Systems and methods which utilize existing, or otherwise available, voice over Internet protocol (VoIP) infrastructure for providing calling services with respect to controlled environment facilities, while continuing to implement a desired level of call mastering, are shown. VoIP infrastructure utilized according to embodiments may be provided by various alternative carriers, such as may have initially have been deployed for providing reduced rate calling services to individual users. Where possible, a call processor adapted according to embodiments may implement some of the same call mastering functions with respect to calls using VoIP infrastructure links as for more traditional call using PSTN links. However, embodiments additionally or alternatively implement functions uniquely tailored to the use of VoIP links. Embodiments allow user selection of the use of VoIP infrastructure.