VoipBuster is one of several Internet telephony services (also called VoIP-service) of Betamax GmbH & Co. KG in Germany. Formerly VoipBuster was a service of Swiss based Finarea SA. VoipBuster uses a client software with proprietary protocol, but can also be accessed via SIP-protocol. VoipBuster features low call rates. Subscribers can mutually call for free, and call for free to fixed lines in selected countries worldwide (0 pennies per minute and no start tariff) for a limited number of days after payments to VoipBuster.