Downstream Connection speed has been reduced from 3600 Kbps to 2400 Kbps

[#1]

Hi,
Until Mid March my router would always get a downstream connection speed of around 3600 Kbps, this would give me a 3000 Kbps broadband connection . I now get a router downstream connection of around 2400 Kbps which gives me a broadband connection of 2000 Kbps.
Has this permanent reduction in speed happen to anyone else?
Dan.

[#2]

Check your noise margin - the aim is for 6dB, but if yours has been increased your sync rate will decrease.
Is your router connected to the BT socket?

[#3]

Netgear  DG834PN router stats
ADSL Link                  Downstream      Upstream
Connection Speed    2400 kbps          448 kbps
Line Attenuation        55.0 db              28.0 db
Noise Margin              15.5 db              19.0 db
Connected to extention point, I have connected to master socket with no imporvement.
Dan

[#4]

Please ask PN to reduce that Noise Margin - take their advice for the value and stick with the master socket permanently (if possible).
Take advice from them about the 15dB - try for perhaps 9dB.
This will take several phone calls as you need to get PN management (fairly easy) to hound BT management (fairly hard).

[#5]

Thanks for you help.
Just seen thread "Ongoing Sync Issues..." I'll give that a read and try your advice with PN on the noise margin.
My current speed

Been have some line disconnect issues. BT say nothing wrong
Dan.

[#6]

Well I finally got my speed back to:

Not what I got before.

It appears nothing has been changed by BT or PN but I have lost a few kbps. (I used to get around 2.800Mbps)
Is it me or are PN support not very helpfull?
Dan.

[#7]

It's your line, or your equipment (filters, phones, etc.)  Repeated disconnections are seen by the BT exchange as a line fault and the noise margin is increased to produce a stable connection.  The 15.5dB would normally be just 6dB on a stable line.
May be worth replacing filters and asking PN to contact BT to reduce your line's SNR.  If the line is stable it will stay there and you'll get a higher connection speed.  If not, you'll be back to a higher noise margin/lower speed.
Hope this helps.

[#8]

Thanks for you comments, using a new filter in the master socket did not change anything. Noise margine stayed the same.
I have raised a fault with PN on this matter and this is what they said.
BT do not class this issue as a fault though as they set a speed fault threshold rate(FTR) on each line and your line has a FTR of 1817k.
PN then decided to patronise me by telling me to RTFM, they just love telling you to read the help pages.
I would advise you to have a read through the information on the following support page as this will give you a good understanding of how MaxDSL works.
http://www.plus.net/support/broadband/products/faqs_and_guides/dslmax_guide.shtml
They have offered to change the Noise Margin to 12dB but the did say it might make thing worse. The exchange I use does not have a LLU presence so I'm stuck with BT. I don't see much point changing ISP as nothing will change still the same rubbish BT line.
Dan

[#9]

Unfortunately PlusNet's experience is that many customers aren't aware of the help pages and for those users drawing attention to the relevant ones does help. One needs to be tolerant of such phrases included in responses; if they aren't relevant to you just ignore them.
I assume you have a record of how your noise margin varies through a 24 hour period, including any blips, so that you have a good idea of the minimum level reached. Knowing that, and general behaviour of your connection, will allow you to decide whether reducing the target noise margin as PlusNet suggested is likely to make your connection less stable, or not.

[#10]

I would take up the offer to reduce that noise margin to 12dB - BT's equipment (which sets this value) is not renowned for its accuracy. Provided that your actual noise on your line isn't too great, reducing the margin will increase the sync speed.
If you do nothing then nothing will happen - so try it and hope it doesn't reduce the stability too much!
(Even 12dB is very high - but 15dB is ridiculous).

[#11]

Quote from: Dan

Hi, Until Mid March my router would always get a downstream connection speed of around 3600 Kbps, this would give me a 3000 Kbps broadband connection . I now get a router downstream connection of around 2400 Kbps which gives me a broadband connection of 2000 Kbps. Has this permanent reduction in speed happen to anyone else? Dan.

Yes around mid March my speed reduced greatly. Prior to this point had a very stable connection at or above 2000 kbps which always had a noise margin of 6 db.  As stated this connection was very stable, virtually never got any dropouts.
Whether by coincidence to mid march or through my own actions of needing to isolate power a number of times at home, my speed has reduced to less than 1000 kbps with the noise margin being between 12-15 db, which never gets any lower than 11db throughout the day.
Have tried now for over 3 weeks to get this sorted out, done all the tests aksed of me even though i am sure that the target noise margin has been adjusted and this is the problem.  PN at best can be described as very slow, now whether this is down to them or BT i don't know because getting progress is like pulling teeth out.
What annoys me is that when obviously the target margin has been raised, and there is a plausible answer as to why disconnections have been made, following prior periods of many months of up connections, it seems like you are asking the earth to return to your normal value. 

[#12]

I know the feeling. I was on 12dB noise margin for months, but suddenly back up to 15dB when BT changed to 21CN at the exchange (coincidence? - maybe). Have asked PN to get BT to lower it to 12dB again, but it seems to take time for this to happen, I had hoped that now BT & PlusNet were so closely linked it may have been easier. The only alternative seems to be to leave things as they are and eventually (like several weeks) it may go back automatically.
FYI My RX Atten is a stable 56dB ( long line from Exchange that appears to go to the next village and back again) and I could get sync at over 3000 when at 12dB Noise Margin. I'm now only getting 2528 at 12dB Noise Margin. 

[#13]

Hi guys,
Faults/Supplier relations isn't particularly my area of expertise although I know we've a lot of focus on how difficult it is for us to get simple SNR change requests actioned.
It was a topic of much discussion the last time we got together with BT Wholesale.
I'm going to take a look at your accounts now and see if there's anything I can do to help.

[#14]

Thanks Bob! 

[#15]

Right, here we go then:
@Dan the Van, I think the confusion stems partially from the fact that you originally raised your fault as an intermittent sync issue. Are you managing to stay connected most of the time now? If so, what's your current SNR margin and would you like me to try and get this reduced for you? If so can you raise a speed fault here please.
@DarT, I think what we need to do in your case is lower your target SNR to 9db or 6db. The problem I have with requesting this at the moment, is the fact that you've another type of fault raised on your line (because you're synchronising below your Fault Threshold Rate). This is a little ironic TBH because it's likely the result of your target SNR increasing in the first place! Just needs a call to a department in BT to have the SNR lowered I think. I'll see if I can get onto this.
@gm4jjj, can you raise a speed fault here please and give me a nudge once you've done this. I know you already have a ticket open to address the issue but it makes it a lot easier for me if you use the automated tool.