Issues getting TP-Link TD-W9970 Modem Router to connect to Sky Superfast Broadband

[SafferUK]

Good morning 

I bought a TP-Link TD-W9970 modem router for the purpose of replacing my current Sky ER115 modem router. 
I believe my Sky Superfast service is FTTC, (31436Kbps downsteam, 4858 Kbps upstream)
The problem I have is that the W9970 just will not connect to Sky. 
Having read through these forums, I believe I should be using Sky(MER)_VDSL, and I've followed these instructions: 

• Input your location and time zone. Click Next.
• Select Sky(MER)_VDSL from the ISP list. Make sure it’s this one, as this is Sky fibre. The other Sky option in the list is for Sky Broadband and will not work for fibre connections.
• In the username field, enter abcdefgh@skydsl
• In the password field, enter 1234567890abcdef
• Click Next, then set up your wireless network how you see fit.
• The TP-Link will then test the Internet connection and you should see a success message. If you do not, wait for the DSL light to stop flashing and try again – it should work just fine.

Sadly, the modem never connects, if I use the setup wizard it gets to 'Testing connection' but never goes any further.
I'm at a bit of a loss how to get this to work. Everything is plugged in correctly, and under DSL settings in the TP-Link interface, it shows my DSL line connected (shows downrate / uprate etc) but I'm not getting the internet light up to show that an actual connection has been made. 
Any guidance would be appreciated. 

[Skull+Treaty]

@SafferUK 

You may have a better experience using this link to use in modem only mode

https://www.tp-link.com/uk/support/faq/1332/ 

[SafferUK · Accepted solution]

Bizarrely, I've just it to work. 
I was under the impression that I could use any combination of letters and numbers for my username and password, but I came across a post by a chap that showed how to find your specific @skydsl username and password using wireshark here. 
Using the exact credentials that my Sky router was using, I was able to make a connection.