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Beginner
Posts: 5
Registered: ‎12-06-2012
0
Accepted Solution

BT Infinity Wiring Question

Hi All,

 

I've a technical question regarding the wiring of my BT Infinity - which was partially shredded by my dog at the 'Double Socket' (see below) and re-wired by myself.
I can't be 100% I have put it back the way the engineer had left it and was wondering if anyone knew what the likely configuration would have been.

 

The House is configured is as follows:

Phone Line [4 core? Haven't looked] -> Junction Box (JB)
Single 4 core cable -> Simple Socket (No real Master) - 2 Cores connected from JB to Pins 2/5, and the 6 core wired
Single 6 core cable -> Double Socket - When inspected after damage Blue pair bypassed this socket on to the the next one and the orange coming back were connected
Single 4 core cable -> BT 'Infinity' Socket
Data cable -> Modem

 

Now when the engineer came they obviously didn't want to move the master socket from the 1st floor to the ground floor, nor did they wish to run a data extension.
My best guess is that they used the Blue-White, White-Blue cores to run an unflitered line to the Infinity socket, and the the Orange-White, White-Orange cores back to the sockets as a filtered phone line.

 

The thing is, behind the 'Simple Socket' the Blue line is still connected to the socket, it doesn't bypass directly to the Infinty socket like the 'Double Socket' does. I assume this is so the master socket will always work if the line breaks anywhere internally (Otherwise it wouldn't be a master) Does this mean it requires a regular adsl filter on the phone though? Noone ever noticed any internet outages using this phone prior to my rewiring, but using it now does indeed kill the internet.

 

So it either needs a filter, or is it possible that returning the orange pair back to this socket again will stop this? (I don't think it will as the orange pair will be on 1/6 not 2/5 - line 1)
Does a normal filter work with Infinity? and did the engineer leave one on this phone (which I removed) because its unnecessary to remove them (which i read was standard practice), or because it was necessary to stop the internet going off when that phone is used.

 

Diagram to help understanding of the situation:

BT.PNG

 

Many thanks guys, just want to do as pro a job as I can putting this back together.

ypt
Aspiring Expert
Posts: 502
Registered: ‎02-08-2011

Re: BT Infinity Wiring Question

[ Edited ]

Hi Bob,

My experience is with what was described as a "Star" network, where the cable came into a junction box by the door - one downstairs socket  - one upstairs socket - both fed by own cable from JB.

All the openreaach guy did was fit a new infinity faceplate to the downstairs socket.

Using the upstairs phone, disconnected infinity!

At the time (Oct last year) I was advised to fit a filter upstairs - this prevented the disconnections, but the profile still started dropping.

Second openreach guy changed the modem - didn't make any difference

Third guy who announced himself as a "telephone engineer" came and rewired the junction box and the master socket, so that upstairs was fed from the filtered  (back) side of the master socket. Touch wood now a stable connection.

 

Summing up:-

1) you should not need to use a filter.

2) your wiring is not quite right - I am not a telephone technician - it looks as if the simple socket is fed from the incoming supply - your second socket is fed back from the infinity socket (which I think is/should now be the master socket) - there has been a discussion on the forum where some BT employees have been disciplined for "wiring back" - so really not too sure where that puts you - if you call them back in it might cost you £130 "doggy cost".

3) the infinity socket should always be the master.

 

Hope this helps - maybe a more techie person may be able to help.

Michael

Expert
Posts: 1,724
Registered: ‎08-04-2011

Re: BT Infinity Wiring Question

Easiest thing to do is if you have gel crimps, make sure the blue pair of wires is all crimpped together to ensure its the only one connected to the infinity socket, then connect your other sockets to the orange pair using the extension frontplate of the infinity socket.

Beginner
Posts: 5
Registered: ‎12-06-2012
0

Re: BT Infinity Wiring Question

Thanks Michael, considering I have gotten it working, and can easily make changes myself I probably wont bother with the potential hassle of getting BT back out - even if they haven't wired the place up to best practice!

 

Really the question to pose now is, can I just use the regular ADSL filter at the 'Master' socket, or will this affect the speeds I'm receiving. I've got to assume you cannot just use an ADSL filter, otherwise why would BT go to the effort of coming out to fit this socket for you.

 

My first speed test (albeit over wifi) told me I'm only receiving close to my minimal potential speed.

 Download speedachieved during the test was - 16.95 Mbps  For your connection, the acceptable range of speedsis 12 Mbps-38.72 Mbps .  Additional Information:  IP Profile for your line is - 38.72 Mbps

 

I will rerun from a wired connection but it doesn't look too good. The ping was 33ms though, which I didn't think was too bad.

 

Deathtrap3000 that is what the original engineer did, there were two 3M gels in the Double socket sending the blue pair on to the infinity socket. However if I send the orange pair back to the very first socket and use those for the line any failure inside the home will cause the master socket to fail also! Which could one day be an issue if I'm not about to fix it quick. Though I suppose the risk is minute, so if the ADSL filter is not a viable solution I will pop out to get some gel crimps and have the orange pair sending a filtered line back to each socket the unfiltered line has already passed.

ypt
Aspiring Expert
Posts: 502
Registered: ‎02-08-2011

Re: BT Infinity Wiring Question

Hi Bob,

 

You shouldn't need to use the old filters, this with the "old" master being in circuit before the "new" master may well have dragged your speed down - although for wireless wasn't as bad as some on the forum. The one consolation is that your profile is still high.

 

I think Deathtrap is right in that you need to by pass the "old" socket and feed back to it - all slave sockets must be fed out of the back of the "new" infinity master socket.

 

Please note my technical ability is not in telephone wiring, and any advice is given with all the usual caveats!!!

 

Michael

 

 

Beginner
Posts: 5
Registered: ‎12-06-2012
0

Re: BT Infinity Wiring Question

[ Edited ]

You're totally right in saying I shouldn't need to have a filter, but from what I remember the engineer did infact leave a filter plugged into the first socket which is still receiving an unfiltered line - on purpose or not, I don't know, but I do know that without the filter, the internet will disconnect if the phone is picked up. Also I don't if the with filter, the internet speed compromised. Infact, is the internet speed compromised by the entire setup itself?! Probably.

 

So the technical question is whether this filter is a suitable solution, or if I should go ahead and wire the 'Master socket' the same as the 'double socket' that the engineer altered.

 

Many thanks

 

[Edit]

Sorry Michael I must have skim-read your post! Missed the part where you agreed with Deathtrap3000. I do agree there too, it appears to be the only solution, I'm just trying to figure out what the engineer was thinking at the time of install and whether a mistake was made not sending the filtered feed back to the old master, or whether it was left purposely like that with a filter on it so that it would still operate if there were a break anywhere else internally.

ypt
Aspiring Expert
Posts: 502
Registered: ‎02-08-2011
0

Re: BT Infinity Wiring Question

Hi Bob Sorry about lack of formatting -- using horrible apple thingy!!!!! I realize now why BT are twitchy about wiring back --- in the olden days, first phone direct to download to house -- fault on phone would be probably down to BT. Now with lots of customer wiring, a break in the cable would be down to ???? To repair. But I think that you need to go down the way we've discussed rewire and remove the filter -- at least if it doesn't work you can always go back to how it was. Michael ---- Good Luck
Beginner
Posts: 5
Registered: ‎12-06-2012
0

Re: BT Infinity Wiring Question

I finally sorted this out after harrasing an Open Reach engineer in the street (I kept seeing them about and managed to bump into one outside work)

 

He gave the same solution as you guys here as well as some gel crimps from his van (which is really the only reason I didn't just do this anyway - hadn't found time to buy the bits), so I've implemented the solution today and seen immediate improvements in ping and slightly in speed - although BTs speed tester just wont work for me for some reason so I can't be completely sure.

 

Thanks for all the responses here

Beginner
Posts: 5
Registered: ‎12-06-2012
0

Re: BT Infinity Wiring Question

Used the BT Wholesale speed tester and yes this has definitely improved things - upload hasn't changed much but is still respectable.

 

 Download speedachieved during the test was - 37.15 Mbps
 For your connection, the acceptable range of speedsis 12 Mbps-38.71 Mbps .
 Additional Information:
 IP Profile for your line is - 38.71 Mbps

Upload speed achieved during the test was - 7.23Mbps
 Additional Information:
 Upstream Rate IP profile on your line is - 10 Mbps

Guru
Posts: 2,753
Registered: ‎21-06-2012
0

Re: BT Infinity Wiring Question

[ Edited ]

Try this to fix speedtest:

 

One way to apply this patch is:

  1. stop your browser
  2. make sure no Java running
  3. go to the Java control panel
  4. Java tab
  5. View ...
  6. insert -Djava.net.preferIPv4Stack=true under Runtime Parameters
  7. close View and java control panel
  8. restart browser and try speedtest

More details on thread http://community.bt.com/t5/BT-Infinity/Warning-java-7-and-BT-speedtest/m-p/558115/highlight/true#M52...