the original amount of money for a service in this case only half as good?
Please tell me I have all of this wrong - surely I am not expected to buy an undefined service.

That's basically how it is, as Xdsl is rate adaptive, they Openreach will not give any guarantees and they never have , infact the twisted pair copper local loop was never designed with broadband in mind,hence the lack of any kind of guarantee's the most you get out of them is their SIN specs , unless you get into the realms of leased lines or FTTP , My main gripe is the fact that the BT openreach/wholesale speed estimate for my line is and always has been inaccurate by a significant amount, lower , and that they base the first FTTC estimate on assumptions alone, as they are often given before the cab is accepting orders

Re: +/- 1 megabit?

Kelly — Mon, 17 Jun 2013 10:51:28 GMT

Quote from: EnglishMohican
If I buy a pint of milk, I do not mind a BOGOF offer that nets me two pints but I do object to finding I only get half a pint. Why should the internet be different? When I commit my money to Plusnet, what do Plusnet commit to me?

There is a significant difference between pouring the same amount of milk into a milk carton each time and ensuring that you are getting speeds to an estimate through multiple miles of connectivity equipment. You are comparing apples and oranges.
If you want to have an assured rate, you need a different product, perhaps a leased line of some sort. They are though, much more expensive. So, if you don't want to pay that much, you can settle for an product based on a technology which will run to an estimate but will be affected be a lot of different things.

Re: +/- 1 megabit?

EnglishMohican — Mon, 17 Jun 2013 21:25:51 GMT

Quote from: Kelly
You are comparing apples and oranges.

I would be paying with pounds for both.

Quote from: Kelly
There is a significant difference between pouring the same amount of milk into a milk carton each time and ensuring that you are getting speeds to an estimate through multiple miles of connectivity equipment.

Three thoughts - FIrst thought - perhaps if you had spent time designing the kit that fills thousands of cartons with a precise amount of milk an hour without splashing it all over the place you would not be so dissmissive.
Second thought. As I am sure you do know, electronics and communication technology is a science. If you know the properties of the wires and their lengths you can perform remarkably good calculations as to how they will perform. The problem seems to be that the Openreach database is full of errors - on my own line they offer an estimate on basic ADSL that is way in excess of anything that is ever going to be possible. An Openreach engineer explained that probably the database used to calculate the estimate contained the wrong data - that my line length was for my previous house or whatever. That is not professional, competent, statistical estimating - it is not even guesswork.
Third thought - you have not answered the question in my previous post - does Plusnet/Openreach guarantee any level of performance irrespective of the estimate. If so - is it 20Mbps?

Re: +/- 1 megabit?

ejs — Tue, 18 Jun 2013 05:58:32 GMT

How would a 20Mbps minimum guaranteed speed work in practice? What would happen if your FTTC estimate is "up to 21.8", but when the engineer installs it, they only achieve 19.5? After much fiddling around, replacing the master socket a couple of times, trying different ports in the FTTC cabinet, they can't manage to increase the speed to over 20. Would they then:

Undo the FTTC installation, restore the ADSL service, and say sorry you can't have FTTC, it turns out you're just too far from the cabinet, you'll have to stick with your 3Mbps ADSL?

Knock some amount off the price?

Install FTTPoD for free?

Return later to replace the entire copper cable between your house and the cabinet?

Re: +/- 1 megabit?

deathtrap — Tue, 18 Jun 2013 07:54:26 GMT

Quote
Undo the FTTC installation, restore the ADSL service, and say sorry you can't have FTTC, it turns out you're just too far from the cabinet, you'll have to stick with your 3Mbps ADSL?

would be the only viable option , as the other 3 choices ,not a chance

Re: +/- 1 megabit?

Kelly — Tue, 18 Jun 2013 09:06:20 GMT

Quote from: EnglishMohican
Quote from: Kelly
You are comparing apples and oranges.

I would be paying with pounds for both.

But you are paying for an estimated service.

Quote from: EnglishMohican
Quote from: Kelly
There is a significant difference between pouring the same amount of milk into a milk carton each time and ensuring that you are getting speeds to an estimate through multiple miles of connectivity equipment.

Three thoughts - FIrst thought - perhaps if you had spent time designing the kit that fills thousands of cartons with a precise amount of milk an hour without splashing it all over the place you would not be so dissmissive.

A factory designed to put milk into cartons is a significantly more controlled environment than a countrywide telecoms network with different distances, materials and technology. I'm not being dismissive, you're oversimplifying it a bit.

Quote from: EnglishMohican
Second thought. As I am sure you do know, electronics and communication technology is a science. If you know the properties of the wires and their lengths you can perform remarkably good calculations as to how they will perform. The problem seems to be that the Openreach database is full of errors - on my own line they offer an estimate on basic ADSL that is way in excess of anything that is ever going to be possible. An Openreach engineer explained that probably the database used to calculate the estimate contained the wrong data - that my line length was for my previous house or whatever. That is not professional, competent, statistical estimating - it is not even guesswork.

It would be possible to install an FTTC line into every house around the country, then run a speed test off it to populate that database. That would be the accuracy you wanted. However the costs of that would be extreme and you wouldn't want to pay for it.
Estimates are estimates. They are worked out from what Openreach know about the area, the exchange, the technology that's there, the distance of the building from the cabs. They can't test all those lines though. There have been estimates made where the building looks close to the cab but it turns out the wiring is significantly different and goes a non-expected route.
It gets even more complicated when you consider that things entirely out of Openreach's control could impact your speeds. I'm thinking REIN interference causing problems.
Happily, most people find their estimates seem pretty good, and we'll do what we can to try and improve speeds where those estimates aren't being met.

Quote from: EnglishMohican
Third thought - you have not answered the question in my previous post - does Plusnet/Openreach guarantee any level of performance irrespective of the estimate. If so - is it 20Mbps?

There is a the OFCOM code of practice on Speeds which includes some guidance around what happens if you can't achieve your estimates. Also, we'd be reasonable. I.e. if you aren't getting any better performance than you'd get on copper, we'd look at what we could do. There are no "guarantees" though.
http://stakeholders.ofcom.org.uk/telecoms/codes-of-practice/broadband-speeds-cop/voluntary-codes-of-practice/

Re: +/- 1 megabit?

EnglishMohican — Tue, 18 Jun 2013 10:25:54 GMT

Quote from: Kelly
But you are paying for an estimated service.

Without a confidence interval, an estimate is meaningless. That's a mathematical fact - not just me being difficult.

Quote from: Kelly
It would be possible to install an FTTC line into every house around the country, then run a speed test off it to populate that database. That would be the accuracy you wanted.

Now you are over simplifying Yes, of course that would be possible but then it would be a measurement that was being quoted, not an estimate. I am asking for an estimate with a confidence interval and some defined corrective action when the confidence interval is breeched.

Quote from: Kelly
There have been estimates made where the building looks close to the cab but it turns out the wiring is significantly different and goes a non-expected route.

Are you seriously telling me that BT base their estimates on how the crow flies distances rather than knowing the route/distance that their ducts take? In any case, I have ADSL so they know the performance of the line from the exchange to my house. If they install fibre to my cab, they surely take measurements to establish the difference between the exchange/cab copper and exchange/cab fibre lines. Some arithmetic could then give them a good estimate of what I would receive, an estimate good enough to base a commitment on.

Quote from: Kelly
.... we'll do what we can to try and improve speeds where those estimates aren't being met.
.... we'll do what we can to try and improve speeds where those estimates aren't being met.
Also, we'd be reasonable. ............ we'd look at what we could do.

But these are the sort of meaningless phrases that I have a problem with. None of these phrases actually commit you to more that 30 seconds thought and then you could decide you can do nothing. This is marketing speak.

Quote from: Kelly
There is a the OFCOM code of practice on Speeds which includes some guidance around what happens if you can't achieve your estimates.

I read it and was unimpressed. Its full of "significant shortfall" leaving "signicant" undefined, "transfer to a lower speed package" but "where one is offered". Its totally toothless.
I think you must all be tired of my views by now so I will not pursue this thread further except to say that you stand no chance of getting me to sign up to an 18 month contract where I am committed to paying you money for a service that you willnot/cannot define in a scientifically meaningful way. I am not buying marketing speak and wild optimism.

Re: +/- 1 megabit?

w23 — Tue, 18 Jun 2013 10:44:11 GMT

Interesting post on this blog relating to FTTC speeds: http://revk.www.me.uk/2013/05/the-rules-of-fttc.html

Re: +/- 1 megabit?

Townman — Tue, 18 Jun 2013 12:51:29 GMT

Quote from: Kelly
Estimates are estimates. They are worked out from what Openreach know about the area, the exchange, the technology that's there, the distance of the building from the cabs. They can't test all those lines though. There have been estimates made where the building looks close to the cab but it turns out the wiring is significantly different and goes a non-expected route.
It gets even more complicated when you consider that things entirely out of Openreach's control could impact your speeds. I'm thinking REIN interference causing problems.

Estimates are indeed estimates but they should be informed by known data. If BTOR do not know where their own cables / ducts run then they are even bigger idiots that I already take them for. The long and the short of all of this is BTOR are ducking and diving rather than investing their many £m profit into fixing ancient poor infrastructure - especially in rural areas. PN have done a great job in harassing BTOR to get my (business) circuit fixed, so that it delivers something more like what it should for the line characteristics. The journey has not been helped by E-Side circuits spec'd at 36dB attenuation only delivering 47dB attenuation. This suggests a fault which ought to be rectified - Oh NO that means opening up the air tight E-Side trunks and might mean replacing some cable... cannot do that as it will cost money.
As for the D-Side that suffers from West Coast Main Line Virgin Train REIN. The source of REIN might possibly be outside of BTOR's control, but protection from it should come from the provision of circuits / cable appropriate for the environment and / or BTOR should be seeking elimination of such sources of REIN under the interference to / with telecommunications legislation.
BTOR is little more than a stream of excuses for not fixing their monopoly supplier position.