Speed deteriorated

bridgej · Feb 19, 2010, 12:43:31

I had a nice steady 4000Kbps IP profile and a noise margin around 6db for my line until about a month a go. The noise margin fell to 0.1db and my connection was slower than dial up.

Since then, my IP profile has dropped to 3000k, and has never recovered and the noise margin is now always around the 12db mark.

I am using a 2wire 2700 HGV router and the current stats are:

DSL Line (Wire Pair):    Line 1 (inner pair)
Protocol:    G.DMT2 Annex A
Downstream Rate:    3881 kbps
Upstream Rate:    883 kbps
Channel:    Interleaved
Current Noise Margin:    12.2 dB (Downstream) 6.3 dB (Upstream)
Current Attenuation:    48.5 dB (Downstream) 29.2 dB (Upstream)
Current Output Power:    18.8 dBm (Downstream) 12.6 dBm (Upstream)

Last time I had a problem, IDNet tweaked something and the speed cam back up within days, but this time they dont seem so bothered about it and haven't ofered any advice or help and said the noise margin doesn't really affect the speed (I thought it did and the lower the better).

Is there anything that can be done? I have the router connected to the master socket and I am about 1.8 miles from the exchange and nothing within this house has been changed to cause the drop in speed which in effect is a 25% reduction.

Any ideas?

Rik · Feb 19, 2010, 12:55:40

Ask whether you've been put on a banded profile.

kinmel · Feb 19, 2010, 16:56:29

Quote from: bridgej on Feb 19, 2010, 12:43:31
but this time they dont seem so bothered about it and haven't ofered any advice or help and said the noise margin doesn't really affect the speed (I thought it did and the lower the better).

If you are not connected at the full 8meg, then that is nonsense. As the SNR increases, the Sync Rate decreases and that Sync Rate determines the Profile, which in turn limits throughput. BT's equipment has probably put you on a minimum noise margin of 12dB due to line errors and your Sync rate will not greatly alter from the present reading. At 6dB you would connect at 5058

Quote
Is there anything that can be done? I have the router connected to the master socket and I am about 1.8 miles from the exchange and nothing within this house has been changed to cause the drop in speed which in effect is a 25% reduction.

Any ideas?

Have you read through our troubleshooting FAQ ?

bridgej · Feb 20, 2010, 09:13:07

Quote from: kinmel on Feb 19, 2010, 16:56:29
If you are not connected at the full 8meg, then that is nonsense. As the SNR increases, the Sync Rate decreases and that Sync Rate determines the Profile, which in turn limits throughput. BT's equipment has probably put you on a minimum noise margin of 12dB due to line errors and your Sync rate will not greatly alter from the present reading. At 6dB you would connect at 5058

And when I had a noise margin of about 6db, 5000 was around the mark I was connecting at

Glenn · Feb 20, 2010, 09:15:37

Are you getting many errors reported by your router?

bridgej · Feb 20, 2010, 09:18:55

Dont know what all this means, but here they are:

Transmit and Receive Data
IP    Bytes       Packets       Errors
Transmit:    764267       4258       0
Receive:    4372039       5097       0

Help
Data Errors
Statistics
Collected for 0:10:09
   Since Reset   Current 24-Hour Interval   Current 15-Minute Interval   Time Since Last Event
ATM Cell Header Errors:   0   0   0   0:00:00
ATM Loss of Cell Delineation:   0   0   0   0:00:00
DSL Link Retrains:   0   0   0   0:00:00
DSL Training Errors:   1   1   1   0:09:32
DSL Training Timeouts:   0   0   0   0:00:00
DSL Loss of Framing Failures:   0   0   0   0:00:00
DSL Loss of Signal Failures:   0   0   0   0:00:00
DSL Loss of Power Failures:   0   0   0   0:00:00
DSL Loss of Margin Failures:   0   0   0   0:00:00
DSL Cumulative Errored Seconds:   0   0   0   0:00:00
DSL Severely Errored Seconds:   0   0   0   0:00:00
DSL Corrected Blocks:   10   10   10   0:04:19
DSL Uncorrected Blocks:   0   0   0   0:00:00
ISP Connection Establishment:   1   1   1   0:01:05

Glenn · Feb 20, 2010, 09:31:21

Have another look tonight or tomorrow morning it's only collected data for the last few minutes since it was rebooted/switched on.

bridgej · Feb 21, 2010, 10:45:08

Not sure why my posts from yesterday have been removed from this subject, but here it is again with router stats after 16 hours of operation, any ideas as to why my connection is now 25% slower after a fantastic 4 months on the higher IP profile??:

I had a nice steady 4000Kbps IP profile and a noise margin around 6db for my line until about a month a go. The noise margin fell to 0.1db and my connection was slower than dial up.

Since then, my IP profile has dropped to 3000k, and has never recovered and the noise margin is now always around the 12db mark.

I am using a 2wire 2700 HGV router and the current stats are:

DSL Line (Wire Pair): Line 1 (inner pair)
Protocol: G.DMT2 Annex A
Downstream Rate: 3881 kbps
Upstream Rate: 883 kbps
Channel: Interleaved
Current Noise Margin: 12.2 dB (Downstream) 6.3 dB (Upstream)
Current Attenuation: 48.5 dB (Downstream) 29.2 dB (Upstream)
Current Output Power: 18.8 dBm (Downstream) 12.6 dBm (Upstream)

Last time I had a problem, IDNet tweaked something and the speed cam back up within days, but this time they dont seem so bothered about it and haven't ofered any advice or help and said the noise margin doesn't really affect the speed (I thought it did and the lower the better).

Is there anything that can be done? I have the router connected to the master socket and I am about 1.8 miles from the exchange and nothing within this house has been changed to cause the drop in speed which in effect is a 25% reduction.

Any ideas?

IP    Bytes        Packets        Errors
Transmit:    14083685       82779       0
Receive:    75077518       94111       0

Help
Data Errors
Statistics
Collected for 16:42:44
   Since Reset   Current 24-Hour Interval   Current 15-Minute Interval   Time Since Last Event
ATM Cell Header Errors:   10   10   0   0:40:09
ATM Loss of Cell Delineation:   3   3   0   0:40:09
DSL Link Retrains:   0   0   0   0:00:00
DSL Training Errors:   1   1   0   16:42:07
DSL Training Timeouts:   0   0   0   0:00:00
DSL Loss of Framing Failures:   0   0   0   0:00:00
DSL Loss of Signal Failures:   0   0   0   0:00:00
DSL Loss of Power Failures:   0   0   0   0:00:00
DSL Loss of Margin Failures:   0   0   0   0:00:00
DSL Cumulative Errored Seconds:   8   8   0   0:40:09
DSL Severely Errored Seconds:   0   0   0   0:00:00
DSL Corrected Blocks:   4513   4513   10   0:01:14
DSL Uncorrected Blocks:   11   11   0   0:40:09
ISP Connection Establishment:   1   1   1   0:01:06

Any help appreciated.

Rik · Feb 21, 2010, 10:48:28

You have your own thread now...

http://www.idnetters.co.uk/forums/index.php?topic=18869.msg451824#msg451824

bridgej · Feb 21, 2010, 10:49:38

ok cheers

Rik · Feb 21, 2010, 10:50:38

Your line has just dropped, so that suggests instability. DLM is trying to manage it by raising the target noise margin, hence the slower speed. Do you have and NTE5 master socket?

bridgej · Feb 21, 2010, 10:50:46

router stats after 18 hours:

Transmit and Receive Data
IP    Bytes       Packets       Errors
Transmit:    16581688       99820       0
Receive:    88802712       112479       0

Help
Data Errors
Statistics
Collected for 18:03:08
   Since Reset   Current 24-Hour Interval   Current 15-Minute Interval   Time Since Last Event
ATM Cell Header Errors:   19   19   1   0:01:52
ATM Loss of Cell Delineation:   4   4   0   0:47:24
DSL Link Retrains:   0   0   0   0:00:00
DSL Training Errors:   1   1   0   18:02:31
DSL Training Timeouts:   0   0   0   0:00:00
DSL Loss of Framing Failures:   0   0   0   0:00:00
DSL Loss of Signal Failures:   0   0   0   0:00:00
DSL Loss of Power Failures:   0   0   0   0:00:00
DSL Loss of Margin Failures:   0   0   0   0:00:00
DSL Cumulative Errored Seconds:   15   15   1   0:01:52
DSL Severely Errored Seconds:   0   0   0   0:00:00
DSL Corrected Blocks:   4642   4642   3   0:01:00
DSL Uncorrected Blocks:   20   20   1   0:01:52
ISP Connection Establishment:   1   1   1   0:01:06

bridgej · Feb 21, 2010, 11:24:23

Quote from: Rik on Feb 21, 2010, 10:50:38
Your line has just dropped, so that suggests instability. DLM is trying to manage it by raising the target noise margin, hence the slower speed. Do you have and NTE5 master socket?

I think so, the router is connected to the socket inside, (I've removed the face plate)

Rik · Feb 21, 2010, 11:33:58

In that case, do you have a battery-powered AM radio? If so, de-tune it so that it's only producing white noise, then follow your phone line from where it enters the house to the router, listening for an increase in noise level. If you hear one, that's the source of the problem.

bridgej · Feb 21, 2010, 11:43:34

Ok thanks for that, just one question, why would the cable suddenly develop a fault as it's untouched

Rik · Feb 21, 2010, 11:47:26

Because... There's no simple answer to that question, unfortunately. Within the house, an electrical device may have become noisy, the cable to the router could have degraded etc. Externally, there's dozens of joints between you and the exchange, any of which may have become corroded, or the cable itself could have degraded, or there's more cross talk now as ADSL subscriptions increase. It's only really possible for BT to diagnose a cause outside your house, and they may not be willing to do so.