Many thanks for this guide. It must have taken you a while to work it all out and document it.
I started by upgrading the firmware to 1.0.59.3 (as at 8/4/25). In that version there is just one small difference to your document.
Point 6 says to find the "SLIC" setting in Advanced Settings. I found it in the FXS Port tab.
Again, thanks for taking the trouble to post the instructions. I'm sure they saved me hours.
