Well I'll just say it was for me when I've done it before.
Once I unlocked the HG612 I only ever really looked inside it to get the connection stats I think and to do something with the TR-069 stuff.
@TimCurtis Unlocking and using with VDSL is indeed trivial, but ADSL with PPPoA is a whole different ball game.
The USG has two WAN ports, I have not got there yet, but the plan was to have both my 7mbs BT Broadband in one and my 24mbs EE 4G into the other. I believe it is then possible to have so much IP load on one and so much on the other. So effectively increasing my bandwidth.
We live in a rubbish area for high speed internet access. Indeed on same site I have another EE 4G router to get internet into another building (Holiday cottages). So I am paying for 2x Unlimited EE SIM's and the BT Broadband.
Step 1 was to get the USG working with load on 2 WAN connections, i,e. 1xBT & 1xEE 4G.
Step 2 was to trial Starlink as replacement to the EE 4G.
Step 3 was to ditch the second EE 4G on the other building and beam a wireless network connection off the main network over instead, probably off a separate VLAN off the switch. The StarLink should have a higher bandwidth and be able to serve both properties. The BT Broadband would remain as something of a backup. Just in case Putin starts shooting down satellites or Elon goes bust.
So as you can see this is just step 1...
Ok, from what I have learnt, it would appear that the HG612 in locked default configuration can be used with both ADSL and VDSL. For ADSL, PPP parameters can be entered on the router WAN as PPPoE and the HG612 then forwards the credentials as PPPoA with VPI/VCI hard coded as 0/38.
I think I have it licked...
I eventually got both my HG612's unlocked and the webgui firmware loaded as per the Kitz instructions above. What seem to do it was taking the boards out of the box so I could be sure the reset button was getting pressed.
So I got this on 192.168.1.2 (I changed the webgui IP address in the LAN settings first so it did not clash with my USG Router webgui).
With the hint about PPPoA from everybody above I found these instructions :
So I pretty much followed them with success. The only bit I found to be missing was to first setup the ATM here before being able to see it in the layer 2 interface drop down :
After that my USG reported internet connectivity :
Speed testing on the USG I am getting pretty much the same result as the BT Home Hub :
So thanks everybody for persisting to think about my problem with the HG612.
PS. I now have a spare unlocked HG612 with the JTAG/Serial Port header fitted. I.e. direct serial console access is possible. Not sure how to work it though...
Glad you finally managed to get it working.
Despite my earlier assertion, from further information, it now seems that the HG612 will not automatically convert the PPPoE credentials from the router to PPPoA but needs to be configured as per the link I posted which you have followed successfully.