Broadband slowed to a crawl

[#1]

John, I think this is what you need to understand to see why HP and Oldjim are telling you that you've found your fault:
There are two things affecting download speed in your case.
1. The modem sync speed - that's the downstream kbps rate, 5632 kbps in your last post, is how fast the modem can talk to the exchange.
2. There's also something called the IP Profile, which is a kind of speed limit BT put on your line. It is supposed to be just slightly lower than your sync speed and it prevents websites etc sending you data faster than your line can deliver it. If data is sent too fast then it doesn't back up in a traffic jam trying to get down your line, it just gets thrown away, and this would make the connection seem very unreliable.
The problem is this. When your modem syncs at a lower speed than your IP Profile, the IP Profile will almost immediately adjust so that it is once more below your modem sync speed. But when your modem resync higher than your IP Profile, it can take up to five days before the BT systems adjust your IP Profile to match. You can never download data faster than your IP Profile, even if your modem sync speed is way faster.
So basically, you had a fault in your wiring and your modem sync speed crashed down to 160 kbps. The IP Profile was immediately set by BT to 135 kbps.
You then fixed the wiring problem and your modem sync speed jumped back up to 5632 kbps. But your download speed is still limited to 135 kbps because your IP Profile has not yet been updated. You'll just have to wait a few days for that to happen.
When sorting out line problems, always look to the modem sync speed, not the download speed, to see what affect the changes you have just made have had.
As for the 63 dB downstream attenuation, I think you can ignore that - the modem is obviously mis-reporting.
Ian

[#2]

Thanks everyone.  I'll wait a few days and hope it comes back up to speed. 
Next problem will be persuading my wife (who hates computers) that if she wants to avoid loose extension leads trailing through the house, I really do need to lift the fitted carpets and the floorboards in both the sitting room and the dining room to lay some new phone cable ...... and if I have to run a new phone cable, I might as well run a Cat 5e network cable alongside it.
John

[#3]

Download throughput last night was only 89 Kbps. 
Just done a BT Speed test at 12:30 today
DSL connection rate 5216 Kbps downstream,  448 Kbps upstream
IP Profile for line is 4500 Kbps
Actual IP throughput achieved during the test was 4110 Kbps   
'My broadband speed' tester gives 4236 Kbps download and 383 Kbps upload. 
Modem is still showing downstream attenuation of 63dB so is clearly reporting a false figure.  Modem also seems to have dropped the internet connection a couple of times during the night, not sure why, but it's not a major problem to reconnect.
Thanks for you help everyone.
John

[#4]

Quote from: watton

Thanks everyone.  I'll wait a few days and hope it comes back up to speed.  Next problem will be persuading my wife (who hates computers) that if she wants to avoid loose extension leads trailing through the house, I really do need to lift the fitted carpets and the floorboards in both the sitting room and the dining room to lay some new phone cable ...... and if I have to run a new phone cable, I might as well run a Cat 5e network cable alongside it. John

When you lay some new tel extension wiring, make sure you don't connect the Ring (ringer) wire.  Most modern telephones don't need it.  Could have been the cause of your problems with your old wiring.
Might be worth updating your Router firmware if it has such flaky stats.  May even improve your line drops.

[#5]

Just a quick update. 
Stats have been steadily improving.  Latest BT speed test at 12:53 today gives:
DSL connection rate 6272Kbps downstream,  448Kbps upstream
IP Profile for line 4500Kbps
Actual IP throughput achieved was 4198Kbps
I have updated the modem firmware and it now reports:
Actual data rate: 6272Kbps downstream, 448Kbps upstream
Noise Margin:  25dB upstream,  12dB downstream
Attenuation:  11dB upstream 23dB downstream
Also discovered the dropped connections were due to an incorrect modem setting and since I have reset it to "Always on" there have been no more disconnections.
Everything looks much better.  With these stats, is there any chance that BT might increase the profile for the line?  (...or am I getting greedy?)
John

[#6]

Quote from: watton

With these stats, is there any chance that BT might increase the profile for the line?

Probably, but it's all automated and takes time (days).

[#7]

probally get a profile of 5500kbps if your router stays sync'ed at that speed.

[#8]

Spot on Asbo Dog!
Carried out another BT speed test tonight at 23:08
DSL Connection rate 6272 Kbps downstream, 448 Kbps upstream
IP profile for your line is 5500 Kbps 
Actual IP throughput achieved during the test was 5011 Kbps 
Best speed I've had for many months. That's what I call broadband!
I still need to rewire the house properly, but at these speeds I'm tempted to leave the temporary telephone extension lead in place.
Once again, thanks to everyone on the forum who helped me sort my speed problems out.  I've learned a lot and it's great to be part of a community of helpful people who are so willing to share their knowledge.  I've been dabbling with computers since my first Sinclair ZX81and I still learn something new every day.
John

[#9]

Still doing tests and the speed now seems to be going up and down like a yoyo.
All tests since 5 November are showing DSL connection 6272 downstream, 448 upstream, with IP profile for line 5500
At 23:08 on 5 November actual IP throughput was 5011 Kbps   
At 19:44 on 6 November actual IP throughput was   781 Kbps   
At 11:19 on 7 November actual IP throughput was 5096 Kbps   
At 18:25 on 9 November actual IP throughput was   672 Kbps   
I expect some drop in speed during the early evening peak time, but this is stupid.  Surely contention ratios at the exchange can't account for such a wide fluctuation?  BT exchange is showing green.
I have three days left in my account period and have not even used half of my monthly allowance yet.
John

[#10]

are the speed results from the bt tester or another speed tester site?

[#11]

From the BT speed tester.  Have also tried the PN one which is reporting marginally higher download speeds -  just over 1Kbps

[#12]

Back to normal speed this morning.
10 November 2008 10:48
Test1 comprises of Best Effort Test: -provides background information.
    Your DSL connection rate: 6272 kbps(DOWN-STREAM),  448 kbps(UP-STREAM)
    IP profile for your line is - 5500 kbps
    Actual IP throughput achieved during the test was - 4956 kbps

[#13]

do a few more tonight bettween 6pm and 8pm and see if the speed drops again.
what package are you on ?

[#14]

I was out tonight, but did a test before I left and another one when I got home.
10/11/08 19:03
Test1 comprises of Best Effort Test:  -provides background information.
    Your DSL connection rate: 6272 kbps(DOWN-STREAM),  448 kbps(UP-STREAM)
    IP profile for your line is - 5500 kbps
    Actual IP throughput achieved during the test was - 740 kbps
10/11/08 23:13
Test1 comprises of Best Effort Test:  -provides background information.
    Your DSL connection rate: 6272 kbps(DOWN-STREAM),  448 kbps(UP-STREAM)
    IP profile for your line is - 5500 kbps
    Actual IP throughput achieved during the test was - 4859 kbps
10/11/08  23:50
PN's "My Broadband Speed" tester reported 5315Kbps downstream, 382 upstream
Speedtest.net reported 5319Kbps downstream, 378Kbps upstream
Plusnet have my line speed set at 5500Kbps to match BT
My local telephone exchange (LWNWOO) VP capacity is showing green (last update 20 October) and has been green for several weeks.
Modem/router is curently reporting Noise Margin:  25dB upstream  12dB downstream;  Attenuation  11dB upstream  23dB downstream and has reported similar figures for the last 10 days
My setup hasn't changed since I bypassed my home telephone extension wiring (I'm still using a temporary extension lead), except that I am now using a wired ethernet connection to the router instead of wireless.
I'm still on the old "Broadband Plus"  £14.99 per month package 'up to' 8Mb with a 4GB monthly peak usage allowance (of which I have used less than 1GB).  It claims to offer average speeds of 5-6Mb and states "it is likely that speeds no greater than 2Mb will be achieved at peak usage times".  Broadband Plus seems to meet all my current needs, but I have been wondering whether I should switch to the new Option 2 at the same price.
John

[#15]

i only joined PN when they where offering the new products so dont know a great deal about the old products.
But from what ive seen on the forum in the past diffrent levels of reistrictions are applied to the old products where on broadband your way it just gets capped at 128k when you have hit your usage limit and this speed cap is day and night.
is it that you have hit your peak limit  didnt see that you said you only used 1gb peak.
But still seems the speed test  surrgest its a peak time cap.
Maybe PN staff can look at your account and see if any caps are in place for the 6pm-8pm ish time.