THIS WIKI HAS BEEN UPDATED FOR VERSION 13 OF YOUR PBX GUI
Sysadmin 13.0.73+ provides the new PnP service for sangoma phones.
Utilizing the service requires the sangoma phone exist on the same *network segment* as a FreePBX machine.
Upon iniital boot and you will see a new window on your phone called PNP server.
Order of precedence is PNP -> Option 66 -> rs.sangoma.net