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[gazaai]

Hi thanks for the information, I see what you mean now. What do you recommend my next course of action is?

How can I get an engineer out if my speed is way above the minimum given to me?

Thanks

[Black Sheep]

Hi thanks for the information, I see what you mean now. What do you recommend my next course of action is?

How can I get an engineer out if my speed is way above the minimum given to me?

Thanks

You have to request this via your ISP, who in turn will liaise with Openreach ...... who will run a 'GEA Diagnostic Test'. This test will indicate (amongst many other things) if there is a 'Bridged Tap' affecting the circuits performance.

If any anomaly is found, then your ISP would hopefully call you back to arrange a convenient time for an engineer to visit. I haven't read through all this thread, haven't got the time I'm afraid, so I'm assuming you've performed all the checks you possibly can ?? IE: Master socket etc ..... ??

If so, the 'Tap' could quite easily been in the Cabinet, if indeed identified. 

[gazaai]

That was my first post on this thread, the line comes in straight to my master socket with no joints and has no extensions. I have created a forum post on BT forums. As they seem to be pretty helpful at getting stuff done. Thanks

[WWWombat]

Back to @Cloudane shortly...

Ach - I had quite a post written out, then accidentally lost it.

A quick summary of what I worked out
- Hlog graph nice and smooth, and seems to match the attenuation
- QLN graph shows the line to be noisier than comparable lines, for tones above 512, by 5dB - 10dB
- This extra noise probably accounts for 15-20Mbps lower speed
- Because the noise applies fairly evenly across the spectrum, but only above tone 512, it looks like crosstalk from other FTTC subscribers
- So most of the speed drop, over time, appears to be from crosstalk.
- Overlaid over this will be DLM interventions, and de-interventions, causing speed reduction/increase of 5-6Mbps.
- The DLM intervention that applied until this morning was at the "standard" level of intervention. No sign of anything more than that, and no banding.
- The main thing to watch will be the ES rate over each 24 hour period. 600-800 ES's per day is OK for speed-profile ISP's like Plusnet (I used to see that consistently).

I'd say the only things that can be done will be focussed on keeping DLM uninterested in your line,by either
- Reducing the slow accumulation of ES's over the course of a day, or
- Stopping the occasional "large peak" in ES's that trip you over the DLM threshold

The former could be helped by any number of small changes - the DSL cable, a new filter/faceplate, checking wiring and joints, and not running close to power lines. Whenever you make a change, restrict it to one thing at a time, and then monitor the "Errored Second" graph for a few days, to see if it has made an impact. (Tick the "Totals/Averages for ES Graphs" box in the footer, to get some extra helpful lines on the graph).

The latter is best helped by trying to figure out what event causes the large peak, and eradicating that.

On the other hand, getting BT to deploy G.INP on ECI cabinets would probably stop any more DLM intervention in one fell swoop.

Then we had ONE bad minute or so of noise on the graph and it slapped it back on again and has stayed on ever since.

Are you sure?

One bad minute, with very high CRC counts, can still only add 60 errored seconds onto the ES counter. It shouldn't have too much of an impact, by itself.

[gazaai]

Unfortunately BT are saying they cannot send an engineer as my speed is above the minimum estimated speed :/
I'm not sure what else I can do...

[WWWombat]

@gazaai

BT (at the wholesale/openreach level) are quite reticent about investigating problems that are just speed problems, until you go below a (very low) threshold speed. The job of the ISP (including BT at the retail level) is to check your speeds against those thresholds, and then to politely decline investigation.

However, if line tests are run by the ISP, that independently confirm a line fault, then the fault should be passed down.

So, if the agent you talked to at BT has run a diagnostic test, and it couldn't find a problem, then there is indeed not a lot you can do. Except keep monitoring ...

However, if you were put off without any kind of diagnostic test being run, you probably need to go back to them with a slightly different approach.

I don't have much experience of what to say to BT Retail to get them to perform the tests. Perhaps someone else can advise...

[gazaai]

"You are just going to waste your money, there are many things that affect speed which are not shown on the estimates.
Aluminium cable is one of them.
 
The actual likelyhood of a teed in pair from the cabinet to your house, is very slim. I think you are being misled, and I am sure others here would agree.
 
In fact, just having a visit would interrupt the line a few times, and DLM would then reduce your speed, and it could take weeks to recover. Its best left alone."

There are now saying I am being misled. Even tho I can see by myself from the pdf you linked me that it does look like there is an issue with my line like a bridged tap. Ill need to see what else I can say to get an engineer out

[Black Sheep]

"You are just going to waste your money, there are many things that affect speed which are not shown on the estimates.
Aluminium cable is one of them.
 
The actual likelyhood of a teed in pair from the cabinet to your house, is very slim. I think you are being misled, and I am sure others here would agree.
 
In fact, just having a visit would interrupt the line a few times, and DLM would then reduce your speed, and it could take weeks to recover. Its best left alone."

There are now saying I am being misled. Even tho I can see by myself from the pdf you linked me that it does look like there is an issue with my line like a bridged tap. Ill need to see what else I can say to get an engineer out

Where are you getting that info from

Agreed, the chances of a 'Teed in pair' at the Cab are quite low, but on Quante and Krone Cabs, I've removed enough of them in my time to say there's a chance !! Ask our very own Bald Eagle about his own Broadband issues ...... one of them being a 'Tap' in the Cab.

If the fault is raised as an FTTC Repair, then we can intervene in the network as many times as we care to, or until that chap on the Moon in the John Lewis adverts gets back to Earth, it doesn't matter about the DLM, as we will (or should) re-calc (reset) the DLM.

Where you go from here is purely down to your tenacity and your ISP. But for tech advice ..... please, take it from this forum. 

[gazaai]

I created the forum post here: https://community.bt.com/t5/BT-Infinity-Speed-Connection/I-have-been-told-I-have-a-bridge-trap-on-my-line-so-how-can-I/td-p/1562540/highlight/false

Which turned into all the mods pretty much laughing at me for wanting to reach 80/20 and saying I should donate the money to charity or burn it in a fire instead of paying for an engineer. Thanks for the information guys, at the moment there is a congestion issue with my exchange giving slow speeds at peak times. So I can probably use that excuse to get an engineer out without question, as I did the last time but I cancelled it once I found about the known issue. This is the second time my exchange has had congestion problems. Then from there once he arrives maybe ask him to take a look at a possible Bridge Tap issue.

[Black Sheep]

Absolutely.

For clarity, I'm not personally saying you have got a Tap, but Wombat is pretty damned clued-up with these things. I'm just throwing my two'penneth in regarding what can and does happen in the network from Exchange to Home.

As I've pointed out previously though, Openreach's GEA Diagnostic tool, accessed via WHOOSH, performs a test that 99% of the time will identify remotely if there is a Tap on the circuit, along with excessive X-Talk, REIN and/or RFI.
Like any remote testing, things can slip through the net, but I have found this particular tool to be the best we have.

Good luck. 

[Cloudane]

Thanks very much for the detailed analysis @WWWombat

Ironic that it finally retrained this morning after something like 72 days of interleaving, after I posted.  The DSLAMs have ears!

So it sounds like the biggest drop is down to crosstalk.  If that's the case I can live with that - I'm not exactly happy about it, but it means it's outside of anyone's control so there's no point in being concerned about it.  I'm a little surprised as it's a very small and quiet estate and I'd not have thought there'd be many people actually connected to FTTC here (maybe I'm not giving the locals enough credit, but I wouldn't have thought many of them would be 'technical' enough to understand why they'd even want it) but maybe it just takes one other user to kill it.

What baffles me a little bit is that a wired connection is slower than the mobile network these days which manages a solid 60mbps from a mast about a mile away.  If only mobile data wasn't so expensive, there'd be room for it to replace BT's wired telephone system at this rate!

Will look more seriously into trying that replacement cable etc to at least calm DLM down.

As a matter of interest, though it's connected at 46 now, speedtest.net is still returning the same throughput of 36 as before.

On the other hand, getting BT to deploy G.INP on ECI cabinets would probably stop any more DLM intervention in one fell swoop.

From what I was reading on one of the other threads, ECI cabinets are very unlikely to get G.INP (and were never going to get vectoring - something about the boards not having space for the necessary module).  Might be an idea to switch to a 40/10 package and save money if it's going to run at 40 most of the time anyway.

Are you sure?

One bad minute, with very high CRC counts, can still only add 60 errored seconds onto the ES counter. It shouldn't have too much of an impact, by itself.

Ah maybe that was an exaggeration.  It didn't look like much, it was a single spike in the errors graph that didn't last long at all, but maybe it was longer than literally one minute.

[NewtronStar]

As a matter of interest, though it's connected at 46 now, speedtest.net is still returning the same throughput of 36 as before.

If your modem and router are separate devices the modem resyncs to quick and the router won't have had time to pick up the new IP profile so you will need to turn router OFF and then ON wait 5 mins in the OFF position and check throughput again.

[Cloudane]

As a matter of interest, though it's connected at 46 now, speedtest.net is still returning the same throughput of 36 as before.

If your modem and router are separate devices the modem resyncs to quick and the router won't have had time to pick up the new IP profile so you will need to turn router OFF and then ON wait 5 mins in the OFF position and check throughput again.

Good point! But no, it had reconnected 7 hours ago.  I have just done so again and still have the same throughput. 

BT's test also says 36:

Download speedachieved during the test was - 36.75 Mbps
 For your connection, the acceptable range of speedsis 40 Mbps-44.97 Mbps .
 Additional Information:
 IP Profile for your line is - 44.97 Mbps

Upload speed achieved during the test was - 8.39Mbps
 Additional Information:
 Upstream Rate IP profile on your line is - 20 Mbps

After logging onto the test_domain thing it resulted in 40/2 and said it was performing poorly and to report a fault saying it failed at the 3rd test.

Speeds are back to 36/8 after reconnecting via normal login.

[WWWombat]

For clarity, I'm not personally saying you have got a Tap, but Wombat is pretty damned clued-up with these things. I'm just throwing my two'penneth in regarding what can and does happen in the network from Exchange to Home.

For clarity the other way around ... I'm good at deciphering the digital side of things, and all the statistics being sent back, and linking that back to likely causes ... but I'm definitely not so good at the nitty-gritty analogue stuff.

But this particular case looked like an obviously great, clear, example of what a bridge tap looks like on Hlog.

I don't think I'm £130-sure, though; not for a line already getting 70Mbps. I think I'd work out how to get an agent to run one of those diagnostic tests, i.e. what I'd need to be telling them (which probably doesn't mention the "bridged tap" phrase, or the Hlog graph) and get an engineer sent (free) on that basis. But I can't think of a symptom that would fit the bill...

[NewtronStar]

My understanding of this possible fee is if a fault is found on the CPE side the stuff after the master socket extensions wiring but excluding the BT Modem HG612 and ECI

You have to convince your ISP that there is a some kind of fault on your line don't ask directly for an OR appointment try and persuade your ISP during that call do you think this will require a OR engineer to visit my premises.

Of course they will tell you of the possible OR engineer fee but your ISP thinks you need an engineer so they will have to foot the bill if no fault found.