Help! Why has my connection gone from hero to zero?

Rik · Sep 21, 2009, 16:04:49

It's possible, but my gut feeling is that your line is carrying RF, which BT can fit a filter to remove. The problem with the phone is more puzzling. Normally, I'd suggest changing the filter, but you've effectively done that. Changing the phone would make sense as the next step, followed by a quite line test - dial 17070 and select option 2. If you hear crackling, then report it was a voice fault without mentioning ADSL.

emvisi · Sep 21, 2009, 16:38:28

Hi Rik

I've tried a variety of phones (including none at all this weekend!) and filters over the past couple of weeks and not achieved a stable connection. The line's not obviously noisy when I do a quiet line test: a bit of hiss with one phone, not evident on another, newer one (probably thanks to a better audio circuit). I mentioned your RF theory to Brian on Friday, and he logged a fault with BT. Haven't heard anything back yet.

This afternoon my sync dropped to an even less impressive 1150 Kbps and the noise margin has increased to between 28 and 30dB. Throughput is about 730 Kbps so I assume my profile is now 750 Kbps. Attenuation on the downstream line is fairly constant, at 41dB, but upstream attenuation has jumped up to 50dB, although it's still at 6dB NM and syncing at 976 Kbps, with a measured throughput of around 830 Kbps. Hey -- that's almost SDSL

Of course, I'm also now subject to the vagaries of WBC...

Rik · Sep 21, 2009, 16:43:22

That line sounds faulty.

emvisi · Sep 21, 2009, 17:09:05

BT round tomorrow, apparently

Rik · Sep 21, 2009, 17:10:55

Get the bacon butties ready.

emvisi · Sep 21, 2009, 17:33:11

Afternoon appointment, so I'm thinking Tunnock's Teacakes might be in order

Rik · Sep 21, 2009, 17:42:42

That should work as well.

emvisi · Sep 22, 2009, 15:16:03

Very nice chap from BT just came over and ran some tests. Apparently the line between my house and the DSLAM is clear as a bell, and there's no noise being injected at this end. Given the very high noise margins and low sync speed he's sure there's a problem at the exchange and is going off there to check things over and probably to 'lift and shift' me onto a different port.

Rik · Sep 22, 2009, 15:17:13

A port change could work wonders for you.

emvisi · Sep 22, 2009, 15:21:56

Cockburn's Special Reserve would be nice

Rik · Sep 22, 2009, 15:27:03

For once it wasn't me that got food and drink into a tech thread.

emvisi · Sep 22, 2009, 15:52:17

Sebby · Sep 22, 2009, 19:29:00

There's a first for everything!

emvisi · Sep 23, 2009, 10:35:27

Still waiting for something to happen...

Rik · Sep 23, 2009, 10:56:22

Quite possibly he exceeded his two hour slot, and has had to re-book the job. Support should be able to find out for you.

emvisi · Sep 23, 2009, 11:45:27

Apparently BT interpreted the tech's report as 'no fault found'

Support are on the case again...

Rik · Sep 23, 2009, 14:50:52

That's not the first time we've heard an engineer tell the customer he's off to do work at the exchange, then put in a cleared or no fault report.

emvisi · Sep 23, 2009, 15:42:16

Well something appears to happened...

Modem dropped the connection just before 3pm and eventually resynced at 4669 down (from 1150) / 445 up (from 800 odd). Downstream sync speed has obviously improved a bit, but upstream has halved.

Noise margins are now:

Down: 15dB (from 30)
Up: 21dB (from 6)

So it appears the upstream connection has been crippled in order to improve the downstream speed. Not what I'd call a fix. Remains to be seen what sort of download throughput I might achieve, as my profile is still rubbish. Quick speed test reports 730 down / 360 up. What a crock

Rik · Sep 23, 2009, 15:53:37

There is often a trade-off between upstream and downstream frequencies, but the change in the noise margins suggest that there's been a significant change to the physical characteristics of your line. Have you asked support what's been done?

emvisi · Sep 23, 2009, 16:01:59

I asked for an update, but will call again if I don't hear something soon.

This isn't very encouraging:

Download speed achieved during the test was - 703 Kbps
For your connection, the acceptable range of speeds is 200-1000 Kbps.
Additional Information:
Your DSL Connection Rate :4668 Kbps(DOWN-STREAM), 445 Kbps(UP-STREAM)
IP Profile for your line is - 750 Kbps

I'm now on a 1M connection?!

Rik · Sep 23, 2009, 16:03:24

You need to wait for the profile to update, it should only take a day or so. IDNet will be waiting for the engineer's report to be fed back to them.

emvisi · Sep 23, 2009, 16:30:24

I'm sure you're right, Rik. However, I'm also sure that the BT Speedtester has always previously stated the upper limit of my connection to be 7160 Kbps (or thereabouts), even when the IP profile dropped through the floor.

Rik · Sep 23, 2009, 16:31:45

The BT tester didn't use to give the upper or lower limits. Given it's been broken for several days, it wouldn't surprise me if they've changed it yet again.

Rik · Sep 23, 2009, 16:45:33

I've actually managed a test now.

Download speedachieved during the test was - 3649 Kbps
For your connection, the acceptable range of speeds is 600-7150 Kbps.
Additional Information:
Your DSL Connection Rate :4816 Kbps(DOWN-STREAM), 760 Kbps(UP-STREAM)
IP Profile for your line is - 4000 Kbps

emvisi · Sep 23, 2009, 17:12:34

I should have said 'whenever I've seen it'. And it showed the same as yours: 600 to 7150.