My mum has the NBN interface box, Telstra modem, and DECT phone, so it
is a rat's nest of cables in the corner of dining room. But she is too
old to cope with mobile phone.
I can understand her getting off Optus. Mine gives me the shits. After
power failure, the landline phone isn't registered. You have to switch
off the Optus modem and on again. Restarting it through the http
interface doesn't seem to be the same as cold boot.