Bridge Tap?

Hi all.

Back again with a quick question or two.

My Infinity 2 connection is finally stable (mostly), but a quick check on my number in the Wholesale checker brought up some extra info. Wondering if I should be calling in to BT to get it looked at?

VDSL Range A (Clean) 80 60.7 20 19 55 Available
VDSL Range B (Impacted) 69.5 39.8 20 13.3 32.4 Available

Bridge Tap Y
VRI N
NTEFaceplate N
Last Test Date 18-05-2017

The Bridge Tap from what I've been reading about is ideally a N? But mines listed as Y, so wondering if I should get BT to have a look at that and get that sorted? There's nothing within the household that separates out from the main wiring, so I'd imagine that's somewhere else along the line.

Also, my stats are showing that I can gain higher speeds, but something is amiss (probably banding?), as I only max out at 57. So should I also call in to BT regarding both matters at the same time?

6. Data rate: 19978 / 57362
7. Maximum data rate: 30090 / 71518
8. Noise margin: 11.7 / 9.0
9. Line attenuation: 16.8 / 15.1
10. Signal attenuation: 16.5 / 15.1

Thanks all.

J1NG

:: edit ::

Just to add a bit more info, my line connection won't ever breach the 59 barrier anymore (55 top speed via thinkbroadband test). Whereas previously it would slowly increase again. Banded profile I'm guessing? The last phone engineer (not OR Broadband Engineer, just Phone Engineer) resolved an issue on the junction box down the line but didn't reset the line. Should I/Can I call BT up about this to get OR to reset the line? As the stats suggest I could get more, there's a tap, and (I think) a DLM reset request might be needed. Thoughts?

Edited by J1NG (Fri 11-Aug-17 09:30:28)

What phone wiring do you have in the home and how/where is the modem connected?

Standard phone wiring.

Main line from BT comes in straight to a MK3 plate. From there, a 0.5m phone cable to phone and 0.5m cable to HH5a.

Other devices connect to the HH5a. Nothing else touches the phone line.

:: edit ::

We also had a secondary line a long time ago, but it was shut down a while ago, and connects to the box outside:

So something like this:-

------ Current line (inside house) --- mk3 --- HH5a --- All devices
|
Box outside ---- off to rest of BT network
|
------ secondary line (inside house) --- old nte Faceplate

Could that be the tap in question?

:: edit again ::

The secondary line was it's own line, had it's own phone number, etc. This was back when 56k modems were required and mobiles were not as common, so like 1998-2000. Line was shut down in 2008 after no longer needing it. It was also quiet as a mouse unlike our main line originally (before the recent fixes).

Edited by J1NG (Fri 11-Aug-17 10:31:17)

Here's a document that describes what a bridged tap is and how to detect one http://www.viavisolutions.com/fr-fr/literature/smart...

574Mbps with a max of 71.5 initially looks a little low. However, the 9dB margin is 3dB higher than usual which suggest there are occasional noise or loss of sync issues on the line which has resulted in DLM setting the higher margin. As a rule of thumb, at higher speeds 3dB could be worth around 11-12 Mbps and that would push you up to around 69 Mbps - not far from max attainable. And with 57362kbps - almost certainly NOT banded. They tend to be xx000 sync rates (or just below xx998 ...).

As for the bridge tap - given your speeds, would BT do anything? It "may" be acting as a tuned aerial an picking up noise for example and that could be the reason you have lost a little. I very much doubt you would get BT to even investigate. Just make sure all your wiring is teh best it can be and there are no additional noise sources close to the modem.

The occasional noise and sync issues were from prior (a few months ago) when I would DC every few minutes even. This was traced to the junction box some 30m away where the phone engineer replaced the wiring there, but did note that the box covering was totally missing for that area, exposing all the wires. Since that fix, the line no longer has any obvious noise or sync issues.

The line previously was giving 69-72 (maximum back a few years ago when I was the first to get it), and slowly went down to mid 60's after the large amount of sync and noise issues. (None of which was internal to the house). The last fix (back in April/May) the speed went down again, but was not reset as the engineer was a phone engineer only. So wondering if not a call out for the tap, would a call for an OR Speed Boost engineer to reset the DLM be worthy?

Oh, and the line stats have changed again:

6. Data rate: 19978 / 57362
7. Maximum data rate: 29981 / 74188
8. Noise margin: 11.7 / 9.7
9. Line attenuation: 16.8 / 15.1
10. Signal attenuation: 16.6 / 15.1

Starting to look more like how I originally had the line a few years back. But the data rate itself remains stuck at the 57 region (which was previously 58 only a few days ago before the HH5a update which knocked the connection out a bit and DLM stepped in further). Which is why I feel it may be DLM related at least if not banded (especially since the DLM only goes down, never up anymore, whereas it used to a long while ago. Over 18 months ago when I first got on this lines case).

I had previously (more than 12 months ago when I had the speed boost engineer turn up) managed to get BT to send an engineer after they ran a speed test and found it below what they expected. Would I likely be able to do the same this time? Considering that there's a Bridge Tap somewhere and that normally if I'm not mistaken sends me down to the impacted line level?

Thoughts?

J1NG

The accuracy of the BT Wholesale Bridge Tap flag is a big unknown, so there may or may not be a bridge tap. The Openreach network is meant to be built such that there is none in the area of their responsibility.

As for DLM never going up anymore, its strange that we are still seeing the averages for Huawei cabinets with tweaks DLM can use still showing averages going up over time, less than in the past but still if DLM only ever dropped speeds we'd see a long term trend downwards.

I see. So I really shouldn't be putting too much into the Wholesale tracker thing for now since the certainty level is essentially unknown.

Regarding DLM, never going up anymore, I am not making a general statement for everyone, only on the line I have right now.

It's been a few months since the line was fixed, and it has never once tried to increase the speed. Even though the HH5a only reconnects again after the .mobi check every 2 weeks from BT. But as soon as the update for the HH5a recently happened (causing DC), the speed goes down further? Seems unusually quick drop speeds to me. Whilst never once trying to push it back up.

Prior to a few months ago, it would increase on it's own every so often, but not since May (when the last engineer turned up after the crazy amount of DC happening). Could the DLM be stuck?

J1NG

A lot of your problems may be because of the recent firmware update to the HH5A which is causing all sorts of issues. I believe BT are doing some "live testing" on the HH5A to try and improve G.Inp and DLM.
One possible solution is to replace the HH5A with a good independent modem/router.

Edited by deleted (Fri 11-Aug-17 11:25:47)

Any recommendations on the modem/router? Anything that will support gfast? May jump to gfast on deployment and would prefer not to have to change devices again.

Although back to the DLM and HH5a firmware... Considering that there was 2 months for DLM to do something with the older firmware before it was released and it still did nothing. I'm (logically) more inclined to blame DLM at the very least for the speed not being what it might potentially be.

J1NG