An inquiry will be launched into domestic roaming, allowing phones to switch networks. (George Chan/AAP PHOTOS)An inquiry will be launched into domestic roaming, allowing phones to switch networks. (George Chan/AAP PHOTOS) Credit: AAPMajor telcos remain divided on an inquiry into whether customers should be able to use a different mobile network if they are left without service. The watchdog said it would only declare mobile providers share their infrastructure if it will benefit Australians. A Telstra spokesperson said the telco opposed mandates for domestic mobile roaming.