This
...
feature allows users to make outgoing calls using the native GSM dialer (on mobile devices with GSM only). As an administrator, you can provide an Access number which will be added infront of the destination number.
How does it work
In the Ringotel iOS or Android app, open a contact profile from the contacts list or a phone book. Alternatively, open the contact’s conversation panel.
Long-tap on the phone icon.
In the provided menu, tap on the GSM call.
Alternatively, click the GSM call button in case of an unsuccessful connection.
