JAVA VOIP

Hi;

I try to make a voice broadcasting ( for example: marketing solutions ). This application will use a phone line and calls the entered phone number ( may be application can call phone numbers automatically via a database ) and then it plays the mp3 file or other sound files...

This application can use phone lines directly or over use a network protocol over the internet, like a voip modem.

Does any body know about this application?
I dont want any codes or samples, just want to show me a way that what should i use, which API's or etc.

Best regards...