Are you connecting wired or wireless to the router? Local interference, particularly on wireless, can arise at any time as people in the neighbourhood get connected or change connection.

I don't think that your router is the problem. That number of errors isn't significant over the course of a day (ignore the FEC error count, they are errors automatically corrected by interleaving and do not harm your throughput).

Your line is under performing and would normally sync at the maximum 7616 kbps (as the line is interleaved) for your attenuation. You seem to suffer from noise and your target SNR margin seems to have been raised to 9 from the default 6dB. That would account for the less than perfect sync.

If you have a test socket within your master BT socket it would be useful to get the stats when the router is plugged in there.

Looks like you may well be right that there's not a problem with the router John, as when I came home today my connection speed seemed a bit more back to normal (I downloaded a test file from Zen at around 5Mb). It has dropped this evening but isn't significantly slower than what I'm used to.

As per the question RobertoS posed, my PC has a wired connection to the router.

Here's two lots of stats taken from today. The first with the router, phones etc plugged in as normal, the second is the router plugged into the test socket of the master socket.

16:49 11/05/2011
speedtest.net - 5.83 Mb/s

Uptime: - 1 day, 23:51:02
Bandwidth: - 448 / 7,200
Line Attenuation: - 17.0 / 28.0
SN Margin: - 21.0 / 9.0
CRC Errors: - 0 / 1,771
HEC Errors: - 0 / 1,675

19:50 11/05/2011
speedtest.net 4.36 Mb/s

Uptime: - 0 days, 2:53:49
Bandwidth: - 448 / 8,096
Line Attenuation: - 16.5 / 27.0
SN Margin]: - 29.0 / 14.0
CRC Errors: - 0 / 1
HEC Errors: - 0 / 1

To me that suggests you have a problem with your internal wiring. The stats should be the same in and out of the test socket. The likely culprit is a bell wire attached to terminal 3.

Ok cheers, what can I do about that though? It's not a fault that can be raised with BT, at least not one without significant cost is it? I spoke to someone from BT not that long ago about how much it would cost to get the internal wiring replaced and he said it'd be expensive and not really worth it. My connection was ok then though, I was happy enough with the 4-5Mb I've been getting since switching to Zen. But the 1-2Mb (which it has dropped to again now) is pretty dismal.

Most home phone wiring jobs are simple and DIY (quite legally, BT is required up to the master socket only).

Take a photo of the wiring of your master socket and you will get advice. Just post a link to the photo on a site such as imageshack.

Ok I'lll take a photo of the socket and post it this weekend.

However, I'm more concerned about why my previously fairly stable 4-5Mb connection has suddenly deteriorated? I thought it was perhaps just a blip when a couple of speedtest.net results showed 4Mb (actual downloads still slow though) but it just seems all over the place. Sometimes fine, other times a bit slow, and sometimes very slow. I should also add, I'm connected with a different router so that pretty much rules out it being the router as you previously stated (though I can't see how to get line stats from this router).

I've just ran two tests within the last hour, inbetween times the connection dropped:

5/13/2011 5:10 PM GMT 1.62 Mb/s 0.36 Mb/s 142 ms
5/13/2011 6:04 PM GMT 4.80 Mb/s 0.37 Mb/s 93 ms

I've just downloaded a test file from sourceforge, it downloaded at 5Mb+. I'm now downloading a test file from Zen, and it's a bit slower 3-4Mb. Still a lot faster than it was an hour ago?!?

Edited by mac_d (Fri 13-May-11 18:18:33)

In reply to a post by john2007:

Most home phone wiring jobs are simple and DIY (quite legally, BT is required up to the master socket only).

Take a photo of the wiring of your master socket and you will get advice. Just post a link to the photo on a site such as imageshack.

Not sure if these shots are good enough to see clearly what needs to be seen (been trying to wait for a bright day but not had any!):

http://imageshack.us/photo/my-images/193/socket1.jpg/
http://imageshack.us/photo/my-images/27/socket2.jpg/

Any chance of getting a top-down view of the terminal block on the detachable faceplate? I can't make out where those orange and blue striped wires are connected. Use flash?

Alternatively the terminals should be numbered and you could say which wire is attached where (seem to be white with orange stripes, orange with white stripes, white with blue stripes, blue with white stripes).

Looks ok, only got wires on 2&5. New style Openreach branded master so has the ring wire filtered already.