FTTC/VDSL with microfilters rather than faceplate

Hi -

I have a line with star-wiring (junction box terminating dropwire outside the house - two sockets wired off that via external wiring that go in two different directions). I have ADSL2 running reasonably well (10Mbps).

Is VDSL using microfilters rather than a faceplate a viable option? As there is no true master socket and therefore an ambiguous demarcation line I'm wary of replacing one of the sockets with an NTE5 box myself.

It will work, but is far from ideal.

Having this issue sorted (properly) now will pay dividends for both your ADSL , and even more for your VDSL service.

Not be tempted to bodge it, have your current ISP cause an SFI task, have Openreach come and sort it, leaving you with a true NTE and SSFP.

Presumably they charge for 'remedying' this situation ? And how do I get a SFI task opened? Is it easiest to order VDSL and then complain about the performance?

If there is a wire that goes in a different direction before your router (modem) then you may get reflections which reduce the quality of the signal going to the router. The wire is called a bridge tap.

You could replace the socket that your router is attached to with a modern master socket with filtered face plate, then run a cable from that master socket to your other phone point. You should make sure that the other phone socket is not a master socket with a capacitor and resistor. Changing the master socket is something you should ask your phone supplier to arrange. -

In this case (having looked inside both sockets) both are of the 'master socket' type's (LJs) with capacitors and resistors inside (though because of star wiring neither are master sockets in the traditional demarcation sense). One running downstairs and the other upstairs. I currently have microfilters connected to both, with the telephone downstairs and the modem upstairs.

The question about ordering VDSL first was around avoiding the call out charge for raising an SFI.

In reply to a post by chrisstiles:

In this case (having looked inside both sockets) both are of the 'master socket' type's (LJs) with capacitors and resistors inside (though because of star wiring neither are master sockets in the traditional demarcation sense). One running downstairs and the other upstairs. I currently have microfilters connected to both, with the telephone downstairs and the modem upstairs.

The question about ordering VDSL first was around avoiding the call out charge for raising an SFI.

I think you mean master sockets in the modern sense! You can have two sockets with capacitors and resistors but three will cause problems. You might find that one socket has the capacitor and resistor disconnected. The bits you need for a DIY approach are available on ebay and Solwise.

Star wired properties are not uncommon IME.

If there are two pairs in the wire from the junction box, you can use them to rectify the situation:

* outside line --> junction box --> pair 1 to master socket
* pair 2 (filtered extension) goes back to junction box
* connect this (separately) to the link to the extension socket

BT did something like this for me when I had FTTC installed at a previous house. The master socket was by the front door but there was no power socket anywhere nearby for a router. However, the cable to the living room extension had two pairs. So they took the "outside" line through one pair, put the master socket in the living room, and used the other pair back to the front door socket (from which the other extensions also ran)

It's certainly worth getting this rectified professionally though.

In reply to a post by Michael_Chare:

I think you mean master sockets in the modern sense!

Yes, I suppose I do really!

In reply to a post by Michael_Chare:

You can have two sockets with capacitors and resistors but three will cause problems.

Presumably this is to do with total capacitance on the line (which are effectively one really long piece of dead wire connected to the junction).

In reply to a post by candlerb:

If there are two pairs in the wire from the junction box, you can use them to rectify the situation:

* outside line --> junction box --> pair 1 to master socket
* pair 2 (filtered extension) goes back to junction box
* connect this (separately) to the link to the extension socket

Actually this isn't a bad idea (though can also see the value in having it done professionally).

If you have no true master socket, isn't it free to get one fitted?

The OP appears to have two though. So it sounds like some DIY has gone on, and I expect it's a chargeable job to sort it.

Quite possible, perhaps it would be best if he posted pictures of them.

In reply to a post by R0NSKI:

If you have no true master socket, isn't it free to get one fitted?

What was installed was old style star wiring which was never remedied (it looks like at one point it was free to have this remedied by BT but this is no longer the case). Because they are star wired, both sockets are identical so there's no master/slave relationship.

At some point the individual sockets have been modernised (from the looks of things sometime in the 80s), the style of wiring and type of sockets used seem to indicate that this was change performed by a BT engineer.

I'll post pictures of the junction box this weekend.

Edited by deleted (Thu 21-Mar-19 12:16:43)

An Openreach engineer would not have left two master sockets, even of an old type, on the same line. Nor would they have installed such a setup in the first place.

In reply to a post by RobertoS:

An Openreach engineer would not have left two master sockets, even of an old type, on the same line. Nor would they have installed such a setup in the first place.

I suspect this pre-dates openreach. I also suspect this was the standard manner in which star wiring (which implies multiple sockets) would have been connected, and presumably each socket (at the end of an independent spur) would have required a capacitor so that it would work with old style phones.

Edited by deleted (Thu 21-Mar-19 12:41:26)

A BT engineer in the days before Openreach existed became an Openreach engineer. Leavers and deaths excepted. (Oh - and promotions out of harm's way! )

Assuming you are talking about LJ-type sockets, no. AIUI there should still be only one master on the line.

In reply to a post by RobertoS:

Assuming you are talking about LJ-type sockets, no. AIUI there should still be only one master on the line.

Okay, I assumed the capacitor was there to pass the variable ring current up to the connected phone, while blocking the dc current.

In this case there are two independent spurs off the junction box - so would have assumed the socket on each spur would require a capacitor - anyway, will try and take photos of the insides of both sockets and the external junction box and post them here.

It probably depends on how many wires go from the junction box to each socket. Two would I suppose work in the way you say. Three should have T3 > junction box > T3 at the other socket, and I think that would work my way.

So this is a picture of the junction box outside the house:

https://ibb.co/KxX7GN4

The two greyish wires lead are the ones that lead to the sockets - they are of identical vintage, and are stapled to the wall, the one leading upstairs goes up the outside the house before going directly through the wall to a LJU. Both LJUs look like this:

https://ibb.co/HN6MJ6q

and like this inside:

https://ibb.co/GxM76cb

The only modification's I've made was to disconnect pins 3 and 4 (orange and green respectively).

Incidentally, I've now had VDSL activated on the line, and am currently getting 15.358 Mb/s / 5.075 Mb/s

I'm sure I'd get better rates with modern wiring, but suspect most of the benefit would be from having proper twisted pair rather than old style solid core, and the elimination of various extraneous bits of wiring between the filters and the socket, with the inbuilt filter playing a relatively minor role (the price point of an NTE5 is in the same ballpark as a decent standalone filter -- and so I don't assume the quality of the electronics is going to be a whole lot different).

In reply to a post by chrisstiles:

In this case there are two independent spurs off the junction box - so would have assumed the socket on each spur would require a capacitor - anyway, will try and take photos of the insides of both sockets and the external junction box and post them here.

I think that was how my house was wired. Creates an interesting situation if you have a fault as you can argue both legs are BTs. The correct way is to use 3 wires between the master and the slave sockets. Most modern phones do not use this third wire.

In reply to a post by chrisstiles:

The only modification's I've made was to disconnect pins 3 and 4 (orange and green respectively).

Incidentally, I've now had VDSL activated on the line, and am currently getting 15.358 Mb/s / 5.075 Mb/s

I'm sure I'd get better rates with modern wiring, but suspect most of the benefit would be from having proper twisted pair rather than old style solid core, and the elimination of various extraneous bits of wiring between the filters and the socket, with the inbuilt filter playing a relatively minor role (the price point of an NTE5 is in the same ballpark as a decent standalone filter -- and so I don't assume the quality of the electronics is going to be a whole lot different).

Having a spur before the VDSL modem is not good practice as you get reflections which will interfere with the signal. If you disconnect the other spur from the junction box you could find out what improvement that gives. You could then decide what to do next!

Edited by Michael_Chare (Fri 22-Mar-19 16:47:02)

In reply to a post by Michael_Chare:

Having a spur before the VDSL modem is not good practice as you get reflections which will interfere with the signal. If you disconnect the other spur from the junction box you could find out what improvement that gives. You could then decide what to do next!

Yes, though as by any interpretation its within BTs 'demarcation' I'm somewhat loath to make changes there myself, do you know where I can find images of the inside of that external box ? If I knew what was inside and what I was likely to have to deal with I'd give it a go.

Edited by deleted (Fri 22-Mar-19 19:32:06)

Something like This.
Might not have the screw terminals, just crimps

In reply to a post by witchunt:

Something like This

�Don�t worry Sir, I think I�ve found the fault. �

In reply to a post by chrisstiles:

If I knew what was inside and what I was likely to have to deal with I'd give it a go.

Judging by the first picture, I'd say moths, caterpillars, spiders...

In reply to a post by Zarjaz:

In reply to a post by witchunt:

Something like This

�Don�t worry Sir, I think I�ve found the fault. �

Well quite .. i was trying to avoid that.

In reply to a post by candlerb:

In reply to a post by chrisstiles:

If I knew what was inside and what I was likely to have to deal with I'd give it a go.

Judging by the first picture, I'd say moths, caterpillars, spiders...

Yeah, had a look inside, and the wiring is jelly crimped rather than a junction box - so i'll need some of those if I want to take one of the wires out.

The large slug inside was a surprise though - presumably it had grown in the box.

Do you need both sockets?

If not I'd be very tempted to just get some wire snips and "accidentally" cut the the one you don't need close to the crimps.

If you do need it then ideally you'd need to rewire the second socket inside from the a single master socket anyway.

Edited by alexatkin (Mon 25-Mar-19 02:30:10)

In reply to a post by alexatkin:

Do you need both sockets?

If not I'd be very tempted to just get some wire snips and "accidentally" cut the the one you don't need close to the crimps.

If you do need it then ideally you'd need to rewire the second socket inside from the a single master socket anyway.

Yeah, this is the second choice after using the crimps - the main goal being to keep things in a state that avoids repercussions with OR should I ever need work done on my line.

The main reason I brought the crimps up is that they are - as I understand - a fairly recentish thing (I moved in around 5 years back), certainly within the timeframe when ADSL was prevalent and star wiring was a bad idea, and yet someone who was presumably from OR has done work on the property and not remedied the wiring (I assume they must have told the pensioner who was the previous resident that they'd lose their extension).

Edited by deleted (Mon 25-Mar-19 11:44:46)

In reply to a post by chrisstiles:

Yeah, this is the second choice after using the crimps - the main goal being to keep things in a state that avoids repercussions with OR should I ever need work done on my line.

I very much doubt an Openreach engineer would recrimp the joint if asked to remove one of the extensions. They would just cut the wires close to the crimp. Note if you have recently moved in you can just plead ignorance and blame the previous occupants

If you do decide to go down recrimping the joint, which is probably what I would do, then while the crimps are cheap, couple of quid on eBay for 10, you will need to spend ~£10 on a pair of proper jelly crimp pliers too. You could use normal pliers but the teeth will leave marks on the crimps making it obviously a DIY job.

As a postscript, I thought people here might find the resolution to this both informative and amusing.

I raised a fault against landline quality against my ISP (to be fair there was some constant low level crackling on the line), after a number of line tests they finally diagnosed a ... bridge tap (which of course is star wiring by any other name -- but they had more or less signalled that they were unlikely to deal with star wiring itself)

An engineer was duly dispatched and he regularised both sockets, disconnected one socket and reconnected it as an extension, and attached appropriate faceplates. As it was in resolution of a line fault, it came in at no charge.

chrisstiles

What did you speed go up to after the corrections were complete? It is always good to know what performance improvements take place when wiring is corrected.

. bridge tap (which of course is star wiring by any other name --

Except that isn�t 100% true.

Extension wiring connected to an NTE will be detected as a bridge tap too.

What did you speed go up to after the corrections were complete?

It went from syncing at 14Mb/s down and anything between 1 and 4 Mb/s Up to 29Mb/s down and 7 Mb/s up.

Except that isn�t 100% true.

Extension wiring connected to an NTE will be detected as a bridge tap too.

Yeah fair enough -- except in this case what they were detecting was the star wiring.