The bandwidth required to make a VoIP call is dependent on the audio codec used.

The most common codec used in Australia is the G729 codec which uses just over 13MB of data per hour when making calls.

A slightly higher quality codec which will require more bandwidth is the G711A codec, this will use around 39MB of data per hour when making calls. The minimum broadband speed to utilise the G711A codec would be a 512kbps ADSL connection. The data usage when calls are not active is minimal.