Hi @dial000 . VOIP phone service won't work on new router. Also won't work with FTTB/FTTN.
On the VR1600 EWAN config, you'll see PPPoE, username and password, and if VLAN ID is enabled and a value (2). These are the settings to go in the AX5400. First 3 are easy. The 4th is tucked away in IPTV/VLAN section. Manual is not clear about this but see the iiNet article for similar setup.