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Speed very low and erratic

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kjpetrie
Rising Star
Posts: 101
Thanks: 8
Fixes: 1
Registered: 19-12-2010

Speed very low and erratic

When I first had service at this address in February my speed was around 4 Mb/s. A few weeks ago it was around 3.5 Mb/s. Today it is only 0.5 Mb/s.
Here is the Link Info from router before I ran BT speed tests:

Physical Connectivity OK
DSL Connection
Link Information

Uptime: 4 days, 1:48:45
DSL Type: G.992.3 annex A
Maximum Bandwidth (Up/Down) [kbps/kbps]: 1,128 / 2,724
Bandwidth (Up/Down) [kbps/kbps]: 444 / 680
Data Transferred (Sent/Received) [MB/MB]: 31.70 / 465.08
Output Power (Up/Down) [dBm]: 12.5 / 16.0
Line Attenuation (Up/Down) [dB]: 30.0 / 47.5
SN Margin (Up/Down) [dB]: 27.0 / 21.5
Vendor ID (Local/Remote): TMMB / IFTN
Loss of Framing (Local/Remote): 988 / 0
Loss of Signal (Local/Remote): 3,014,611 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 9,764,744 / 0
FEC Errors (Up/Down): 0 / 1,033
CRC Errors (Up/Down): 30 / 40
HEC Errors (Up/Down): 5 / NA

And here is the not very useful result of the BT speed test after changing my log-in details as instructed:
Quote
 
FAQ
Results Image not loaded

Your speed test has completed and the results are shown above, however during the test an error occurred while trying to retrieve additional details regarding your service. As a result we are unable to determine if the speed you received during the test is acceptable for your service. Please re-run the test if you require this additional information.

And from the members' centre page:
Quote

Estimated line speed:
    There's no speed estimate currently held on your account.
Current line speed:
    0.5 Mb

After returning to my PN log-in details my Link Info now looks like this:
 	
DSL Connection
Link Information

Uptime: 0 days, 0:12:02
DSL Type: G.992.3 annex A
Maximum Bandwidth (Up/Down) [kbps/kbps]: 1,068 / 4,744
Bandwidth (Up/Down) [kbps/kbps]: 444 / 4,408
Data Transferred (Sent/Received) [MB/MB]: 1.46 / 3.67
Output Power (Up/Down) [dBm]: 12.5 / 18.5
Line Attenuation (Up/Down) [dB]: 30.0 / 48.5
SN Margin (Up/Down) [dB]: 23.0 / 6.0
Vendor ID (Local/Remote): TMMB / IFTN
Loss of Framing (Local/Remote): 988 / 0
Loss of Signal (Local/Remote): 3,014,611 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 9,764,744 / 0
FEC Errors (Up/Down): 0 / 600
CRC Errors (Up/Down): 22 / 0
HEC Errors (Up/Down): 0 / 0

However, my speed is still down at 0.5 Mb/s.
What's going on?
16 REPLIES
Plusnet Help Team
Plusnet Help Team
Posts: 17,567
Thanks: 597
Fixes: 151
Registered: 05-04-2007

Re: Speed very low and erratic

Quote
Bandwidth (Up/Down) [kbps/kbps]: 444 / 680

This is why your profile went down to 500. Something has caused the line to connect at a much lower rate than normal.
Quote
Bandwidth (Up/Down) [kbps/kbps]: 444 / 4,408

Since then the line has reconnected back at over 4Mb, so I'll adjust the profile on our side to match this. Give it 5 minutes, if you don't see an improvement in your speeds then log in to the router and disconnect/reconnect once.
If this post resolved your issue please click the 'This fixed my problem' button
 Chris Parr
 Plusnet Help Team
kjpetrie
Rising Star
Posts: 101
Thanks: 8
Fixes: 1
Registered: 19-12-2010

Re: Speed very low and erratic

Thanks, that's done it.
I wonder whether that something could have been the rain. I seem to see a pattern of reduced speeds when it rains, although this was a bigger reduction than I've seen before.
Plusnet Help Team
Plusnet Help Team
Posts: 17,567
Thanks: 597
Fixes: 151
Registered: 05-04-2007

Re: Speed very low and erratic

It's possible if there is a bad joint that is allowing water into it somewhere along the line. Keep an eye on the performance and the weather and let us know it goes.
If this post resolved your issue please click the 'This fixed my problem' button
 Chris Parr
 Plusnet Help Team
kjpetrie
Rising Star
Posts: 101
Thanks: 8
Fixes: 1
Registered: 19-12-2010

Re: Speed very low and erratic

After 2 and a half years, the problem has just recurred. Once again the speed test claims 0.4 Mb/s is acceptable for my line and the maximum download is 0.5Mb/s, despite the fact speeds have typically been 3-4Mb/s until now. Can't blame rain this time; we haven't had any for a couple of weeks.

The test does seem to have a curious definition of acceptable performance. It seems to assume that whatever is currently achievable is acceptable. So, if line quality deteriorates, the lower quality automatically becomes "acceptable" for the now lower-quality line. What is defines what ought to be, even when it changes unexpectedly.

	Link Information
			
Uptime:	1 day, 21:30:28
DSL Type:	G.992.3 annex A
Maximum Bandwidth (Up/Down) [kbps/kbps]:	1,324 / 3,360
Bandwidth (Up/Down) [kbps/kbps]:	444 / 472
Data Transferred (Sent/Received) [MB/MB]:	30.04 / 265.47
Output Power (Up/Down) [dBm]:	12.5 / 15.5
Line Attenuation (Up/Down) [dB]:	30.5 / 49.5
SN Margin (Up/Down) [dB]:	31.0 / 22.5
Vendor ID (Local/Remote):	TMMB / IFTN
Loss of Framing (Local/Remote):	91 / 0
Loss of Signal (Local/Remote):	983,028 / 0
Loss of Power (Local/Remote):	0 / 0
Loss of Link (Remote):	0
Error Seconds (Local/Remote):	2,031,597 / 0
FEC Errors (Up/Down):	0 / 3,739
CRC Errors (Up/Down):	144 / 656
HEC Errors (Up/Down):	176 / NA
jab1
Seasoned Pro
Posts: 1,335
Thanks: 219
Fixes: 5
Registered: 24-02-2012

Re: Speed very low and erratic

I don't claim to be an expert, but looking at those stats, I would say you have problems with connection - your LOS (local) and ES (local) both stand out as very high, and it looks like DLM has hiked your SNR to try and stabalise, thus knocking your speed for six.

I would run through the 'speed faults guide at the top of the forum, and hope someone who knows a bit more than me comes along and makes suggestions.

John
Community Veteran
Posts: 4,846
Thanks: 296
Fixes: 16
Registered: 10-06-2010

Re: Speed very low and erratic

It might also be worth trying simply rebooting the router just in case it's a one-off low speed.

Plusnet Help Team
Plusnet Help Team
Posts: 4,452
Thanks: 226
Fixes: 104
Registered: 01-01-2012

Re: Speed very low and erratic

From what I can see it should be sorted now?

If this post resolved your issue please click the 'This fixed my problem' button
 Matthew Wheeler
 Plusnet Help Team
kjpetrie
Rising Star
Posts: 101
Thanks: 8
Fixes: 1
Registered: 19-12-2010

Re: Speed very low and erratic

Partially, in that the ADSL speed is now back up, but the download speed is still only 0.48Mb/s, so little improvement in performance. The BT diagnostics page reported as follows:

 
FAQ

Results Image not loaded

 

 


1. Best Effort Test: -provides background information.

  Download  Speed
  0.49 Mbps
   
0 Mbps 4 Mbps
Max Achievable Speed

 Download speedachieved during the test was - 0.49 Mbps
 For your connection, the acceptable range of speeds is 1.2 Mbps-4 Mbps.
 IP Profile for your line is - 3.52 Mbps

2. Upstream Test: -provides background information.

  Upload Speed
  0.38 Mbps
   
0 Mbps 0.45 Mbps
Max Achievable Speed

Upload speed achieved during the test was - 0.38Mbps
 Additional Information:
 Upstream Rate IP profile on your line is - 0.45 Mbps

kjpetrie
Rising Star
Posts: 101
Thanks: 8
Fixes: 1
Registered: 19-12-2010

Re: Speed very low and erratic

And here is the current data from my modem:

Link Information
			
Uptime:	0 days, 7:19:44
DSL Type:	G.992.3 annex A
Maximum Bandwidth (Up/Down) [kbps/kbps]:	1,020 / 3,468
Bandwidth (Up/Down) [kbps/kbps]:	444 / 2,936
Data Transferred (Sent/Received) [MB/MB]:	13.26 / 125.31
Output Power (Up/Down) [dBm]:	12.5 / 18.0
Line Attenuation (Up/Down) [dB]:	30.5 / 49.0
SN Margin (Up/Down) [dB]:	23.5 / 4.0
Vendor ID (Local/Remote):	TMMB / IFTN
Loss of Framing (Local/Remote):	91 / 0
Loss of Signal (Local/Remote):	1,048,563 / 0
Loss of Power (Local/Remote):	0 / 0
Loss of Link (Remote):	0
Error Seconds (Local/Remote):	2,883,573 / 0
FEC Errors (Up/Down):	0 / 1,087,946
CRC Errors (Up/Down):	61 / 1,669
HEC Errors (Up/Down):	104 / 16,840
jab1
Seasoned Pro
Posts: 1,335
Thanks: 219
Fixes: 5
Registered: 24-02-2012

Re: Speed very low and erratic

@kjpetrie - can we see a current BTW test?

Your LOS and error counts look horrendous to me (I'm no expert, btw)

Edited to add:

Have you tried a single disconnect/reconnect from the router interface?

John
kjpetrie
Rising Star
Posts: 101
Thanks: 8
Fixes: 1
Registered: 19-12-2010

Re: Speed very low and erratic

BTW test? I thought that was what I've posted above, showing the speed about a tenth of what the profile suggests it should be.

Yes, all the errors suggest something's horribly wrong on the line somewhere, but there's little I can do about that, as all ISPs (apart from Virgin, most of whose customers seem to wish they were with someone else from those I know) depend on the same BT-controlled pair of wires, so even if I moved to a different provider I wouldn't get a better service. Something's gone bad in the last few days and I suspect it's the line.

 

I've tried disconnecting and reconnecting from the router interface, but that makes no difference. (Unless you think a speed change from 0.49 to 0.54 is enough to call a difference.) I'm reluctant to disconnect the line to play around with that because I know every loss of sync is treated by the DLM as an indication the profile is too fast and gets the speed capped ever lower.

jab1
Seasoned Pro
Posts: 1,335
Thanks: 219
Fixes: 5
Registered: 24-02-2012

Re: Speed very low and erratic

Sorry - I was not trying to 'teach granny to suck eggs' - sorry if it came across that way.Embarrassed

Obviously, despite the inference in @MatthewWheeler 's last post, your connection is still terrible, and if you have an open ticket on this I suggest you ask PN to re-evaluate.

John
Plusnet Help Team
Plusnet Help Team
Posts: 4,452
Thanks: 226
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Registered: 01-01-2012

Re: Speed very low and erratic

Fix

@kjpetrie Can you try disconnecting then reconnecting one more time?

Your line speed was set incorrectly which will be why your speeds were still low.

If this post resolved your issue please click the 'This fixed my problem' button
 Matthew Wheeler
 Plusnet Help Team
kjpetrie
Rising Star
Posts: 101
Thanks: 8
Fixes: 1
Registered: 19-12-2010

Re: Speed very low and erratic

NB I did the below and posted before reading Matthew's post above. It seems the only relevant thing below is the reconnection involved!

Well, how embarrassing! My reluctance to play with the line beyond disconnecting the phones proved my undoing. I have now replaced my microfilter and my download speed has gone up to 3.8 Mb/s! I'm not sure whether it is the change of filter or simply the act of unplugging it and plugging in the new one which enabled things to come right. I did notice some grit or grime around the plug of the one I took out, so I wonder whether dirt could be the problem.

Anyway, despite my conviction the problem was outside my house, it appears that wasn't the case. This appears solved for now, anyway.