Kitz Forum

Broadband Related => Telephony Wiring + Equipment => Topic started by: renluop on August 08, 2017, 02:04:35 PM

Title: Nosing in BT Wholesale ADSL checker found something!
Post by: renluop on August 08, 2017, 02:04:35 PM
I say 'nosing' because the line is not mine, but a relative's. I just wanted to see what FTTC speed they could get.
Top is the full 80, and they have been on fibre for a year or so with their provider. I saw that a bridge tap is registered at the last test date in May 2107.

The landline phone service is not necessarily affected by the fault, but assuming that the fault developed after they changed to VDSL, what obligation does BT Openreach have to rectify it, should it be reported, seeing that as a deterioration of service? I am not sure, if phone is with BT and FTTC with ANOR or if they have a combined contract with ANOR
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: gt94sss2 on August 08, 2017, 02:23:01 PM
The first thing to do is check your relatives internal wiring to confirm the bridge tap isn't an internal issue.  Then, you would need to check what speed xDSL they actually sync at and what speed package they have signed up too..
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: renluop on August 08, 2017, 04:07:52 PM
I take all that in, but all that out of the way, is the statement in the checker per se, even though the connection sync may be above the clean Hand Back threshold, a valid reason to ask for the fault's correction?
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: Black Sheep on August 08, 2017, 04:16:27 PM
Bone of contention is this topic with us, at the moment. Not something I can go into, either.

However, a bridged-tap will normally see a degradation of service and normally the ISP will report this to OR, and we go round to fix it.
Who pays for this service, we don't get to see ......... but IMHO it should be the ISP, as if the EU had been offered a 'Managed Install' when placing the order, the bridged-tap would have been identified immediately and removed.

However, it seems 'Self installs' have taken over the UK for the last 12months.
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: kitz on August 09, 2017, 11:10:12 AM
A thought occurs.   The bridge tap on there will likely have been picked up by the equivalent of a hlog from line data which it may be possible to view using DSLstats and a compatible modem.
As mentioned the bridge tap could very possibly be on internal wiring. Does the property have an NTE?  If not it and it has has star wiring then may be possible to ask for normalisation free of charge.   
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: ejs on August 09, 2017, 08:13:22 PM
I've never found anything official about any free "normalisation". Some of the official BT contracts (between BT and the CP) seem to imply that the "Network Termination Point" can be pretty much wherever and whatever BT like e.g. "the point at which the network cable arrives on the exterior of the Premises but no higher than 1.5 m above ground level".

If you tell Plusnet that you don't have a modern master socket, they'll probably tell you to "get an electrician to do it" or it'll be £160 done as a master socket move.

Most likely, the bridge tap will be due to using plug-in microfilters on each extension socket, in which case the extension wiring is the bridge tap. Just sort it out yourself if it's due to internal wiring.
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: renluop on August 09, 2017, 10:10:25 PM
Internal wiring has been mentioned as a potential source of the bridged-tap. As my information came from the BT Wholesale ADSL checker, surely it would only be looking at the wiring up to the  BT - EU demarcation point. Wouldn't it?
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: burakkucat on August 09, 2017, 10:37:32 PM
As electricity is the flow of electrons in a metallic conductor, how would the "BT Wholesale ADSL checker" instruct those electrons to stop flowing at the Openreach Network Termination Point (NTP)?  :-X
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: j0hn on August 09, 2017, 10:39:00 PM
It's not that clever. A large % of bridge taps are down to the internal wiring. That's why it has been suggested to check that before contacting the ISP.

If unsure, you could photograph (or ask your relative to) all the sockets internal wiring and post that here. I'm sure advise would be given on how to rectify it.
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: jelv on August 09, 2017, 10:41:05 PM
It is looking at the line towards you - it has no way of stopping at the demarcation point. It's not like a ping where it progressively looks at each hop. Stopping at the demarcation point would only happen if it tested the line with everything your side of the demarcation point disconnected - including any extensions.
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: renluop on August 09, 2017, 11:16:44 PM
 don't mind being ignorant. Only ignorant people learn, like only dirty people wash! ;D
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: ejs on August 10, 2017, 04:18:11 AM
Bridge taps are only detected when you have a live FTTC service on the line, because they are detected using the HLog data supplied by your VDSL2 modem.

If you have ADSL, it'll show as U for unknown. The bridge tap is still there, and the wiring would not be optimal, but the length of the bridge taps caused by internal wiring does not have such a significant effect on ADSL frequencies as it does for the higher VDSL2 frequencies.
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: jelv on August 10, 2017, 08:05:25 AM
I'm going to ask my own related question: How does it know if you have a NTEFaceplate?

I was also wondered what VRI was but managed to find http://www.ispreview.co.uk/index.php/2017/07/bt-wholesale-broadband-checker-adds-options-vri-ntefaceplate.html which answered the question.
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: Dray on August 10, 2017, 08:17:54 AM
Bridge taps are only detected when you have a live FTTC service on the line, because they are detected using the HLog data supplied by your VDSL2 modem.
so does that mean that dslstats could detect a bridge tap also?
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: roseway on August 10, 2017, 09:37:08 AM
It's easy enough to see a DSL-affecting bridge tap by looking at the HLog graph, but I'm not sure about getting DSLstats to detect this automatically. See http://www.viavisolutions.com/fr-fr/literature/smartclass-tps-detecting-bridged-tap-and-noise-interference-application-notes.pdf for a fairly clear description of this and a couple of other factors.
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: renluop on August 10, 2017, 10:01:33 AM
having read the comments in the ISP Review article about inaccuracies, I'm tempted to treat my find like a sleeping dog.
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: Dray on August 10, 2017, 10:20:22 AM
That description looks a bit hard to implement but always nice to see how close DSLstats actually is to official test equipment documentation :)
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: ejs on August 10, 2017, 04:33:15 PM
I'm going to ask my own related question: How does it know if you have a NTEFaceplate?

I don't know exactly how it works, but it's mentioned in BT STIN 517 (SOGEA).
Quote
3.2.9 SOGEA Faceplate
SOGEA front-plates may contain passive electrical signatures that will allow Openreach to
determine which type of SOGEA face-plate is attached to the circuit. These circuits do not
change the electrical poperties of the line as defined in SIN349 [3].

The VRI and NTEFaceplate items in the checker are probably so that ISPs can determine if a line is ready for SOGEA or if they would need to send someone to fit an NTE5C and faceplate. Probably not so much about checking if you have the latest and greatest faceplate for your xDSL service.

The Bridge Tap item was added slightly earlier than the SOGEA items.
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: kitz on August 12, 2017, 10:59:57 AM
As my information came from the BT Wholesale ADSL checker, surely it would only be looking at the wiring up to the  BT - EU demarcation point. Wouldn't it?

As per my post above,  its identified by looking at the same data which is used for hlog graph.

A thought occurs.   The bridge tap on there will likely have been picked up by the equivalent of a hlog from line data, which [means] it may be possible to view using DSLstats and a compatible modem.

Not always easy to spot though unless its quite sharp or repetitive.  From the graph we have to use our eyes looking for variances.  If you have the raw data before its graphed, then it would be possible to specifically look and analyse for variances of more than 'x'dB within a certain range of tones.
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: aesmith on October 18, 2017, 02:59:23 PM
I'm going to ask my own related question: How does it know if you have a NTEFaceplate?
It doesn't as my line at home (new curvy faceplate), and our FTTC in the office (Mk3) both show as "--".  Could it be that it's populated from OR test or visit reports, so only shown for lines where this has happened recently? 
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: smf22 on October 18, 2017, 05:05:46 PM
Could it be that it's populated from OR test or visit reports, so only shown for lines where this has happened recently? 

If it is populated once Openreach have visited, the results are not updated very often. I had an engineer round on 05-Sep and he swapped me to the new face plate... yet I'm still showing "--" on the checker.
Title: Re: Nosing in BT Wholesale ADSL checker found something!
Post by: renluop on October 18, 2017, 06:04:24 PM
Reverting to my OP, I mentioned elsewhere that the extra info for the likes of bridge taps has been removed for various lines, but not everywhere. I cannot think, if it is doubted, why it hasn't been removed throughout.

More education for ren needed?