I haven't said this yet. So I'm going to say it now. Thank you for your responses and the time you have taken to respond. It is greatly appreciated because I'm learning a tremendous amount albeit the problems haven't gone but at least I can try other ways to ensure my internal network is bullet proof. If I have come across as a bit unpleasant I apologise as that is not my intention however it can come across that way after reading back through my posts.
To answer the question raised about the access points, as someone mentioned the latest firmware on the Linksys devices turn them into an access point and they are updated to the latest firmware. They have been in place since before the switch to Plusnet and weren't causing any problems.
I have ensured that all devices were powered off and rebooted one at a time, although I didn't switch off the wireless.
I have signed up to the BQM and will perform the LAN tests across my network when I get the chance to and report the results here.
As for the master socket, I'm not competent to change this over to the old one and I don't have the old one to even try, unfortunately. I will be speaking to Plusnet again and ask for another engineer to come out.
You will be hard pushed to get an engineer to come out if Plusnet can't detect a fault, it's not impossible, but the staff member dealing with it will probably have to get an override from a manager to get an engineer sent out, if the manager is told there is no fault and the hub gets 65-Mbit then its very unlikely they will 'green-light' an appointed visit, situations similar to this are usually dependant on the resilience of the manager & customer, managers may cave in with threats to leave...but not always... if a fault is found internally by BTo they will inform the ISP who will in-turn forward the circa
£130 £65 bill from BTo to yourself, whether its fixed or not.
Its really quite easy swapping NTE's, plenty of videos & guidance online and you can pick them up cheaply off ebay or other sites. The wires are coloured and the NTE's labelled, its literally 2 wires, A wire and B wire, write down which colour wire goes into A and B, then remove the NTE5C, pop in an NTE5A..A-to-A / B-to-B, the wires just push down into the IDC slot. Any extensions you may have around the home are fitted to terminals 2 and 5 on the front plate, bell wire
(should be avoided if not needed) goes into terminal 3, it may or may not resolve your dropouts but it is worth a try, out of simple curiosity...it would have been interesting to know just what your 'Error Rate'
(such as CRC, FEC, ES over time) was before and after an NTE5C install! I know its not going to fix your problem, but if you get the same symptoms as I did from the NTE5C then its possible that DLM could later at some point intervene and increase the SNRM and/or your error protection values
(and thus lower your sync speed) to make it more stable
(less errors), I'm not saying it will happen, but could.
[youtube]https://www.youtube.com/watch?v=5UxkSUaMVM8[/youtube]