I used my Thuraya XT lite daily on a 10 day trip almost every night at camp in the VHC and had no problems . I'm connected directly thru Pivotel $15 / month. Not sure if optus go via Pivotel but assume they would to obtain the Aust Mobile Number. I also tested my Isatphone in same locations .It also worked (don't have credit on it thou) but took longer to lock in as it requires a gps signal . Once locked to a gps signal it gives a notification tone that your connected to the service.