Connection getting very slow at night

[#1]

Hi Guys
Hoping one of the Plusnet tech people can shed some light on an issue that has been playing up for about a week now:
After about 9pm my throughput speeds seem to plummet and become quite erratic. All other times sees a stable 3.6MBits. Stats from tonight

Uptime: 5 days, 2:48:30
DSL Type: G.992.3 annex A
Bandwidth (Up/Down) [kbps/kbps]: 968 / 4,679
Data Transferred (Sent/Received) [MB/GB] 177.83 / 1.71
Output Power (Up/Down) [dBm]: 13.0 / 0.0
Line Attenuation (Up/Down) [dB]: 27.5 / 48.0
SN Margin (Up/Down) [dB]: 5.5 / 2.5
Vendor ID (Local/Remote): TMMB / IFTN
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 0 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 2 / 0
FEC Errors (Up/Down): 0 / 11,183,842
CRC Errors (Up/Down): 0 / 411
HEC Errors (Up/Down): 0 / 350  
My local exchange is Chippenham if that's any help and my router is rock solid. I'm on the Plusnet Pro package so should not be seeing any traffic shaping. All I can think of is that the exchange is running hot.
Help appreciated.

[#2]

Hi ComplexP,
yes, contention at the exchange is one of a number of possibilities, especially during the world cup. A few other things worth looking at are what you are doing or what else is happening at the time.
Is your computer downloading updates of some sort at this time?
Are there any other users at the property that may be downloading large amounts of data?
If you have a wireless router, is it a secure network, and have you checked there are no other users connected to it?
Obviously those suggestions aren't exhaustive, but a good place to look is http://community.plus.net/blog/2007/07/02/broadband-speed-faults-how-to-diagnose/ as there's plenty of useful information there.
Jojo

[#3]

Hi Jojo, thanks for the reply.
The answers to those particulars are no, no and yes. I'm a veteran of a previous, very nasty line fault that was finally tracked to a loose wire up at the pole outside my house about a year ago but it took 18 months and 4 Openreach engineers to find so I'm quite familiar with the various local causes of broadband problems.
I'd be willing to bet on contention being the issue and have raised the 'fault' so that it can be passed to BT although I'm not sure what BT can do about it or whether they would care about a single user on a large exchange :(. Hopefully it will go away by itself once the WC is over. Interestingly it didn't seem so bad last night.
Fingers crossed.

[#4]

To be honest ComplexP, I think the world cup this time has caused a lot of issues. Yesterday when the England game was on there were record amounts of traffic, with the capability of lines and the explosion of technology since the last world cup. So, I'm sure that contention seems the favourite one at the moment. If you've raised a fault though that's probably the best way to get it looked at.
Jojo