Slowly but surely ever decreasing connection speed

[#1]

Over time  time my speed as reported on the portal has been getting lower and lower.  When I first moved to MaxDSL, my router would report connection speeds between approx 5500 and 6500  and the portal would report between approx 5000 and 6000,  it was pretty stable and I was happy with the service. However over time this has deteriorated and over the last 6 moths months I have been getting anywhere between about 1500 and 3500.
For example today the portal show my speed 3000, my router shows date rate as 3968 down and 448 up. SNR Margin is bouncing around between 20-27 down and a steady 16 up. Attenuation is 4.7 down and 3.5 Up, No errored seconds, no loss of signal, no loss of frame, no CRC errors.  These stats are since I restarted  it 13 hours ago.  I have monitored the stats over the last week or two and I do consistently see a few errored seconds ( mostly 0-20, some nights a few hundred) and CRC errors  (mostly 0-150, some nights a few thousand). This mostly between midnight and 8 am, and almost never during the day.
The router is on 24/7,  I don't restart it too often, as I know this can have an negative impact, so for example this morning was the first restart in approximately 4 days, and I did this in a vain hope that I may pick up a higher connection speed.
The router is an Safecom 4 port wired router, it is connected directly to a BT Openreach NTE5 Faceplate using a Belkin high speed internet modem cable. There are telephone extensions, but these are wired with only the two wires, so no ring wire issues.  The local exchange is only a few hundred meters away, and the estate is relatively new (12 years) with all the cabling underground. I had Plusnet check out the line recently, no issues were found, and the BT silent line test is silent. Plusnet did say the could send out a BT engineer, however if no line fault was found there would be a charge of £140
Any suggestions as to how I might improve the speed I am achieving?
Thanks & Regards
David

[#2]

Does your router have logs and can you see anything in these logs if it does? The problems with leaving it on 24/7 is that the line can be dropped and it then connects at a low speed for a day or so thus dropping your profile. You of coarse dont notice whats happend unless you log into your router and check the speed at least daily.
If there is logs it may show what the problem is if not keep checking the router twice a day and check the speed if it drops low turn it off for 5 mins and restart and see if you get a good speed.
Plusnet should be able to tell you if you have dropped the line

[#3]

Hi, yes there are logs, you can also see drops on the stats page of the router. I can go for days with no drops, and then have a day where there are 3 or 4.

[#4]

Quote from: maccoylton

or example today the portal show my speed 3000, my router shows date rate as 3968 down and 448 up. SNR Margin is bouncing around between 20-27 down and a steady 16 up. Attenuation is 4.7 down and 3.5 Up, No errored seconds, no loss of signal, no loss of frame, no CRC errors.  These stats are since I restarted  it 13 hours ago.  I have monitored the stats over the last week or two and I do consistently see a few errored seconds ( mostly 0-20, some nights a few hundred) and CRC errors  (mostly 0-150, some nights a few thousand). This mostly between midnight and 8 am, and almost never during the day.

There is something a lot wrong with your downstream noise margin. I can only think that there must have been a resynch overnight. Can you do a resynch and report back the stats- speeds, attenuation and noise margin immediately after the resynch.

[#5]

Re-booted the router and here's the stats from the system log as it came back on line
01/01/1970 00:00:16> CO Vendor: TEXAS_INSTRUMENTS
01/01/1970 00:00:16> d/s SNR: 21.2dB, u/s SNR: 14.0dB
01/01/1970 00:00:16> d/s Attenuation: 4.6dB, u/s Attenuation: 4.0dB
01/01/1970 00:00:16> d/s Data Rate: 4608kbps, u/s Data Rate: 448kbps
01/01/1970 00:00:16> d/s Latency: INTERLEAVED, u/s Latency: INTERLEAVED
01/01/1970 00:00:16> d/s total bit capacity: 1603bits, used: 1288bits
01/01/1970 00:00:16> u/s total bit capacity: 153bits, used: 153bits
Thanks & regards
David

[#6]

Something is badly wrong.
As far as I know the maximum default noise margin is 15dB so why you have 21.2 dB I have no idea.
However there is another problem. If that attenuation is correct there is a major noise problem on your line.
Can you connect to the test socket behind the master socket with nothing else connected and try another filter

[#7]

HI,

that was something PlusNet asked me to try a few weeks back when I contacted them around this issues. Using the test socket didn't make much difference to the SNR Margin numbers. BTW the NTE5 Faceplate is relatively new, I bought it to replace the microfilters I had been using on the extensions in an attempt to get to the bottom of this.
You say the SNR Margin looks wrong, what kind of value would I be expecting to see for this, I was maybe incorrectly under the impression that lower attenuation and higher SNR Margin the more chance you have of getting higher speed, maybe I miss-read all the background info.
Thanks
David

[#8]

Basically the noise margin is the amount of headroom you have at a given synch speed.
if you were synching at the full ADSL speed of 8128 then a high noise margin is good and given your attenuation that is exactly what you should be getting.
However your synch rate is only 4608 so the default noise margin (what BT set at the exchange) is limiting your speed.
When you say you replaced the NTE5 faceplate was that replacing the lower part with something like the ADSLNation XTE-2005 or did you replace the whole of the NTE5 unit.
If you replaced only the lower half I assume you connected the extension wires to it. In which case you should still try the test socket behind it with nothing else connected.
Just a further check - you haven't got an alarm or Sky box hard wired somewhere

[#9]

Thanks for sticking with this.
It was the lower faceplate. The one I purchased, Is branded BT Openreach, and on the front it says ADSL v1.0. The extensions are wired into the back of this, two wires only, so no bell wire. 
Again I already tried using the test socket, it didn't make much/any difference to the SNR margin.
No Alarm system, and Sky boxes are connected to the extensions, so when using the test socket this should not come into it.. Have also tried disconnecting the Sky boxes form their extensions to se if one of them was causing any noise.
BTW I've a new wireless router coming from PlusNet this week, so when I get that I can then rule out the last piece I haven't changed/tested ie my existing router.

Regards
David

[#10]

As a matter of interest when BT were trying to solve a problem on my line (they didn't but that is another story) they fitted a BT filtered faceplate which after a couple of months started playing up so I went back to my ADSLNation one.

[#11]

New router arrived today from PlusNet - Thomson 585 v7. So far so good,

Bandwidth (Up/Down) [kbps/kbps]: 448 / 7,456
Line Attenuation (Up/Down) [dB]: 2.0 / 4.0
SN Margin (Up/Down) [dB]: 23.0 / 15.0
Numbers look good, so maybe, just maybe the router was the problem all along

[#12]

If those are the figures just after resynch of the router your default noise margin is 15dB which was probably down to the old router.
If you leave it alone it should eventually drop and you will get the full 8128kbps.
Alternatively if it remains stable for a week or so you could raise a ticket asking for it to be reduced.
To be honest in practice you probably won't notice the difference

[#13]

Quote from: Oldjim

If you leave it alone it should eventually drop and you will get the full 8128kbps.

It won't because interleaving is on.  But we can always arrange to have that turned off.

[#14]

[Censored]  but he might get 7616

[#15]

Jamesh assume I need to raise a ticket to have interleaving turned off ?