This article is only applicable for non Microsoft Teams Account.
Playing a ring back tone is normally the duty of the User Agent, though there are some usage cases for @voice to play it from its side. The feature could also be used in the case of the caller's User Agent is misconfigured or outdated and is unable to play a ring back tone to the caller.
With 'Generate Ring Back Tone' enabled, @voice plays a ring tone to the Caller when the call is in a provisioning state, case being a 180/183 has been received from the end carrier, up to receiving and processing 200 OK from the carrier.
Supported Coded formats supported by this feature:-