Could be rogue Fax machine but likely scam call of some sort? BECAUSE .. answered incoming call from an (08) number first/just getting a repeating 'tone' like a fax would give waiting to be switched to the receiving fax (if you know/you know) ... BUT once I hung up, I then got THREE MORE identical calls, less than 30secs after I hung up each time .. from 3 different (07) numbers? .. THEN about 5mins later got another incoming call/same thing but from an (02) number ... then another 5 mins and ANOTHER call from (this) FOURTH (07) number ... VERY ANNOYING!!!!

Fax or modem calls all night.