Unable to make outbound calls due to the "Registration failed due to STUN server (DNS resolving or connection) code: 59" error in Zoiper.
The following changes should be made:
- Click Settings>Accounts>Account name
- Navigate to the Advanced tab on the top right hand corner
- Scroll down to the Network related section
- Locate the "Use STUN" option and select "Don't use STUN"