Noise Margin / errors help

[richbeales]

Hi, I'm currently on sky broadband Mid, and have been capped at 1.5Meg since May. I'm currently trying to figure out how to fix this and why it's happening. Sky say it's capped there due to a large number of errors on the line. I'm running out of ideas as to why, here's what i've got:

1) I've got a single NTE style master socket. My results are the same whether using the test socket or not.
2) Netgear v1 white ADSL router plugged in through an ADSLnation high-quality filter, with a single downstairs telephone
3) One extension upstairs with no phone plugged in (I've now plugged in a filter to this socket anyway just to be sure - is this necessary?)
4) BT iPlate fitted to master socket

Here's what I've tried:

I've looked at the BT junction box inside the front door, which although slightly corroded doesn't look too bad. I've got what looks like Cat5 running between this junction box and the master socket (~3 metres). I've tried a quiet line test (17070 option 4) and it comes back and says "some echo and very little noise, you may have a problem with your line". This result is the same in test socket and plugged in normally.

The problem I've got is obviously the cap, and the errors. I've also noticed that my Noise Margin as reported in the stats can go from 0.3dB to 25dB, normally 7-10dB, but I'm not sure it should be jumping around like that. It's quite windy outside today (?) Line attenuation is 51-52dB so should be able to get ~4-4.5MBps if the noise margin wasn't so crazy.

I've tried wiggling / replacing various cables and connections (and unplugging telephone) to try to get this noise margin to change at will, but it seems to be random.

Where should I go from here?

Thanks, Rich.

[simonmpoulton]

If the noise margin is fluctuating that much then there is something seriously wrong with your line and you should get BT out to fix it provided that this occurs also in the test socket.
If you have the extension upstairs connected to an ADSLNation or similar ADSL faceplate on your master socket then no you dont need a filter on it.

[RUNITDIRECT]

1) I've got a single NTE style master socket. My results are the same whether using the test socket or not.
2) Netgear v1 white ADSL router plugged in through an ADSLnation high-quality filter, with a single downstairs telephone
3) One extension upstairs with no phone plugged in (I've now plugged in a filter to this socket anyway just to be sure - is this necessary?)
4) BT iPlate fitted to master socket

Sounds like you have issues with the line which will need BT/OR to sort out but I'd replace the iPlate/existing plug in filter with an Openreach ADSL faceplate. That way the extension wiring is isolated away from the ADSL signal. The iPlate will filter the bell wire on this extension but you still have the ADSL pair running where you do not need it which it could pick up noise.

[Isitme]

One extension upstairs with no phone plugged in (I've now plugged in a filter to this socket anyway just to be sure - is this necessary?)

Is this extension connected to the faceplate of the NTE5 or plugged into its face?

[richbeales]

Looks like 4 wires go upstairs from inside the Master socket.

[Isitme]

Looks like 4 wires go upstairs from inside the Master socket.

In that case they are probably incorrectly connected. Remove the backplate of the NTE5 and see if they are connected to the A-B terminals. These are the main terminals and only the incoming line should be connected to them. If they are connected there it probably accounts for some of the prblems you are having.

[richbeales]

I'm still getting loads of errors in the detailed stats:

Previous 1 day time = 24 hours 0 sec
SF = 5330628
CRC = 3856
LOS = 22
LOF = 17
ES = 167

I've taken the back off the master socket, and the "blue" pair seem correctly installed to the A-B terminals, with the four wires going upstairs from the "front" part of the faceplate.

I've done several quiet line checks and all say "very little noise" but "some echo", I don't want to get charged by BT for a visit, but I don't think there's much more I can do internally. How do I go about getting this sorted/looked at? Do I have to get Sky to get BT out? What do I need to do to convince sky?

Downstream SNR is currently 9.4dB, but at current sync speed I think it should be >20.

Mode: ADSL2+
Channel: Fast
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 9.4 15.9
Attn(dB): 51.5 32.4
Pwr(dBm): 16.8 12.4
Max(Kbps): 5012 941
Rate (Kbps): 1530 604

Thanks all.

[simonmpoulton]

If your receiving these problems from the test socket then the ONLY thing it can be is a line fault on BT's side and you wont get charged for them to sort it out. Remember the test socket is where BT becomes responsible for faults. You can get SKY to book a call with BT to sort it or you can phone BT directly to sort it out.

[RUNITDIRECT]

As Simon says if this is present in the test socket then you have done all you can, it's down to BT/OPenreach to sort out.

[Smithy99]

It would be worth removing the faceplates and taking a couple of pictrues to post here and also the junction box.

As stated, chances are the line is at fault but it will do no harm in letting us see the wiring etc.