Sky Fibre can use extension sockets

[#1]

Hey guys my friend just got Sky Fibre recently and apparently didnt get a BT engineer come over. He used the same socket as his previous ADSL connection which is an extension socket and it works fine. I also search online and found Sky are now doing self install fibre connections.
Is it the modem that allows this? Because I tried an extension socket using the HH 5 and it didnt work

[#2]

If the master socket is not filtered then wired to extension sockets then you can use the modem in the extension sockets. It's not ideal and you can lose some speed but it does work. Terminals 2, 3 and 5 on the master are just duplicate to the 2, 3 and 5 on the extension sockets.
The newer FTTC installs have a new faceplate fitted which filters the master socket and then provides built in filtered feed to the extension sockets which then can't be used for FTTC or ADSL

[#3]

So technically I can remove the master plate filter, put on the old one then use an extension socket with a filter?

[#4]

It may not work very well if the new VDSL faceplate has the suppression device and ring capacitor combined (I haven't taken one apart to be honest).
I've got a feeling the one that was fitted to my property was just plugged straight into the top of the existing NTE5 socket as I didn't see the engineer struggling with any wiring.
Technically though, if your internal wiring is ok then you could *in theory* use the extension wiring to extend the existing master socket to another location - there are only two wires to connect. You could then put a blanking plate on the old master socket and use the extension as a new master socket.
However, fiddling with the master socket is frowned upon as you shouldn't mess with BT equipment and if your extension wiring isn't twisted pair, you could potentially lose a fair amount of speed.

[#5]

Quote from: HNKS

So technically I can remove the master plate filter, put on the old one then use an extension socket with a filter?

You probably have the old rear parts of the NTE5, with the Openreach interstitial fitered faceplate, and the old faceplate on the front of that.
If so, yes, you can remove that interstitial faceplate and replace the old faceplate,. You will probably not have the shorter screws! The extension with a dangly filter will then work.  You may lose quite a lot of performance, depending on the quality of your wiring, or you may be OK.

[#6]

@picbits
You can do what you like your side of the (real) test socket inside the back box. The Openreach interstitial filter is designed to be fitted with no fiddling with the wiring needed. That's why it's so big and ugly.

[#7]

Indeed although you do need to get the lower (extension) faceplate through the new socket without pulling out any of the wires which could be a little troublesome for someone not used to handling solid core cable.
The engineer who sorted my faceplate out was quite surprised that nothing was connected to my lower faceplate until I pointed out I'd removed the wiring and would be redoing it once he'd gone 
It was one of the easiest installs he'd done and he was quite a nice bloke.