Viettel Caller Ring Back Tone (vCRBT)
vCRBT is a service enabling users to select and change the ring-tone music of incoming or outgoing calls while waiting for a connection.
• vCRBT is a service enabling users to select and change the ring-tone music of incoming or outgoing calls while waiting for a connection.
• Deployed in the markets of Vietnam, Myanmar, Laos, Timor Leste.