WarVOX makes phone calls over VoIP using the IAX protocol developed for Asterisk. Although many VoIP providers do not support IAX, you can leverage a local Asterisk or FreeSwitch installation to route WarVOX to a SIP provider. Most "unlimited plan" service providers have terms of service which place severe restrictions on wardialing and any usage pattern which is outside of the residential norm. If you recommend a specific IAX-capable VoIP provider, please contact us and we can include it in this list. If you would like to dial using a SIP-based provider you will need to setup an Asterisk server and configure the IAX service.
For a list of VoIP providers, please see http://www.voipproviderslist.com/.