I've checked the POTS entry from the post above. It shows "x.xxxxxxxxxx" presumably because when it didn't work I took exact match off. Where in the web portal do I find "ITSP InboundCallRoute"?
If you're configuring the OBi directly, you'll need to disable Auto Provisioning at:
System Management -> Auto Provisioning -> Auto Provisioning -> Method : Disabled
For SP1:
Voice Services -> SP1 Service -> X_InboundCallRoute : {0412345678:aa},{ph}
For SP2:
Voice Services -> SP2 Service -> X_InboundCallRoute : {0412345678:aa},{ph}
For LINE Port:
Physical Interfaces -> LINE Port -> InboundCallRoute: {0412345678:aa},{ph}
where 0412345678 is your mobile number.