topic Re: Below Standard Wiring & Unusual Hot Weather Causes Major Problems in Plusnet Feedback

Below Standard Wiring & Unusual Hot Weather Causes Major Problems

Excalibre68 — Tue, 13 Sep 2016 15:45:32 GMT

Who should I happen to bump into today on my way to the post office but a BT Engineer working on my FTTC Cab.

I have had major problems with my fibre broadband over the last few months and after all of the tickets raised and OpenReach engineer visit my broadband is still in the toilet, the only replies I have had from PlusNet are "WE HAVE TESTED YOUR LINE AND FOUND NO PROBLEMS" & "YOU ARE WITHIN ESTIMATES"

I spoke to the BT guy working on the cab and asked him politely what he was up to, he replied just fixing a few issues because of some below standard wiring, I told him I had a few problems with my broadband and I am connected to the cab he was working on and could he check my connection to which he replied you will have to raise it as a fault before I can look into it. he then asked what kind of problems and I replied I've dropped from 65Mbs to around 45Mbs and it hasn't changed for months, like I've been capped or DLM isn't working.

He said yes probably heat as effected the DSLAM and DLM is holding you at 50Mbs band which is a know issue with ECI Cabs because of the compact size, very little space inside and poor ventilation.

Not much I can do about that he said, BT should never have implemented ECI cabs but they are cheap and save BT money and look better than the larger Huawei cabs.

Interesting stuff ?

Re: Below Standard Wiring & Unusual Hot Weather Causes Major Problems

rongtw — Tue, 13 Sep 2016 15:59:15 GMT

Not much I can do about that he said, BT should never have implemented ECI cabs but they are cheap and save BT money and look better than the larger Huawei cabs.

Insider information

Re: Below Standard Wiring & Unusual Hot Weather Causes Major Problems

kitz — Fri, 16 Sep 2016 09:25:33 GMT

Doubtful. Nothing he said rings true with known facts.

- The ECI M41's were supposedly more expensive than the Huawei MA5616T's
- Temp is constantly monitored.
- If anything the ECI cabs are too well ventilated. It's why Openreach had to install heat-pads in them for when the temperature drops to below 10°C

--------

PS.
Why has a mod moved this from the 'Fibre' section to 'Plusnet feedback'. Its nothing to do with Plusnet.

Re: Below Standard Wiring & Unusual Hot Weather Causes Major Problems

kitz — Fri, 16 Sep 2016 09:34:35 GMT

>>> DLM is holding you at 50Mbs

I'm not familiar with your line, so Im speaking without knowing the full facts and if it could be applicable to you.. but
1) We have seen many cases of DLM 'stuck capped speeds'. This is not cab related.
2) A sudden drop in speed is likely to be cross-talk. I lost 9Mb the other week when a new cross-talker came on line. All in all Ive 'lost' 32/33 Mbps of speed now due to cross-talk. Nothing Plusnet or Openreach can do about it.

Re: Below Standard Wiring & Unusual Hot Weather Causes Major Problems

Excalibre68 — Fri, 16 Sep 2016 13:22:18 GMT

Hey I'm just relaying what a Professional BT Engineer told me and would in all honesty believe what he has to say than conjecture on another forum.

I myself am an Electronics Engineer and have in the past designed and built PSU's "Power Supply Units" for Weir Electronics "TV PSU's"

I do know that thermal stresses can cause all major of problems and is the bane of the electronics industry.

A prime example is heat related issues in modular design "PC's use modular design and there are many know cases when people would have to reseat Ram Modules or Graphics Cards due to thermal stresses even in extremely well ventilated cases.

Prime components in electronics know to cause many issues are Electrolytic Capacitors these are temperature rated and the highest rating I have seen is 105 degrees centigrade.

Another case 'n point is caps have a tendency to dry out this changes the rated value and is not an actual failure.

All in all I would say the information he gave me is very viable and highly likely.

On the other matter of Crosstalk.

Check the link: https://en.wikipedia.org/wiki/Crosstalk

As the above info will show there are many different kinds of crosstalk but it all boils down to the same thing "Interference" and although it cannot be completely eradicated good filtering will normally deal with it.

Hope this clears things up for you.

All the best

Excalibre68

Re: Below Standard Wiring & Unusual Hot Weather Causes Major Problems

chenks76 — Fri, 16 Sep 2016 13:46:15 GMT

a "Professional BT Engineer"?

or might it have been an openreach engineer who was just wanting you to [-Censored-] off and leave him to get on with his work and say anything to get you to go away

or might it have been a MJ Quinn sub-contractor who just made up any old [-Censored-] to make him look clever in front of you.

Re: Below Standard Wiring & Unusual Hot Weather Causes Major Problems

Excalibre68 — Fri, 16 Sep 2016 14:51:03 GMT

What a witty reply, how long did it take you to think that one up

Stop trolling

Moderator's note by Mike (Mav): Full quote of preceding post removed as per Forum rules

Re: Below Standard Wiring & Unusual Hot Weather Causes Major Problems

MauriceC — Fri, 16 Sep 2016 14:12:20 GMT

@Excalibre68 There are quite a number of contributors on this forum with significant experience in both Electronics AND Telecommunications technologies so no lessons needed!

@kitz is a long standing and well respected contributor with a good track record in helping to resolve many problems over the past 10 years or so.

On the subject of trolls. Try holding up a mirror to find a close approximation of one.

Re: Below Standard Wiring & Unusual Hot Weather Causes Major Problems

Excalibre68 — Fri, 16 Sep 2016 14:35:19 GMT

Leaving derogatory comments doesn't help anyone.

You have your opinion and I have mine. "It' is a democracy"

Stop flaming my posts and get a life.

Re: Below Standard Wiring & Unusual Hot Weather Causes Major Problems

chenks76 — Fri, 16 Sep 2016 14:34:42 GMT

@Excalibre68 wrote:

What a witty reply, how long did it take you to think that one up
Stop trolling

there's certainly a troll amongst us, but i might suggest that you are looking in the wrong direction.
looking at your other posts and threads, i think it's clear which direction the troll is in.

Re: Below Standard Wiring & Unusual Hot Weather Causes Major Problems

Excalibre68 — Fri, 16 Sep 2016 14:45:16 GMT

Not sure what posts you are talking about but all the posts I've made have been information only.

Maybe you need glasses m8

And flaming my posts just shows your mentality.

Moderator's note by Dick (Strat): Full quote of preceding post removed as per Forum rules

Re: Below Standard Wiring & Unusual Hot Weather Causes Major Problems

kitz — Fri, 16 Sep 2016 19:14:03 GMT

>> Hey I'm just relaying what a Professional BT Engineer told me and would in all honesty believe what he has to say than conjecture on another forum.

That's fair enough. I just happened to point out that what he said didn't quite add up.
DLM will NOT be holding you back at the 50Mbps band just because you're on an ECI cab. If you want to believe it, then of course that is your choice.
Likewise, if you post something which doesn't make sense, then someone pointing this out doesn't make them a troll 😕

>> Check the link:

I'm very aware of what crosstalk is thank you.
It's specifically FEXT that causes most of degradation when it comes to xDSL lines.

However, I'm afraid you are wrong - it can NOT be dealt with by filtering.
It requires a very specific form of noise cancellation technique ie G.993.5 (G.vector)

>> Hope this clears things up for you.

Re: Below Standard Wiring & Unusual Hot Weather Causes Major Problems

Excalibre68 — Sun, 18 Sep 2016 17:41:12 GMT

However, I'm afraid you are wrong - it can NOT be dealt with by filtering.
It requires a very specific form of noise cancellation technique ie G.993.5 (G.vector)

>> Hope this clears things up for you.

Vectoring Technology

The technology uses noise cancellation, in a similar way to noise-cancelling headphones, to increase data speeds on existing copper infrastructure.

Vectoring technology measures and cancels interference across hundreds of lines over the full frequency spectrum they occupy

The interference is filtered by subdividing the spectrum into narrow frequency bands, known as tones, and filtering each tone independently.

Note The Words "Filtered & Filtering"

I know it's not as simple as filtering main hum on a PSU but I stand by what I posted.

You may also find interesting:- Nonlinear filtering algorithms for vector processing machines

http://www.sciencedirect.com/science/article/pii/0898122180900401

Re: Below Standard Wiring & Unusual Hot Weather Causes Major Problems

ejs — Sun, 18 Sep 2016 17:33:47 GMT

And, like the vast majority of lines, yours probably doesn't have vectoring. Modems that provide detailed stats can show if vectoring is in use or not.

Re: Below Standard Wiring & Unusual Hot Weather Causes Major Problems

Excalibre68 — Sun, 18 Sep 2016 18:05:09 GMT

ejs, you are absolutely correct my friend most broadband lines use interleaving.

Interleaving involves the use of powerful error-correction algorithms to improve broadband speed and stability on long or noisy phone lines. We use it as a matter of course on our broadband lines including BT Infinity lines where the connection between the street cabinet and your home is over copper cable.

While interleaving helps make your broadband faster and more stable, it can also increase the delay (latency) of your connection by up to 40ms (milliseconds). While most people wouldn't normally notice this, it can adversely affect some delay-sensitive applications such as certain online games.

DLM will NOT be holding you back at the 50Mbps band just because you're on an ECI cab.

I didn't say it was because I'm on an ECI cab just that my speed seems locked at around 50Mbs, and I read on your site somewhere it might be it's just stuck.

I have great admiration for Kitz and believe it's a great source of info and help.

All the best.

Re: Below Standard Wiring & Unusual Hot Weather Causes Major Problems

ejs — Sun, 18 Sep 2016 18:03:02 GMT

Interleaving and vectoring are independent features. Interleaving may be switched on or off irrespective to whether your cabinet is one of the few with vectoring in use.

PS. Feel free to link to something rather than copy and paste.

Re: Below Standard Wiring & Unusual Hot Weather Causes Major Problems

kitz — Sun, 18 Sep 2016 22:55:45 GMT

The term filtering, is taken to mean filtering out specific tones available for use to prevent interference on certain tones. - ie a broadband filter (low pass) strips out high frequency tones and ensures that only the lower tones used by POTs can pass through.
Another example is an RF3 which is sometimes fitted by Openreach to filter out problematic tones which are susceptible to RFI, they used to use these for EU's who lived near radio transmitters, but these days they have fallen out of favour as they often reduce sync speed on ADSL lines and seldom used with VDSL.

Im not quite sure where you got that quotation from, but someone seems to have amended what was 'processing' to 'filtering'. The original source from Alcatel-Lucent says:-

The technology uses noise cancellation, in a similar way to noise-cancelling headphones, to increase data speeds on existing copper infrastructure.

../snip/..

The interference is processed by subdividing the spectrum into narrow frequency bands, known as tones, and processing each tone independently.

Although the original link is now dead, numerous sites re-quote the Alcatel article using the correct term 'processing'. eg here and it can still be viewed on Wayback machine.

With DSL's G.vectoring, the tones are processed in real time to develop anti phase compensation signals. These anti-phase signals cancel out the noise to give a cleaner broadband signal.

I'm trying to think of a very simple analogy to explain G.vectoring and why the term filtering is incorrect, the best I can come up with off the top of my head is:-

Say you have a wall that is painted a nice shade of mid-grey (clean signal). But then someone splashes black paint over it (noise), by careful analysis of the shades and tone of black we take its exact opposite colour white (anti-phase) in order to balance (vector) back to grey.

Filtering is the equivalent of removing a brick from the wall so that you can't see the black paint (noise).

>> You may also find interesting:- Nonlinear filtering algorithms for vector processing machines

Thank you for the link, but closer inspection it appears to be specific to vector processors and not DSL related. The term 'vector' is quite generalised and can be used to describe several different things. For eg Photoshop uses vector graphics and filters, but these aren't the same as the G.vector transmission method that can be used with VDSL.

Re: Below Standard Wiring & Unusual Hot Weather Causes Major Problems

kitz — Sun, 18 Sep 2016 22:57:35 GMT

It's an ECI cab.. hence me saying nothing that Plusnet or Openreach can do.

Well.... unless Openreach decide to rip out all the M41's. I'm sure a quite a lot of people would like that.

Re: Below Standard Wiring & Unusual Hot Weather Causes Major Problems

kitz — Sun, 18 Sep 2016 23:09:17 GMT

>> my speed seems locked at around 50Mbs, and I read on your site somewhere it might be it's just stuck.

Yes it is possible that you may have a 'stuck' capped rate and it is one of the alternatives I mentioned because there seem to be quite a few around atm which just wont seem to clear. We'd need to see proper line stats to be sure - its usually quite easy to spot. Doing something about it though is a lot harder. 😕

However, barring a line fault, cross-talk is the usual reason for a large sudden drop in speed - as I mentioned I've lost circa 33Mb headline so far.

Last year I did a very rough analysis using stats from those who monitor their lines on my forum and who were on the cab since new. It averaged out at about 20Mbps per line. Its also not over yet. I thought mine was stable at ~24Mbp loss... until this month I got yet another cross-talker and another 9Mb instantly disappeared.

Honestly no amount of filtering will make any difference, It would take Openreach to roll out vectoring nationwide. The chances of that happening, look slim to nothing right now.

I don't disagree with your original post that with hind sight the M41's were a poor choice for Openreach to make because of their inability to do system level vectoring... (and the G.INP issues)... its just the rest of it didn't seem to quite make sense.

Re: Below Standard Wiring & Unusual Hot Weather Causes Major Problems

ejs — Mon, 19 Sep 2016 18:19:00 GMT

Excalibre68 wrote:

On the other matter of Crosstalk.

Check the link: https://en.wikipedia.org/wiki/Crosstalk

As the above info will show there are many different kinds of crosstalk but it all boils down to the same thing "Interference" and although it cannot be completely eradicated good filtering will normally deal with it.

My point was, that if Excalibre68 thought crosstalk wasn't a problem due to "filtering" as they called it, or vectoring as anyone else would have called it, they're going to be disappointed when they find out there isn't any vectoring on their cabinet.