FTTC Speed and Installation questions

[#1]

Hi,
I had FTTC installed a week ago, and have a couple of queries as follows.
On checking my speed with mybroadbandspeed.co.uk I am getting speeds between 20000/22000 kbps download and a consistant 1670+ upload. With  speedtest.net  I am getting around 170000, I am using kilobits as a measurement which I believe is the same as mybroadbandspeed measurement. Can somebody tell me which is the more accurate reading?
My BT IP profile is  38717 and the test showed 35823Kbps. As my speed with Pipex/TT was 1800 I am not complaining just wondering what the correct speed is.
My second query is regarding the installation, when we moved here a number of years ago we had a problem with street lights and connection. Pipex arranged for a BT Engineer, who installed an extension cable from my master socket into the loft and down into the office (the property is a bungalow) and I would estimate the cable to be around 15m in length, and is standard BT cable.
I informed the Openreach Engineer of the set up and he utilised the same cable to set up the connection and replaced the face plate on the master socket and connected the modem to the extension in the office. Is standard BT cable as used in this installation sufficient or should he have installed the Data Extension kit as ordered or is there no difference?
Many thanks in advance for any help.
Natchez

[#2]

Hi Natchez,
Due to the configuration of our network and traffic management platform the BT speed tester will always give you the most accurate representation of your line speed.  This is because the BT speed tester is not affected by our traffic management policies whereas other speed testers can be affected and so do not give the best results.
With regards to the installation the data extension kit ordered this would very likely be of the same type as your currently installed extension.  Since your line is connecting in the region of 40Mbps it is clear that the line speed is not being negatively affected by the use of said extension.
If you have any further questions just let us know.

[#3]

I have an IP profile of 38717 too, which means the line is sync'ing at 40Mbps.
With this setup, I find that the BT tester is both more consistent (in that you get the same results 24x7) and less consistent (in that the results can vary between 31 and 35Mbps).
I find "mybroadbandspeed" to be middling in consistency, but with no real reason as to why it might be slow when it is (ie not in busy hour; not being traffic managed).
I find "speedtest.net" to give the most consistent results, provided that I choose the right server (Newbury always gives me the most consistent rules) and that I choose to run the test outside any traffic-managed hours (for browsing, this is 6PM - 11PM). I also run the tests with wired ethernet, as wireless does introduce a random element.
During traffic-managed hours, you would expect the speedtest.net results to show something in the region of 20-24Mbps. Outside the managed hours, I tend to either get 35Mbps or 37.5Mbps (the difference is reported in a different thread).

[#4]

Hi,
Thanks for your replies you have both been very helpfull. I will try another test after 6pm.
Many thanks
Natchez