Duo Voice uses real telephone lines, which means we can guarantee a good crystal clear voice call quality, such as telephone calls from a landline! Duo Voice automatically detects and adjusts your connection speed to make sure more stable calls.
Duo Voice is a FREE calling app that offers international calling and quality of phone call locally and abroad.
Voice calls are sent to high quality Duo Voice's dedicated VOIP network so that you do not need to worry about bad reception, volatile calls or drops.
Our system always finds the best telephone line (the best voice quality) in your neighboring region when you make the call.
(3) Duo Voice uses an internet call (aka WiFi call, IP call, or VoIP call).