How does it work

I changed to BT Infinity on a Friday but due to a cock up I had no broadband, didn't get broadband until following Tuesday.
This was due to someone making the wrong connection in the cabinet.
Just so I can understand, can someone explain how the phone was changed to BT and worked o.k. but not the broadband when only one pair of wires deliver both.

Because beforehand the phone pair went from the exchange to the phone cabinet and from there to you.

With FTTC it goes from the exchange to the phone cabinet just the same, but is re-routed in there to the fibre cabinet, where the fibre signal is merged onto it. (The FTTC signal doesn't necessarily even come from your exchange). The result is routed back to the phone cabinet and in there is connected to the pair to your house.

What exactly happened I don't know, but maybe someone else's line was connected to your fibre and your line wasn't touched. The ADSLx would normally have continued working in that case so that probably isn't it. I'd need to think more, but that's how the circuit is constructed.

Edit - who was the line with before BT? That may give us a clue.

Edited by RobertoS (Tue 24-Mar-15 16:05:10)

Or to put it a little more simply - the phone connects in one cabinet, the broadband in another - someone messed up the broadband bit

Uh uh.

Nobody goes near the FTTC cabinet for FTTC installs. It's all done using the "patch panel"* installed in the PCP. He was told it was in the cabinet.

Perhaps the engineer connected to the wrong FTTC to/from coupling, instead of the one that would have the OP's feed at the other end. That would keep the phone working but with no fibre input.

* I don't know if that's what it is called in this scenario, but that's the function.

Agreed generally with what you have stated.

The question that arises in my mind - Is there a specific link/VDSL filter point (pre-) allocated remotely within the FTTC?

Presuming that some form of "multiplexing" is carried out in the FTTC (DSLAM?) to get all of the (present) VDSL subscribers connected both ways to the fibre run, does it matter which of the available, linked and filtered FTTC terminations that anyone is connected to?

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Edit
I wonder if the installer forgot the final action of cutting the two, original D-side lines in the PCP, thus short-circuiting the (new) links to and from the FTTC?

I wonder what effect that would have?

Edited by deleted (Tue 24-Mar-15 19:22:20)

There are individual ports on the DSLAM line cards per PCP connection. I seem to remember an engineer post on here that the installer is told which PCP port to use in order to link to the subscriber's FTTC headend connection. The implication being that the provision from the headend is to a specific port on a specific card.

These ports being hard-wired to the PCP at card installation time.

I'm not sure if that technically covers your question, but AIUI it is not up to the engineer just to connect using any he wishes.

In reply to a post by eckiedoo:

Edit
I wonder if the installer forgot the final action of cutting the two, original D-side lines in the PCP, thus short-circuiting the (new) links to and from the FTTC?

I wonder what effect that would have?

(This wasn't present when I started my previous post.)

I don't think that holds water. To connect to the patch panel there would need to be a link from both the exchange and premises pairs. If not the OP's then whose?

"I wonder if the installer forgot the final action of cutting the two, original D-side lines in the PCP, thus short-circuiting the (new) links to and from the FTTC?

I wonder what effect that would have?"

Assuming that the installer had actually carried out almost all of the work correctly, from locating the subscriber's correct D-line (17070), through connecting that pair correctly to the correct port in the FTTC - but simply forgot to do the "final snips", to ensure that the POTS is properly diverted to the FTTC and back - or to view it another way, that the POTS can still flow directly through the PCP to the subscriber, instead of being forced by the "final snips" to go via via the FTTC.

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My suspicions are that although the VDSL signal would still get to the subscriber, it would be attenuated to the degree that it would not be detected by the subscriber's modem.

In that situation, one pair of the FTTC links would be delivering the VDSL signal effectively without rejection filtering, to the E-side pair (including a very short length of the D-side in the PCP) to the Exchange.and the implied losses of the long length, particularly at the higher operational frequencies of VDSL.

Only experimentation or if someone has actually encountered the situation, might provide the answer.

Interesting.

Sorry, I don't understand (on a quickish read) that theory, and I don't know what this final snip is that seems to be the basis of it.

The existing E-side and D-side pairs start off connected. To connect either to the FTTC panel requires disconnecting them from each other.

Edited by RobertoS (Tue 24-Mar-15 20:46:24)

I am not an OR or BT engineer, but am trained in microelectronics.
"multiplexing" is used in the FTTC cab and then the resulting signal is sent back to the phone pair, and then to the home, but there might have been a fault in the multiplexing chip [on an input or output gate] that needed checking.?
Hence the delay.
The VDSL signal would not be getting to the home [at least not fully], because if the multiplexer was faulty it would be bottlenecking the circuit until fixed.
The delay was probably due to a circuit fault somewhere in the FTTC box even if not at the main multiplexer chip [or chips]

Edited by deleted (Wed 25-Mar-15 00:38:32)

I remember doing multiplexing in a BTEC Telecoms unit in the 80s as a student and its only just started to be deployed!

Multiplexing is still used today, in fact the modern [or even the old] PC`s still use it.
It is not just being deployed, it has always been a part of nearly all microelectronic systems.
The same could be said for high and low pass filters, transistors, inductors etc.
It`s just a recipe like cooking.
BTW I am 77, but still enjoy messing with a hot soldering iron.

Morning Robertos

Agreed that the original pair must be cut at some time during the operation, to achieve the diversion to the FTTC.

If they are cut at the start, then basically there would be no Voice Phone Service until the end of the operation, say a loss of about 5 minutes.

By leaving that "disconnecting them from each other" to the end, there is no interruption to the Voice Phone Service at any time.

-------------------

When I watched my own line being upgraded from ADSL to VDSL, in June 2014, arriving at the PCP just as the 17070 call was confirming that the technician had found my D-side pair correctly, he than selected the FTTC dual link pairs "some how" at the opposite top corner of the PCP - where I was standing to the right, the PCP right-hand side wall hid that area.

He ran two twisted pairs from that corner across to the left, to my D-side pair. Those two pairs were new "off the reel".

Again I did not see exactly how he connected to the FTTC "tails" because of the PCP side wall.

At this stage, there had been no interruption to part the E-side from my D-side.

He connected those two short pairs (say about 2 feet long) to my D-side, paired and colour to colour, about two inches apart, using Gel Crimps, so still no break in Phone Service.

Having done that, he then cut out each of those two inch lengths, thus effectively diverting the Exchange line out to the FTTC, merging in the VDSL signals; and returning to the PCP , then heading out to my house.

Tidied up the new, off-the-reel pairs etc to run across the inside of the top of the PCP; picked up the "two inch" fragments and some other odds and ends; and closed the cabinet.

That is, there was no break in the original, probably-1967 wiring, until the very last moment.


If I had been using the phone in my house, I doubt if I would have noticed any of the work apart from the 17070 call, as effectively there was no time when that continuity was interrupted.

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Hence as the original OP continued to have Phone Service, I suggested the possibility of the final cutting and thus diversion being omitted.


There is also the chance that the technician got the respective colour from pairs mixed up - although I am doubtful of that.

Morning Banger

"Multiplexing" was being used and taught back in the 1950s - and was far from new then.

Edited by deleted (Wed 25-Mar-15 07:18:20)

I don't know if that's what it is called in this scenario, but that's the function.

'FTTC ties' is the accepted parlance for those who work on them.

The question that arises in my mind - Is there a specific link/VDSL filter point (pre-) allocated remotely within the FTTC?

Yes ! When a customer orders an FTTC service, Openreach will allocate one of the ties from the FTTC DSLAM and build it's remote path to Btw/Sky/Talktalk.

So if the installer connects the punters voice service through an incorrect port then there is a good chance the punter will end up with no (internet) service at all. The filters will stop the original ADSL, and the wrong FTTC ties will give no sync/no PPP dependant on what it's current configuration is.

Not all the ties are live (produce sync) when not in use. I guess theres a slim chance that the punter has ordered through BT broadband, and then gets another BT Broadband configured tie, that'd work, but still would be technically incorrect.

As for the OP, without further details it's going to be hard to establish what the cause was ..... wrong ties, incorrectly built ties, faulty ties, incorrectly jumped ties ..... the list goes on.

Jeez, the installer made a meal of doing your line ! No wonder you seem a little confused

Find your E-side, cut down and verify the number, trace the jumper to the D-side (whilst doing this you can be verifying sync on your allocated ties) run a new jumper from the E to the FTTC in ties, check dial tone is coming out of the FTTC out ties, and jumper this to your recently discovered D side.

I'm not sure if that technically covers your question, but AIUI it is not up to the engineer just to connect using any he wishes.

Correct, you need to be doing an FTTP installation to have that luxury.

"Find your E-side, cut down and verify the number"
- He must have done that to get the correct number returned on his 17070 call, using temporary gel crimps to connect his Test Phone, without cutting/snipping any wires.


" trace the jumper to the D-side (whilst doing this you can be verifying sync on your allocated ties)"
- This may have been part of the operation hidden by the PCP side wall or panel.


"run a new jumper from the E to the FTTC in ties"
- First of the pair of the two new link pairs, taken fresh of the reel


"check dial tone is coming out of the FTTC out ties"
- This may have been part of the operation hidden by the PCP side wall or panel.


"and jumper this to your recently discovered D side."
- Second of the pair of the two new link pairs, taken fresh of the reel



Then finally cutting out the short 2 inch lengths, including his temporary connection, between the FTTC links.



He seems to have followed almost exactly what you describe, apart from leaving the "cut-down" to the last - thus maintaining basic Phone Services working continuously throughout the whole operation.

Thanks for all the interest shown, makes good reading!

For the record I was with Talktalk (no problems but I wanted fibre which only BT offered at the moment).

When the engineer connected his kit to my master socket he said there was no broadband signal at all.
Phone was swapped at 13:15 on Friday and existing broadband stopped working, I got text from BT at 15:50 saying all was up and running. Help line to foreign parts insisted that I wait until midnight despite the text message! Monday engineer appointment failed to turn up because it had not been passed to UK from India. Finally got it all working Tuesday p.m.

using temporary gel crimps to connect his Test Phone, without cutting/snipping any wires.

Read what you've typed !! How can that be ?? How can you use 'temporary gel crimps' to connect wires without cutting or snipping ???

A BT Technician demonstrated to me about 9 months back, a type that had a "pass-through" arrangement for one of the wires; so that it did not have to be cut, in that respect similar to the ones available for car wiring many years back.

He mentioned that he found them particularly useful.

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Page 3 of this "3M" PDF shows two such connectors, the lower, Green one being a very distinct possibility as it is generally similar to those used by OR/BT, as illustrated elsewhere in that PDF.


http://multimedia.3m.com/mws/media/447443O/3mtm-scot...


The Red one on Page 1 is identical to the simple, non-pass-through type that i have a sample of. Must try to get some more.

With this Red one, I wonder if folding the wire, "kirby-grip fashion", would also allow it to be used, without cutting the wire?

Unfortunately, I think that I have not got a suitable wire to try this approach.

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Edit added

The UG Green connector on Page 9, complete with little connection diagram appears to be a good illustration; and the slot to accomodate the uncut wire is clear at the far side --

http://www.cablejoints.co.uk/upload/3M_Scotchlok_Cri...

Edited by deleted (Wed 25-Mar-15 14:37:42)

Yeah, yeah ..... 'no break' crimps.

He mentioned that he found them particularly useful.

Not much of a 'technician' then. Anyone worth their salt knows these crimps are pants, HR faults aplenty.

Forgot to mention in original post, on checking phone charges I have been charged 24p for a four second call to a dedicated HMRC number at the time the change over was happening.
I never make calls in the day time prefer to use mobile minutes until the evening free time.
No one at my address made this call.

How bizarre ! This must be some form of billing cock-up.

Interesting that you are actually aware of them; and as the 3M maker states, that series is actually IDC (Insulation Displacement Connectors) rather than true (Compression) Crimps.

Fortunately, they were only used temporarily on my upgrade, to connect the Test Phone; being removed when the original wiring was cut and removed, as the last significant action of my upgrade.

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You mention "HR faults aplenty", I wonder why - possibly the straight through, "no breaks" wire is not included in the gelling action?

If they are only used for that short, "5 minute" installation period, then completely removed, the "HR" situation really does not have any relevance.

-----------------

Ooops, thinking further, I wonder if those UG connectors were used on my FTTC links, which might be the explanation of my recent brief connection losses losses, which Andrew suggests are probably HR in nature.

Thanks for stimulating that thought.

Another visit to the PCP when the opportunity arises!

Edited by deleted (Wed 25-Mar-15 15:46:00)

Yes I agree, been watching the call log and nothing further. Strange that it happened at the time of change over but can't see how that would have anything to do with it.
The HMRC number was for probate issues, I definitely don't have any need for that!

Interesting that you are actually aware of them; and as the 3M maker states, that series is actually IDC (Insulation Displacement Connectors) rather than true (Compression) Crimps.

They are supposed to used for joint remakes, removing blue beans and the like. They are fiddly to use and don't take properly.
That's why they don't get used very often, do it once, and do it right, rather than faff around with these blighters.

All the gel crimps used by Openreach are IDC.

I really can see no need at all to use them to connect a test phone.

wire is not included in the gelling action?

The 'gelling action' ???

The enclosed IDC connections terminate the wires, the gel bit refers to the gel inside which is to help prevent damp ingress.

And at 4 seconds in duration, of no use to anyone else either ???

Maybe a misdial of the Eclipse test number by the installer ?

Thank you, I am well aware of the reason for the gel, having been one of the first users in the electronics industry of silicones and silicone grease, particularly on UHT connectors back in the 1950s. Also back then I experimented with true crimp joints, including sectioning them for examination as to the effectiveness of that form of connection.


Obviously, not being the technician involved, I can only describe what I saw being used etc - and I have got extensive experience in the electronics industry.


I suspect that the slot in the side of the UG "gel crimps" with the wire running right through, is not sealed to the same degree as the simpler "crimps", thus suspect that the gel may not form fully around that wire and/or leak.

Also, not being fully enclosed/supported, the wire/s may be more open to disturbance by later accesses to the PCP etc.

The number dialled, which I can give because it is in the public domain, was
03001231072
Does that look like any that BT/OR would use, I am told they use 0800 ones.

Nope, that's nowhere near the Eclipse test number, as you say, it's on 0800 number.

How very odd.

https://www.gov.uk/government/organisations/hm-reven...

"
Telephone: 0300 123 1072
Outside UK: +44 300 123 1072
Get general advice and information about Probate and Inheritance Tax following a death
"

Yes I knew that, I mentioned it in an earlier post.

We have no reason to call that number. My house phones have dialled numbers saved in them for recall and it isn't there.
I shall put it down to a "glitch" and keep an eye on call log.

It is a shame that when you speak to BT Retail they say they are the only ones that can supply fibre, whereas that's very far from the truth, almost all ISPs can supply fibre including your prior ISP talk talk.

I hope they say they are the only ones that can supply "infinity" - which is technically true. People assume infinity = fibre - if they are saying they are the only ones with fibre then people told that can complain to ASA/Ofcom.

EDIT: The OP doesn't state why they believed only BT could supply and as someone else I think said it is possible TT can't currently provide as they may not yet have put their kit in the exchange.

EDIT2 : The OP does now state and I have responded to that additional info.

Edited by ian72 (Thu 26-Mar-15 15:55:11)

Had that been the case I would probably have stayed with TT.

The fibre in my area was with the Connecting Somerset and Devon thing which was done with BT.
TT could not say if or when they would be providing fibre in my town, I understand it would involve them or anyone else spending money to do this.

I was on TT LLU so thought they may have been able to provide the service but they were not able to at this time.

I made my order online so did not speak to anyone.
At no time did BT suggest to me that they were the only ones able to provide fibre

Because it is BT many other suppliers could have provided a service via the wholesale provision (it would have been BT underlying but people like Vivaciti and many others resell the BT wholesale solution).

TT and Sky put their own equipment in exchanges and may not be planning to do so in your exchange - but pretty much every other ISP (barring Virgin) could have provided a service over the BT wholesale network.

I was sending my reply at the time you were. See my reply to the other post.

I was sending my reply at the time you were. See my reply to the other post.

LOL - Ditto. We keep crossing over

Yep we do!
Only Sky and TT offer LLU from my exchange, so BT was the only option for fibre.

I think it was on this forum that someone said how much it costs another provider to give fibre in an area. A lot of money for what in effect is a bit of cable at the exchange, so may not be worth it in a small town.

You are still confused I think. BT wholesale provide the fibre. But, that does not mean you have to buy it from BT retail. Vivaciti and others resell those products.

I don't think so. At the moment only BT, Plusnet (BT) and John Lewis can provide at my exchange,that may change.
From what I understand TalkTalk who have LLU available at my exchange would need a data link cable to connect to their equipment. Open reach charge £2000 for this and so TT may decide it is not viable for them.

In reply to a post by Sylcol:

I don't think so. At the moment only BT, Plusnet (BT) and John Lewis can provide at my exchange,that may change.

Who told you that?

Only offers I got when looking to go for fibre,

You obviously didn't look very hard, there are many ISPs that will supply a BT Wholesale FTTC service.

Looked where?

Lots of sites only list the biggest providers.

I am sure you are right but don't think we have that much choice in TA24.

Some searches return results but when you actually try them they can't provide fibre.

Uswitch lists TalkTalk for instance but not available here as yet. Some others are too expensive.

I do realise that the offers are just to draw you in and will rise after the first 12 months or so.

don't think we have that much choice in TA24

You do. Rather than use sites such as uswitch which only list ISPs that pay them the most try instead checking with the individual ISPs.

Oh I have done that as well, selecting from those listed on this site for example.

All done now so with BT for next 12 Months for better or worse which is what started this thread in the first place!
I am aware of how comparison sites work.

So, out of interest, which ISPs did you try that said they were unable to supply an FTTC connection (excluding, of course, TT & Sky plus VM)?

Weren't there a few exchanges in the north of Scotland a few years ago, maybe even now, where only BT Consumer and maybe one other could provide ADSLx? The restriction being because they had paid for the exchange enablement?

The three the poster lists that he can get are all BT Group (ISP) companies

Those would be IPStream only exchanges and fibre is only available where WBC backhaul is available.

So full range of BT Wholesale based ISP should be available, the issue is the more price friendly alternates to the big 4 or 5 tend to rely on TalkTalk Wholesale so if they've not put the fibre link in yet, they won't be available yet.

I think the last post by Mr Saffron explains it all. TT do not have the link yet so the cheaper providers are not players at the moment.
I am only a home user and so was looking for a reasonable price with evening and weekend calls included. BT are offering good value at the moment but will of course increase after the first year.

This side post only started because it was suggested that BT had said they were the only ones who could provide fibre at my location. They did not say that.

I don't recall which others I checked now but I think they were costly in comparison.
I suppose that whoever I had chosen the connection would have been done by the same OR engineer or their contractor, and the same cockup would have resulted, hence my original question.