The modem LAN1 should connect to the router WAN using an ethernet cable. Scenario 2 below
I've connected the devices using scenario 2 🙂
I've been into WAN settings, 'WAN transfer mode' is set to 'ADSL WAN (ATM)'.
In the PPP settings, I've put firstname.lastname@example.org as the username and the password left blank. But the DSL connection screen still does the same thing