What has happened to my download speeds?

[#1]

Looking for this problem to finally be resolved. Have been with Plusnet for many years with no complaints. Service has been steady, with an average download speed of around 6.5mb. Speeds would fluctuate between 6.0 and 6.7 over a period of many years. Since early August this year, speeds have been fluctuating between 0.3mb and 6.5mb. However, these extremes are both rare. The average speed is around 2mb. What has happened? I raised a fault in August, but no problems were found with the line. Problem now seems to be getting worse. Please help.
DSL Connection
Uptime: 2 days, 18:20:25
DSL Type: ITU-T G.992.1
Bandwidth (Up/Down) [kbps/kbps]: 448 / 8.128
Data Transferred (Sent/Received) [GB/GB]: 1,39 / 1,99
Output Power (Up/Down) [dBm]: 12,3 / 15,8
Line Attenuation (Up/Down) [dB]: 5,5 / 10,0
SN Margin (Up/Down) [dB]:         24,0 / 14,3
Loss of Framing (Local/Remote): 0 / -
Loss of Signal (Local/Remote): 0 / -
Loss of Power (Local/Remote): 0 / -
Loss of Link (Remote):                 -
Error Seconds (Local/Remote): 53 / -
FEC Errors (Up/Down):                 97 / 3.993
CRC Errors (Up/Down):                  29 / 78
HEC Errors (Up/Down):                 -9 / 78 / 112
BT Speedtest results
Best effort test: 2.33mbps. Max achievable speed: 7.15
Acceptable range: 0.6-7.15mbps
Your DSL connection rate: 8.13 down. 0.45 up.
Ip profile for your line is: 7.15mbps
I have performed all the basic steps on my side, with no increase to line speed or performance. I am plugged into the main socket. I have performed a quiet line test and it appears to be fine. Please help.

[#2]

Hi Robbie,
Welcome to the forums and thank you for providing most of the information required to answer your question.  The only additional piece of information required is the "Current Speed" (PN Profile) figure reported in the user portal here - https://portal.plus.net/my.html?action=data_transfer_speed
Looking at your stats your ADSL(1) (possibly 20CN) line is doing exceedingly well, therefore the cause of slow DATA speed must be one of...
The PN profile is wrong (see above) it should be 7.15Mbps
Your exchange is over loaded / has congestion
There is a problem with "hidden" profile settings within the BT Wholesale systems.
PlusNet CRT should be able to advise on these directly.  Given the line stats you should be seeing the top end of those DATA speed tests most of the time.  Note were those tests wired or over wifi?  The issue could be the wifi connection, not the internet link.
I'm guessing that you are on a market 1 exchange for which there is no forecast for upgrading to 21CN - which looking at your line stats might deliver you a synch speed of 24Mbps - you must have line-of-sight of the exchange?

Kevin

[#3]

Hi robbie44,
Just checking your profile on both sides of the network (us and BT) it all seems to match up correctly however as Kevin points out, this could well be the result of a different issue. There doesn't appear to be any mention of a congestion issue for the exchange you're on either so I guess it may well fall to confirming how the test was carried out (wired or wireless) and if you've noticed any noticeable changes since the test this afternoon.

[#4]

Thank you for the quick response. Test was over wifi, but have done multiple wired connections and the results are pretty much identical.
Townman: The PN profile figure is 7.15, as you suggest. It is 20CN. Advantage of a small town is the exchange is nearby everyone. Disadvantage is it's 20CN?!
Just completed a wired test and the bt speedtest results are: 1.4mbps download speed. This is a pattern. Speeds start off best in the morning and deteriorate throughout the day, to the point where Youtube is at best a blurry mess.

[#5]

Quote from: Adam

There doesn't appear to be any mention of a congestion issue for the exchange you're on

Adam,
Given Robbie's update, I am lead to ask if there is anything happening on an "upstream / parent" exchange (if there is one) for his local exchange?

Robbie,
This is quite odd - it leads me to wonder if you are suffering from REIN.  This is tricky to identify, locate and eliminate, however it would be useful to rule out / in.  Could you please obtain RouterStats from here - http://www.vwlowen.co.uk/internet/files.htm and configure as explained here - http://community.plus.net/forum/index.php/topic,128606.msg1122269.html#msg1122269 ; Ideally this should be left running 24x7 - if the SNRM graph shows any sudden changes, please post some samples.
Kevin

[#6]

Hi all,
I've just had a second dig into the spreadsheets on the capacity and I've managed to pull up some more detailed information on the exchange and I'm afraid its bad news. It appears that of the 8 Virtual Paths that are shown for the exchange, all are amber with the exception of two that are red which means that this is likely to be the cause of the latency issues during peak times.
Thankfully it seems that the two red VP's are due to be increased however this isn't planned to go ahead until the 30/10/14 which is understandably quite a wait which isn't going to be ideal however it seems to be a relatively small exchange.
I'm afraid that there is little we can do to fix this as it is something that BT handle personally and given that no VP's are in a green or blue status, there isn't going to be a real benefit for asking them to move the connection over to an alternate VP.

Given the status of the exchange I would have expected to see this as an issue that's been ongoing for some time so is this something you've seen in the past?

[#7]

just got the RouterStats software up and running, then checked back here. Now, I'm alright with a keyboard and screen in front of me but get a little lost on terminology. So in Layman's terms....
How do VP's work?
Blue is? Green is good? Amber isn't good and red is bad, but what does that all mean and why is it the case?
Am I amber or red, or does it not work like that? If red, would it not help even a little to move to amber VP?
You say the 2 red VP's are due to be increased on 30/10/14. What does this involve and in what timeframe is the work likely to be completed?
I understand that this is a problem out with your control, but I would really appreciate your time and knowledge, if you could explain some of these things for me.
I haven't seen noticeable drops in speed until August this year. There were a couple of occasions in June and July where online gaming was affected, but general internet use and streaming was fine for the most part. Gaming since August has been impossible. Streaming has been blurry yet bearable. In September I've seen more spinning wheels than content. At this rate, I'll be lucky to view this forum by November.  
Nearby exchanges are due to be upgraded to 21CN within the next 6 months. They are approximately 4, 10 and 12 miles away, effectively creating a 20CN hole in the middle, where I live. Considering the information you have, do you think it's likely they will upgrade our exchange next?

[#8]

Hi Robbie,
VP = Virtual Pipe - it is a logical segment of a physical back-bone bearer circuit.  It is a way of managing capacity and traffic routing into BT's network and on to PlusNet.
An individual's traffic is amalgamated with other users at the exchange and grouped into a VP for onward transmission.  As more and more users are connected to an exchange and they use more bandwidth these pipes "fill up" - more or bigger pipes need to be provided to move the increasing volume of traffic more speedily.
Green, Amber and Red you have got pretty well.  Blue means they are starting to become heavily loaded - one would have hoped that BTw were doing a more proactive job of monitoring VP utilisation and were moving to upgrade Blue VPs before they turn Amber or Red.
The time frame and hassle of moving VPs would not I suggest make it worth while attempting to move from a red pipe to an Amber pipe.

[#9]

Oh well, I guess I just need to sit tight, grin and bare it. Thank you Kevin and Adam for all your help. Even though I can't do anything about it, at least I now know that. Just hope it isn't a long process and that the exchange gets a further upgrade in the new year.

[#10]

townman forgot to mention PN as a cause of congestion, its been congested for 2-3 days now I think due to misbalance and possible downgrading of capacity per end user.