Slow downstream after BT line fault

[MartinL]

I recently found my BT line was very noisy and intermittent (hissing and crackling on line). On plugging a phone into the master socket I found the noise was present there.

A BT Engineer visited and told me the cable was the very old grey thing cable which was prone to insulation break down and corrosion of the wires, which was causing this fault. He replaced the whole cable from the master socket to the telegraph pole in the street. He tested the line and confirmed it was working as expected. The telephone line how not lost its previous noise.

The only problem I have now is the ADSL seems to be connecting a lot slower than it was previously. At some time in the past I recall it was regularly connecting at 2-3Mb which correlated with the SKY site (suggests 2-3Mb). I checked on DSL ZoneUK - Broadband checker and it tells me I'm 2.49Km from the Exchange.

The SKY ADSL router is connected to an extension socket which is run from the master socket under the lounge floor (avoiding electrical cables).

I checked the ADSL router connected to both the extension socket (with microfilter) and the master socket (with microfilter) by removing the faceplate off the master socket and plugging into the BT socket.

The stats I got are below:

Router statistics master socket


Router statistics extension


I noticed the noise margin was slightly higher on the master socket but the downstream connection speed was still ~1Mb.

I've raised a ticket with SKY and answered the various questions on the response email but would appreciate anyone's opinions on this here.

Is it possible that the ongoing fault on the BT line (this may of been ongoing for months as there was always a small amount of noise on the line) has caused the ADSL to drop back to a lower speed?

Thanks
Martin

[Smithy99]

You extension is causing noise on the line, this is why the stats are better when directly into the Test socket.

It looks like your line is capped, you should run the router from the master socket with a filtered faceplate and then connect to the PC via ethernet or homeplugs for the best connection.

Once you have done this, ring Sky and get them to uncap the line and also see if the line works better on the G.DMT profile (assuming you are now on ADSL2)

Also, do you have any other phone sockets, if you do, ensure that they also have ADSL filters fitted to them as the very FIRST thing plugged in to them.

When you remove the faceplate from the master socket, are all the other extensions dead?

[MartinL]

Hi Smithy,

Thanks for the reply, I thought the noise margin decrease on the test socket maybe due to noise caused by the noise on the extension socket but wasn't sure if this was a significant increase over the test socket levels.

I did think it was something other than just SNR that was causing the speed issue as changing from the extension socket to the test socket made little difference to the connection speed (assuming the BT line is o.k now of course).

I'm not sure if I have ADSL or ADSL2, is there a method of checking other than calling Sky?

I do have other phone sockets and the first thing connected to them is a microfilter before any other devices. The only exception to this is the Sky+ box modem connection. The Sky Broadband router is connected to an extension twin faceplate in the lounge with one socket having a microfilter plugged into it along which then connects to the house phone and the ADSL modem in the ADSL socket on the microfilter. The other socket on the twin faceplate is connected to the Sky+ box without a microfilter.
For some reason I never put a microfilter on the Sky+ box modem, should it have one?

When I remove the faceplate from the master socket one extension cable is still connected to the line as a BT Engineer connected the extension into the back of the master socket. I guess this could be causing some extra noise, but I was getting 2-3Mb downstream previously with the same set-up.

I'll see what Sky replies with and request if the line is capped (I have Broadband Max unlimited) and if I am on ADSL or ADSL2.

Thanks
Martin

[Smithy99]

Ok, now were getting somewhere.

1st, the Sky receiver phone socket. This should have the filter in FIRST, then the twin splitter goes into the phone side and out from there, this will cause a noise problem and needs to be addressed.

2nd, You need to remove that extension from the master socket terminals and connect it to terminals 2 & 5 on the faceplate, this again will cause noise on the line.

Once you do this, you may get a nice surprise.

It is pointless ringing Sky until you have sorted out your wiring issues, these will be at the heart of your problems.

[MartinL]

Hi Smithy99,

Thanks for the advice:

1st, the Sky receiver phone socket. This should have the filter in FIRST, then the twin splitter goes into the phone side and out from there, this will cause a noise problem and needs to be addressed.

I'm not sure if I was too clear on the connections. I have an extension socket in my lounge run from the master socket. The lounge end is terminated on a wall mounted twin socket. Connected to the twin socket I had:

1. The Sky+ receiver
2. The ADSL microfilter
2.1 House phone (in phone socket on microfilter)
2.2 Sky Broadband router

Yesterday afternoon I put a microfilter before the Sky+ receiver.

2nd, You need to remove that extension from the master socket terminals and connect it to terminals 2 & 5 on the faceplate, this again will cause noise on the line.

I'm reluctant to move this as it's technically on the BT side of the master socket and as far as I know your not supposed to touch this.

Yesterday at around 17:00 I noticed by Broadband disconnected and reconnected. I then got an email from Sky support telling me they had checked the connection and manually fixed it to 5.2Mb.

The router stats now show 5.2Mb downstream.



Im guessing that if I can improve the noise margin by checking the extensions e.t.c I maybe able to improve this further. 5.2Mb however is a lot better than the 1Mb I was getting.

Thanks again for advice.

Regards
Martin

[IWasNotTheEnemy]

If you have a test socket the faceplate is YOUR responsibility so you can remove what you like...

[Smithy99]

Just remove them from the a&b terminals, the're not meant to be there anyway and nobody will be bothered and it could make a world of difference.