Newbie - Connection suddenly very slow

Hi,
I am sure that this is something that a lot of people suffer from but I was hoping for some specific feedback on my situation.
We have had BT Broadband for about 3 months. It was running fine for the distance we are and what we expected - about 1.6Mb download speed.
It has recently slowed down DRAMATICALLY. We are now getting 0.1Mb download speed and 0.4Mb upload.
Stats from Bt router are:
ADSL Line Status
Downstream 608Kbps
Upstream 448Kbps

ADSL SEttings
VPI/VCI 0/38
Type PPPoA
Modulation ITU-T G.992.1
Latency Type Interleaved
Noise Margin (Down/Up) 16.9dB/14.0dB
Line Attenuation (Down/Up) 63.0dB/31.5dB
Output Power (Down/Up) 15.5dBm/12.3dBm

If anyone has any ideas about what might have happened and the best thing to do now is I would be most grateful.

I really cannot believe that 0.1Mbps is broadband.

Thanks.
Neil

When was the last time you turned the router off and on?

Turned it off for 3 hours Yesterday lunchtime - made no difference

Well there are two related things slowing you down at the moment.

The one you can see from the stats is the high downstream noise margin of 16.4dB. The implication of that, as you restarted it yesterday, is that you have had a bout of noise or lots of disconnections in an hour a bit ago, when the slow speeds started.

I think you would find that immediately after a reconnection it was about 15dB. The normal value is 6dB, and each 3dB step costs 500-750kbps.

For a fuller explanation first see the Noise Margin page on my website. Also have a read of the BT IP Profile page, as your IP Profile is the second factor in the slow speed.

Once you get the concepts, go to the Troubleshooting section where there is a page about high noise margin.

That tells you about the 10-14 day period for the system to lower the figure by 3dB, which then needs repeating. However, since I wrote that a system has been introduced whereby the ISP can request an SNR reset, which sets everything back to the defaults and starts a new 10-day training.

So if you are satisfied that the line is stable, though slow, you could ask for that to be done. The trouble is if the line is still unstable then you could make things worse as the reset would clear a thing called the FTR, which is a useful bit of evidence if it is currently at a higher figure than you are connecting. See the 10-day training page.

What might be a good idea would be to download RouterStats Lite, (scroll down past the full version), and monitor the noise margin for a few days to see how much it varies.

If you leave the Hub on at night then you need to leave the computer on running this as well.

Just another thought - you haven't recently got or replaced a Sky box have you?

Edited by RobertoS (Tue 24-Aug-10 16:20:40)

Thanks for this very detailed reply RobertoS.

I will have a look at the pages you suggest.

The line has always seemed stable if by that you mean no dropouts and reconnects - we don't ever seem to have had any but the telephone has been a bit dodgy at times - noisy and dropped calls.

We did have a sky box upgraded to sky+ a couple of months ago

Thanks again.
Neil

If it was OK for a while after the Sky box upgrade that probably wasn't the trouble. If things started going wrong at the same time then whoops!

Noisy phone and dropped calls is very suspicious. Could be a line fault between you and the exchange.

If you can try a Quiet Line test (17070 option 2), if that is noisy we are onto something.

If it is noisy the best thing to try next is a (preferably corded) phone direct into the test socket of the master socket. On the wall at the back in this pic.

Not sure when speed dropped exactly as only kids use this connection - I use a business line connection on BT Business.

Quiet test using current cordless is noisy but if I get a chance this evening I will try corded in test socket. One question - as I only switched modem off and on yesterday should i wait a few days to see if it picks up before disconnecting it again or do you not think thats neccessary?

Once again thanks.

In the next few days nothing is going to improve by staying connected, so disconnecting to try a corded phone in the test socket is fine.

The trouble is a connection when the sun is setting or later will be slower than a daytime one.

So if you haven't already done the test I would leave it till the morning or early evening tomorrow.

If you have done it, and now have an even lower sync, damn! Re-sync again after dawn to get a higher sync, but it will take days fro the IP Profile to rise again. Assuming the difference in the two connection speeds warrants different IP Profiles.