Intermitent Slow broadband speed

[#1]

Worth trying directly in the test socket behind the NT5 if that can be managed?  Just to eliminate anything to do with the extension wiring.

Another thing, if you want to go into more detail the 582N is supported by DSL Stats (http://www.s446074245.websitehome.co.uk/index.html) which can give you a picture of errors etc over time.   

[#2]

I would not use DSLStats on the 582n @aesmith it fills up the router log with log in/logout entries and other log entries (that can be of use when analysing dropping connections etc) will be lost once the cache is full as new entries overwrite the old.
You are better off using RouterStatsLite or the Full version of RouterStats if you want to spend time setting the latter up.

Edit: Just to add, that generally with low levels of errors it's not often worth monitoring the errors (which you can't do anyway with the Lite version of RouterStats) as if there are any significant errors at an instant, these generally show up as a disturbance in the SNRM. Again, in general the SNRM variations can tell you a lot about the general state of the connection. If specific issues get identified, it can then sometimes be worth monitoring some errors in more detail.

[#3]

Now I am completely lost. The internet is absolutely terrible at the moment,

My sons Xbox One says his download is 147kbps.

BT Wholesale are telling me

1. Best Effort Test: -provides background information.

	Download  Speed
	15.21 Mbps

0 Mbps

4 Mbps Max Achievable Speed

 Download speedachieved during the test was - 15.21 Mbps
 For your connection, the acceptable range of speeds is 1.2 Mbps-4 Mbps.
 IP Profile for your line is - 2.79 Mbps

2. Upstream Test: -provides background information.

	Upload Speed
	0.47 Mbps

0 Mbps

0.83 Mbps Max Achievable Speed

Upload speed achieved during the test was - 0.47Mbps
 Additional Information:
 Upstream Rate IP profile on your line is - 0.83 Mbps

We were unable to identify any performance problem with your service at this time.
It is possible that any problem you are currently, or had previously experienced may have been caused by traffic congestion on the Internet or by the server you were accessing responding slowly.
If you continue to encounter a problem with a specific server, please contact the administrator of that server in the first instance.

Speedtest.net gives me, well nothing to be exact. After trying 5 times to get the "Begin Test" to run it simply gives up and stops.

BT Wholesale 5 minutes later.

Download  Speed
	2.36 Mbps

0 Mbps

4 Mbps Max Achievable Speed

 Download speedachieved during the test was - 2.36 Mbps
 For your connection, the acceptable range of speeds is 1.2 Mbps-4 Mbps.
 IP Profile for your line is - 2.79 Mbps

2. Upstream Test: -provides background information.

	Upload Speed
	0.77 Mbps

0 Mbps

0.83 Mbps Max Achievable Speed

Upload speed achieved during the test was - 0.77Mbps
 Additional Information:
 Upstream Rate IP profile on your line is - 0.83 Mbps

This is now getting ridiculous can this please be escalated up in Plus.net to try to get resolved. As I have said before nothing has changed in the wiring, hardware, or anything. It is simply unusable at the moment.